Hair Loss Products

Summary

Sliced Bread – Hair Loss Products
BBC Radio 4 | Host: Greg Foot
Episode Date: December 12, 2024

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Episode Overview

The episode investigates hair loss products—both pharmaceutical and “natural”—to determine whether they truly deliver on their promises or are simply marketing hype. Host Greg Foot is joined by listeners Kimberly Alcock (seeking solutions for menopausal hair thinning) and Ian Baker (navigating male pattern baldness options) alongside leading hair specialist Professor Ralph Pauls (Miller School of Medicine, University of Miami). The discussion covers causes of hair loss, reviews evidence for popular products (minoxidil, finasteride, dutasteride, estrogen, supplements), and critically examines shampoos, serums, and supplements often promoted online.

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Key Discussion Points & Insights

Causes of Hair Loss

[03:54] Prof. Ralph Pauls:

• Four broad causes: hormonal imbalances (too much androgen/too little estrogen), inflammation (immune system attacks follicles), toxic effects (e.g. chemo), and drug side effects (e.g. beta blockers).
• Hair follicles are “mini organs” that cycle through growth, regression, and rest.

“It is a disturbance of this so called hair cycle that gives us increased hair shedding.” (Prof. Ralph Pauls, 05:11)

Differences between Male & Female Pattern Hair Loss

• Male: Primarily driven by DHT (dihydrotestosterone), a derivative of testosterone, which miniaturizes follicles in specific, genetically pre-programmed areas.
• Female: More diffuse; combination of relative estrogen deficiency and androgen effect, especially prominent post-pregnancy or during/after menopause.

“In male pattern hair loss, it is primarily induced by androgens ... in female pattern hair loss, it’s a mixture.” (Prof. Ralph Pauls, 06:17)

Pharmaceutical Treatments Reviewed

Minoxidil

What is it?

• Originally a blood pressure medication; noted to promote hair growth as a side effect.
• Available topically (foam or solution, usually 5% concentration for men, 2%–5% for women).
• Needs long-term (at least 6-12 months) daily use; works only as long as you continue.

Effectiveness:

• Stops progression in more than half of users; some see regrowth, but “cosmetically acceptable” regrowth is rare.
• Effects range from mild "peach fuzz" to fuller regrowth; results highly variable and unpredictable.

“The percentage of patients that actually see hair regrowth that they find cosmetically acceptable, that is much lower.” (Prof. Ralph Pauls, 12:43)
“Patients often give up too early ... the general advice is to give this agent at least a year.” (Prof. Ralph Pauls, 14:13)

Topical vs Oral:

• Oral minoxidil is easier to take but comes with higher risks of systemic side effects (e.g. arrhythmias).
• Topical application preferred for those with cardiac risks.

Finasteride

What is it?

• Tablet that inhibits enzyme converting testosterone to DHT.
• Only licensed for male hair loss due to risk in pregnant women, but sometimes used post-menopause.

Effectiveness:

• 80–90% success rate in stopping further hair loss; needs at least a year for noticeable effect.
• Often combined with topical minoxidil for better outcomes.

Side Effects:

• Debate over sexual side effects (depression, erectile dysfunction); “nocebo effect” may play a role.

“For finasteride, don’t even start it if you’re not willing to take it a year.” (Prof. Ralph Pauls, 20:05)
“It's a minefield ... snake oil products ... glad for Ralph's clarity.” (Ian Baker, 34:42)

Dutasteride

What is it?

• More potent DHT inhibitor; unlicensed for hair loss, but sometimes used when finasteride is ineffective.
• Slightly more effective, but less clinical experience—should be considered only under physician guidance.

Estrogen (for Female Hair Loss)

[23:48] Prof. Ralph Pauls:

• Topical estrogen tinctures help reduce/freeze progression of female pattern hair loss, especially post-menopause.
• “Halts loss but doesn’t regrow hair.”
• Often paired with minoxidil in clinical practice.

“With minoxidil we would then hope that you would get some hair regrowth. And with the estrogen tincture you would halt the hair loss.” (Prof. Ralph Pauls, 24:52)

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Over-the-Counter & “Natural” Products

Shampoos

• Caffeine shampoos have promising lab data (“in principle, caffeine clearly stimulates hair follicles”), but no robust human trial evidence.
• Contact time on scalp is “far too low” for meaningful effect; leave-on tinctures or serums more likely to work.

“No shampoos will give you any predictable hair growth promoting effect ... the contact time is too low.” (Prof. Ralph Pauls, 27:23)

Serums

• Effectiveness depends on ingredients and leave-on application (better penetration).
• Most herbal extracts (e.g. fleece flower, angelica, ginseng) have “poor” or limited evidence for efficacy except possibly ginseng, which may modulate growth factors.

Supplements

• Hair follicles are highly metabolic; proper nutrition is essential.
• Biotin: Good for nails; not convincing for hair unless deficient.
• Vitamin D: Important for health, not for hair growth specifically.
• Collagen: No good evidence for effect on hair; “might as well eat a steak”.

“Collagen … no good evidence … might as well eat a good steak.” (Prof. Ralph Pauls, 32:46)

Brushing

• No strong proof it stimulates hair growth; can “temporarily increase blood supply,” but no lasting benefit.

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Notable Quotes & Memorable Moments

• “It’s much more complex than I thought it was going to be.” — Ian Baker [09:46]
• “You are the one who has to generate the evidence.” — Prof. Ralph Pauls on supplement companies [29:50]
• “The thing that I’ve taken from it is also, if you are doing these things, it’s forever ... it’s a commitment.” — Kimberly Alcock [35:08]

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Important Segments & Timestamps

• [03:54] — Four main causes of hair loss
• [08:25] — Why testosterone/DHT affect different regions
• [13:19] — Minoxidil: What to expect & realistic outcomes
• [14:09] — Importance of long-term commitment to treatments
• [19:04] — What is finasteride and expected effectiveness
• [23:48] — Estrogen tinctures for women
• [27:19] — Why shampoos are not effective for hair growth
• [32:46] — Collagen's lack of proven benefit for hair
• [34:10] — Final verdict: What works, what doesn’t

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Summary Table: What Works and What Doesn’t

| Treatment Type | Evidence & Notes | Use Case | |-------------------------- |------------------------------------------------------------|---------------------| | Minoxidil (topical) | Proven for both sexes, stops loss, some regrowth; must use long-term | Men & women | | Minoxidil (oral) | Some evidence; more side effects; avoid if heart issues | Men (with caution) | | Finasteride (oral) | Proven for men, effective with long-term use | Men | | Dutasteride (oral) | Slightly stronger, unlicensed, less tested | Specialist only | | Estrogen tincture | Halts loss in women, esp. post-menopause; no regrowth | Women (post-meno) | | Caffeine Shampoo | Promising in lab; not proven in real life | Not effective | | Hair Serums (herbal etc.) | Mostly poor evidence; rare exception for ginseng | Unproven | | Supplements (biotin etc.) | Biotin: nails only, not hair; others not supported | Not for hair growth | | Collagen, brushing hair | No good evidence; could help health but not hair | Not for hair growth |

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Final Verdict

Licensed treatments (minoxidil, finasteride) are effective when used correctly and consistently (“... definitely not marketing bs”). Most shampoos, serums, and supplements lack strong clinical evidence—they may work in theory or on a small scale but cannot be reliably recommended. Commitment and realistic expectations are critical.

“If you’re talking about the licensed drug, they are definitely not marketing bs ... But from there we still always have the final step of clinical evidence and that is often missing.” (Prof. Ralph Pauls, 34:10)

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Listener Takeaways & Tone

• The episode maintains a friendly, evidence-seeking, and occasionally humorous tone (“you might as well eat a good steak”).
• Both listeners leave with concrete options and realistic expectations: long-term use of proven products and skepticism towards unproven “natural” remedies.
• The consensus: “forever” commitment is often necessary, and navigating the “minefield” of products requires evidence and patience.

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Transcript

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[Greg Foot (Host)]

Hello, it's Greg here. You are about to listen to a new episode of the new series of Sliced Bread. Episodes are released on Thursdays wherever you get your podcasts. But if you are in the UK and you cannot wait, you can get the episodes a week early on BBC Sounds. Just go search for Sliced bread hit subscribe to make sure you don't miss an episode and listen first on BBC Sounds. Hello, I'm Greg Foots and welcome to the show that investigates the wonder products promising to make you happier, healthier or greener. Each episode I run one of your suggested wonder products through the evidence mill to find out if it is indeed the best thing since sliced bread or marketing bs. And this week I'm joined by Kimberly Alcock from Grimsby and Ian Baker from London. Hello both.

[Kimberly Alcock (Listener)]

Hello Greg.

[Greg Foot (Host)]

Having two listeners in the studio is a first for the show, but you both got in touch about the same topic from slightly different angles so we wanted to get you both in. Let's start with you Ian. Tell us the wonder product that you would like us to investigate today.

[Ian Baker (Listener)]

Greg. It's one of many. So it's very much about all the hair loss products that I've been buying bombarded with on social media. Having identified that, I've got a bit of a problem with my male pattern baldness.

[Greg Foot (Host)]

What have you seen?

[Ian Baker (Listener)]

So I've seen the sort of conventional medical products. So minoxidil and finasteride are the sort of the standard go to's and then there's a whole raft of natural products, let's call them, that seem to have no scientific base.

[Greg Foot (Host)]

We have had lots and lots of requests to look into products promising to help with male pattern baldness or as it's now often called male pattern hair loss because as we will get into that, hair loss is happening for a while and you potentially go bald. Emilio emailed us on sliced.breadbc.co.uk to say that he'd listened to our previous episode on caffeine shampoo and says that as that went out in 2020. Could we look into the likes of what you've just mentioned there, Ian? Minoxidil and finasteride. Kimberly, can you share with us what you said in your email?

[Kimberly Alcock (Listener)]

Since going through the menopause, I've noticed my hair has started to thin, get dry and even fall out. Like Ian said, I've been bombarded with adverts for hair thickening, shampoos, oils, supplements and I'd just like to know, am I wasting my money trying all these different things?

[Greg Foot (Host)]

Many other women have also got in touch to ask us to investigate hair loss products, including Bryony, who emailed to say she has tried Bello. We've got just one expert for this episode because we are fortunate to be joined by one of the most cited scientists in the follicular field. He's formerly of the University of Manchester, but now teaches at the Miller School of Medicine at the University of Miami, which is where he is calling us from today. Welcome, Professor Ralph Pauls.

[Professor Ralph Pauls (Expert)]

Pleasure to be with you guys.

[Greg Foot (Host)]

Swapping Manchester for Miami. I mean, that's a net gain of sunshine, isn't it, Ralph?

[Professor Ralph Pauls (Expert)]

Yes.

[Greg Foot (Host)]

In broad terms, Ralph, what are the causes of different types of hair loss?

[Professor Ralph Pauls (Expert)]

Well, in very broad terms there, I would say four. One is that you have a hormonal imbalance that you have either too many male hormones impacting on your hair follicles and miniaturizing them, making them smaller or stopping them to grow, or you have a lack of estrogens, which probably is the case in Kimberly's case. Then you can have inflammatory reasons to have hair loss so that your own immune system starts to attack your hair follicles. Then you can get toxic effects on the hair follicle. And perhaps the most famous one is chemotherapy induced hair loss. And then there's some drugs that can cause hair loss. Something as simple as a beta blocker can, in some patients cause hair loss.

[Greg Foot (Host)]

Interesting. And you mentioned hair follicles there. I mean, we've talked quite a bit about hair on sliced bread before, especially in episodes on shampoo and conditioners. But do remind us what hair follicles are, Ralph.

[Professor Ralph Pauls (Expert)]

This is actually one of the most fascinating mini organs that mammals have come up with. Actually the Hair follicle is the little organ that makes the hair shaft, and it sits deep inside your skin. And the fascinating thing about this mini organ is that it runs through a cycle of growth and regression and resting. And it is a disturbance of this so called hair cycle that gives us increased hair shedding.

[Greg Foot (Host)]

Let's talk about what happens to that hair follicle when you've got hormonal hair loss.

[Professor Ralph Pauls (Expert)]

There are two sides to this coin. One side is that the hair follicles don't stay as long as they should in their growth phase, the so called anagen phase that gives you the increased hair shaft shedding per day. And the other side of the coin is that the little mini organ that makes the hair shaft gets progressively miniaturized. A large follicle becomes a tiny little organ that can only make a pigment less fluffy little hair shaft that you can hardly see. So even if you have been balding and you don't see any hair shafts, you still have 100,000 hair follicles on your scalp, but they just make a useless hair shaft that you hardly see.

[Greg Foot (Host)]

And that's both happening in male hair loss and female hair loss.

[Professor Ralph Pauls (Expert)]

Yes, and for the longest time it was thought that female pattern hair loss is pretty much the same as male pattern hair loss, but now we realize it's not. While in male pattern hair loss, it is primarily induced by androgens, male hormones, in female pattern hair loss, it's a mixture of several things. There is on the one end an excessive activity of male hormones, but there's also a relative lack of female hormones, estrogens. And that's why this type of hair loss occurs most frequently in two occasions. One, after having given birth a couple of weeks afterwards, because then the estrogen levels, which are very high during pregnancy, dramatically drop. And the second time when this hair loss gets accelerated and aggravated is during menopause, when the estrogen levels again slowly fall.

[Greg Foot (Host)]

And just taking male pattern hair loss first, you mentioned androgens, male sex hormones the likes of testosterone. What is it that's causing this effect for male pattern hair loss?

[Professor Ralph Pauls (Expert)]

Yes, so testosterone, interestingly enough, is a fairly weak androgen. And for it to cause any major effect on any hair follicle anywhere, it needs to be first transformed into a much more potent androgen that's called dihydrotestosterone, DHT for short. But the fascinating finding is that the response of the hair follicles in different regions of your skin to the same hormone is completely different. So while the beard hair follicles love to be stimulated with these male hormones. And then they produce a very potent growth factor that stimulates hair growth. The ones where you lose your hair follicles during balding. They hate it. And they produce a factor that is hair growth inhibitory. So it's the response of the organization to the same hormone that is diametrically opposed in different region of your body and that is pre programmed in fetal life. So while you develop your skin, it is basically programmed into the hair follicles of a defined region in your skin. How in later life they will respond to stimulation with a hormone.

[Greg Foot (Host)]

Right. So to sum up, for male pattern hair loss, it's this conversion of testosterone into DHT that essentially turns into bad news for hair in men. And it's foetally programmed as to where or how much it's going to affect the hairline.

[Professor Ralph Pauls (Expert)]

Yeah, that's it.

[Greg Foot (Host)]

Female pattern hair loss. There is some contribution of dht, but it's as you were saying earlier, it's more about there being low levels of estrogen.

[Professor Ralph Pauls (Expert)]

You got it. So male hormones do play an important role in female pattern hair loss as well, only they are a combination of a relative deficiency of estrogens and the effect of androgens.

[Greg Foot (Host)]

Nice. Say that over 10% of premenopausal women have some evidence of pattern hair loss. The incidence increases around the time of menopause and may affect up to 56% of women over the age of 70. Kimberly?

[Kimberly Alcock (Listener)]

I started menopause at about 50. So since then, really I've got a few patches of hair. Not many, but at the sides it's starting to go quite thin.

[Greg Foot (Host)]

Ralph, is it the same pattern for female pattern hair loss as it is for male pattern hair loss?

[Professor Ralph Pauls (Expert)]

No, in most patients it's not the same pattern. It's more diffuse in its distribution.

[Greg Foot (Host)]

Okay, so we've got male and female pattern hair loss caused predominantly in these situations by the hormonal factors. Ian, it looks like you've written a novel already. So many notes on that pad. What are you taking from this so far?

[Ian Baker (Listener)]

I'm taking for this. It's much more complex than I thought it was going to be.

[Greg Foot (Host)]

The first thing you asked about was minoxidil, wasn't it?

[Ian Baker (Listener)]

Yeah, that's what I tried.

[Greg Foot (Host)]

Well, let's go to that then. Let's talk about minoxidil. That's the active ingredient inside products such as regain, which goes under the brand name Rogaine in the States. I believe you can also get unbranded minoxidil containing products from various Online pharmacies. The costs look to be pretty similar to the branded products. Regain offer one strength for men, 5% minoxidil in two formulations, either as a foam or a solution. Both are topical products. That is, you apply them onto your scalp twice a day. Regain also offer a range for women in two strengths, either a 5% foam or a 2% solution. What was it that you tried? Which form, Ian?

[Ian Baker (Listener)]

I tried the liquid topical form.

[Greg Foot (Host)]

And how long did you try it for?

[Ian Baker (Listener)]

I tried it for about six months.

[Greg Foot (Host)]

And what led you to stop?

[Ian Baker (Listener)]

I didn't think it was making a great deal of difference, if I'm honest. And it was also then quite expensive.

[Greg Foot (Host)]

Okay. Kimberly, have you seen these products? Have you tried these products?

[Kimberly Alcock (Listener)]

No, I didn't know them. Anything about these.

[Greg Foot (Host)]

I saw you scribble down Minoxidil.

[Kimberly Alcock (Listener)]

I thought that'd be handy to keep a note of that.

[Greg Foot (Host)]

Well, Ralph, lots of questions here. Then I guess the first is, what is minoxidil?

[Professor Ralph Pauls (Expert)]

Yes. So minoxidil is a drug developed against high blood pressure, and when it was taken systemically, so as a tablet, then you had side effects. One of those was hair growth in areas where you didn't find this cosmetically pleasing. On your nose, on your cheeks. So somebody had the smart idea and said, okay, let's make a solution from this and see whether it stimulates hair. Where you do want to stimulate your.

[Greg Foot (Host)]

Hair follicle, and what is the theory for how it works?

[Professor Ralph Pauls (Expert)]

The theory is, so far, not really convincing yet. On the one hand, it increases blood supply because it widens blood vessels. But this has almost been debunked as a. As an explanation for why hair growth is stimulated. And we are still struggling to explain how that really. However, in the laboratory, you can show that minoxidil stimulates a couple of growth factors in the hair follicle that are known to promote hair growth. So what minoxidil actually does to our hair follicles is still not clear enough, but it may do much more than we think and much more than just widening blood vessels and increasing blood supply.

[Greg Foot (Host)]

We saw that some online pharmacies were advertising that the topical solution is effective for around nine in 10 men. They go on to say that this means that there's a 90% chance you will see some improvement in your hair loss within a year while taking the treatment.

[Professor Ralph Pauls (Expert)]

Then you have to be a real optimist.

[Greg Foot (Host)]

What is the evidence then, Ralph? Does it work?

[Professor Ralph Pauls (Expert)]

Well, the evidence in larger studies is that, let's say, more than half of the patients that take it twice daily for at least half a year will see that their hair loss does not further progress. The percentage of patients that actually see hair regrowth that they find cosmetically acceptable, that is much lower. And between what you can measure objectively in a clinical study in terms of hair regrowth and what you, as the affected patient, are satisfied with, this is two different cups of tea, right? So that's why many patients that objectively had a tiny little bit of hair regrowth still say, perhaps, like Ian, that's not enough for me.

[Greg Foot (Host)]

Give us a sense of, is it like a peach fuzz? Is it short? Is it centimeter, Is it dark? Is it light? What can we expect?

[Professor Ralph Pauls (Expert)]

You can get all of that. You can get a kind of peach fuzz, you can get a dark and long peach fuzz, and you can get real hair regrowth. And the percentage that you will experience is not predictable. They can never really predict. Will you be one of the relatively few that have a phenomenal effect of minoxidil, or will you be the majority of people that get a mild effect, or will you be in the minority that gets no effect at all?

[Ian Baker (Listener)]

I'm in the group that my perception was that it wasn't significant. And I'm reassured by Ralph's observations that I'm not going out of my mind with the observations, I suppose.

[Professor Ralph Pauls (Expert)]

Oh, Ian, you're not. But if I may add this one point. So, Ian, the one critical thing is that patients often give up too early. And there are a lot of individual case reports and studies that have shown that even after six months, you can still become a responder to this drug. So the general advice we give in hair clinics is that one should give this agent at least a year, and they will only help you as long as you take them. Because the general problem that has caused the hair loss has not gone away. There is still the problem of androgens inhibiting your hair growth in certain regions of your scalp. So as long as that doesn't go away and you can't attack the problem at its source, you will have to continue using whatever drug you are taking.

[Greg Foot (Host)]

Regain also offers topical products for women as well. Two interesting things to know about this. Firstly, when I compared the ingredients list on the Regain for Men Extra Strength Scalp foam with Regain for Women Extra Strength Scalp Foam, they look to be exactly the same, and notably, they both contain 5% minoxidil. They both cost about 35 pounds. They're in the same size bottle. But the women's Product is supposed to last twice as long because they suggest women use it once a day and men use it twice a day. Ralph, why is the dose different?

[Professor Ralph Pauls (Expert)]

Yeah, this has more historical reasons than real substance behind it. The original study in minoxidil in women was done with a 2% solution. And so I think there's now just this calculation. Oh, women can get away with less. But in. In reality, most physicians recommend that women also use the. The 5%.

[Greg Foot (Host)]

And what is the evidence for the effectiveness of these topical products for women? Is it similar to men where it's kind of a roll of the dice Similar.

[Professor Ralph Pauls (Expert)]

It's similar. The same problems that we discussed for men apply here to women. And the success rate is similar. So if Kimberly is really worried about this hair loss and wants to do something about. Would be really useful to do that. Give it a year of try minoxidil.

[Greg Foot (Host)]

Would you go for that, Kimberly?

[Kimberly Alcock (Listener)]

Committing to a year, I might consider it, yes.

[Greg Foot (Host)]

Let's move on to the other way that you can take minoxidil, which is as a tablet, as Ralph said, originally prescribed for high blood pressure. Online pharmacies sell minoxidil tablets at two and a half milligram doses. They appear to cost around £45 for 60 tablets. That's 75 pence a tablet. Does taking it as a tablet compared to taking it topically have benefits?

[Professor Ralph Pauls (Expert)]

It has the benefit of being easier to handle. Men in general hate to have to massage something twice a day into their scalp. The compliance for doing that is pretty low. And just popping in a tablet while you brush your teeth, that's a different thing. Right. And it's not being used anymore as a blood pressure medication, at least not in most patients, because it has many side effects. And so the most critical question is, do I have more side effect risks if I take it as a tablet than if I take it as a solution? And in general, I would say yes, there are a little bit higher adverse effect risks because the adverse effects that were seen were, for example, cardiac arrhythmias in the high dose. And so with a low dose minoxidil for male pattern balding, that was one of the things that was very carefully looked at. Would I get the same side effects? And luckily that in most patients did not. Yet I would say patients that have cardiac problems should only take minoxidil as a topical agent, not as a tablet.

[Greg Foot (Host)]

Good to know. Yeah, I did see on their list of do not use if you have this low blood pressure heart disease, including abnormal heart rhythms, but you don't have those concerns when it comes to the topical version of this product.

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[Professor Ralph Pauls (Expert)]

Why don't.

[Greg Foot (Host)]

Let's move on to a second drug that's available in tablet form for hair loss. Finasteride. Prices vary a lot on the online pharmacies. A branded product such as Propecia is £40 for a month supply on some sites, 60 on others. Whereas you can get unbranded products for under 15 pounds. Again, the price drops the more you buy. Same first question, Ralph. What is finasteride?

[Professor Ralph Pauls (Expert)]

Finasteride, it's an enzyme inhibitor. It's a drug that blocks the conversion of this weak androgen, testosterone, into the potent androgen DHT and is a very useful technique for inhibiting the progression of male pattern baldness.

[Greg Foot (Host)]

I was interesting to see that the similar sort of percentages on some of these finasteride products. They say it's been proven and clinical studies that demonstrate that it stops hair loss for 90% of men.

[Professor Ralph Pauls (Expert)]

That actually does sound about right, because in the study that I'm aware of, the largest study that was done, it was in the range of 80 to 90%.

[Greg Foot (Host)]

And again, you know, they're saying it may take a year to see some regrowth. Other products say you'll see improvements in three to six months. Is it the same situation as we had with minoxidil?

[Professor Ralph Pauls (Expert)]

Not quite. Because when you use finasteride, you need to wait even longer to see an effect than with minoxidil. So for finasteride, don't even start it if you're not willing to take it a year.

[Greg Foot (Host)]

Okay.

[Professor Ralph Pauls (Expert)]

And it definitely makes sense to combine the two. Normally, what people do is they take the combined 1mg finasteride tablets with the topical minoxidil 5%.

[Greg Foot (Host)]

All the finasteride products I've seen, Ralph, looked to only be talking to men. Is this one strictly only for men? You have described the DHT having, you know, it is there. It is present a smaller effect in female hair loss.

[Professor Ralph Pauls (Expert)]

Yeah, you got that right. But it has been licensed only for use in men because you can imagine if a woman gets pregnant and has a male fetus and you block the conversion of testosterone to dht. This spells bad news for the male fetus. You don't want that. And therefore, for safety reasons, it has been licensed only for men. And yet, where there is no pregnancy risk, for example, for postmenopausal women, it can very well be justified to try finasteride.

[Greg Foot (Host)]

And just before we move to the shampoos, the serums, the supplements that you asked about, Kimberly, I'm going to throw a third drug in here quickly. Dutasteride.

[Professor Ralph Pauls (Expert)]

Yeah. Dutasteride is an even more potent inhibitor of this enzyme that converts testosterone to dhe, does essentially the same thing as finasteride. And there are smaller clinical trials that show that dutasteride is slightly, slightly superior to finasteride in its efficacy. Yet finasteride has the advantage that it has been used for a much, much longer period of time. And if you worry about side effects of any drug you are taking, usually it is advisable to stick with a drug for which we have much longer clinical experience, what side effects it makes. If the effect of the new drug is not dramatically better. Dutasteride is not dramatically better than finasteride.

[Greg Foot (Host)]

I did see one product say, if you have Already tried finasteride 1mg tablets for hair loss and they haven't worked, you may want to consider dutasteride as an unlicensed alternative. So it's admitting it's unlicensed. Should we be advising people to stay clear of these unlicensed products?

[Professor Ralph Pauls (Expert)]

Well, medicine would not have progressed if all doctors had always limited themselves to the use of licensed products. So it's medical practice to also use, in selected cases, unlicensed products. But it's the responsibility of a good doctor to judge whether it's justifiable. So you should not do this by yourself. You should consult a physician for that.

[Greg Foot (Host)]

So dutasteride is slightly stronger than finasteride. I was reading that some men complain about depression and erectile dysfunction when taking it.

[Professor Ralph Pauls (Expert)]

Yeah, this is very hotly debated, both for finasteride and dutasteride. These side effects have been reported in a minority of patients. But you surely all have heard of the placebo effect that you imagine you had a positive effect. But there's also another effect, it's called the nocebo effect, that you imagine a negative effect just because you're expecting it. And so the debate among my colleagues in the field is, is this. Are these side effects that you just mentioned, are they classical nocebo effects or are they real? And that is very Difficult to distinguish. So my advice there is you just give it a try and then if you feel you have these side effects, well, then you discontinue.

[Greg Foot (Host)]

Noted. What about estrogen? You mentioned estrogen earlier, that low levels of estrogen contribute to female hair loss. I was reading about an estrogen tincture. Is that something potentially useful?

[Professor Ralph Pauls (Expert)]

That's something that I like a lot. This has been practiced for decades. But there are no good clinical studies that give you evidence based medicine for the simple reason that no company is interested in testing this and running these studies. Because it's a very cheap hormone and they couldn't patent it. When I was still running hair clinics in Germany, I used this in almost all women with female pattern hair loss. And what you get with that is that you keep the hair follicles longer in their growth phase and you get this effect fairly fast within a couple of weeks. What you do not get with estrogen tinctures is a regrowth of hair. So you can hold the hair loss, you can hold the progression in the vast majority of patients that tried it. You can reduce the daily hair shaft shedding, but you will not promote regrowth of new hair shafts.

[Greg Foot (Host)]

What do you think? Hearing that, Kimberly?

[Kimberly Alcock (Listener)]

Yeah, that might be something to look into. Although I would like to get the hair back that I have lost. That would be ideal.

[Professor Ralph Pauls (Expert)]

I know, I know, Kimberly. So in your case, if you were in my hair clinic, what I would probably do is I would prescribe minoxidil and an estrogen tincture. So with minoxidil we would then hope that you would get some hair regrowth. And with the estrogen tincture you would halt the hair loss or reduce it.

[Kimberly Alcock (Listener)]

Sounds good.

[Greg Foot (Host)]

Well, let's continue with the shampoos and the serums and the supplements, Kimberly, that you've mentioned. What have you tried? What have you seen?

[Kimberly Alcock (Listener)]

I've tried strengthening shampoos, I've tried hair growth serums and one that's says up to 99% less hair on the brush.

[Greg Foot (Host)]

Up to, yeah, yeah.

[Kimberly Alcock (Listener)]

So, yeah, I've tried those and I've also tried collagen supplements and now I'm trying biotin supplements.

[Greg Foot (Host)]

What about caffeine shampoo, have you tried that?

[Kimberly Alcock (Listener)]

I haven't tried that one, no.

[Greg Foot (Host)]

We did a whole episode on caffeine shampoo back in early 2020. Our expert dermatologist, Paul Farren from Brighton and Sussex University Hospitals Trust said this.

[Paul Farren (Dermatologist)]

I think there is good laboratory science behind caffeine and the mechanism on how it could impact on the hair Cycle and therefore it's something of interest. I think at the moment the science of the studies done in humans isn't robust enough for us to have confidence in them. But it's not to throw it out. I think it is something that could be looked at more robustly.

[Greg Foot (Host)]

Ralph, that was early 2020, as Amelia requested on email. Have there been any updates since then?

[Professor Ralph Pauls (Expert)]

Not any major ones. And just for the record, so the science that Paul was talking about here was done by us. So we, we. Yeah, as it so happens. So I was actually very skeptical when I first heard about caffeine containing tinctures until we tried this in our own lab. So we, we took human scalp hair follicles and we organ cultured them in the lab and then we dumped a caffeine on. I was in fact astounded how much it does. But he is perfectly right. Those were hair follicles swimming in a culture dish, not growing on your scalp. And the clinical evidence in good clinical trials that it really does as much as we see in the laboratory, that still needs to be generated. But in principle, caffeine clearly stimulates your hair follicles and makes them also, it's a, it makes them more stress resistant. But let me say this very clearly.

[Greg Foot (Host)]

Yeah.

[Professor Ralph Pauls (Expert)]

No shampoos will give you any predictable hair growth promoting effect. No shampoo for the simple reason that the contact time with your scalp skin is far too low. So most people, when they shampoo their hair, they, they do this in 30, 30 to 90 seconds. That is not enough to get anything deep into your skin. You need an alcoholic tincture that stays on the skin and can slowly sink in.

[Greg Foot (Host)]

Is that essentially a serum? Forgive my naivety, but how does a serum differ?

[Kimberly Alcock (Listener)]

The serum is like an oil when it's in a small bottle with like a pipette. So it is more like a massage oil than a shampoo.

[Greg Foot (Host)]

You pop it on and you leave.

[Kimberly Alcock (Listener)]

It directly onto your scalp and then sort of rub it in for a few seconds and leave it on.

[Professor Ralph Pauls (Expert)]

Yes, exactly. So that can work because in principle that kind of applications of hair growth promoting agents can work because often these sera or alcoholic solutions actually enhance the penetration of the agent into the scalp skin.

[Greg Foot (Host)]

That's really good to know. Let me run through some of the ingredients in some of these serums that you brought to us, Kimberly. I'd just love to get your thoughts on this, Ralph. Fleece flower root extract, poor evidence. Angelica extract, poor evidence. Arbor vitae leaf extract, poor evidence. Panax ginseng extract Depends on what exactly.

[Professor Ralph Pauls (Expert)]

Is in There, there is limited evidence that some of these ginseng extracts can actually promote the production of growth factors in human scalp hair follicles.

[Greg Foot (Host)]

Okay. I also mentioned earlier the product Bello, often marketed as Tri Bellow and on Tribello, we also had a voice note from Bryony.

[BBC Sounds Promo]

Hi, Sliced bread. I don't know about you, but I've been seeing a lot of adverts for hair thinning products in my feed. There's one called Tribello and a raft of others, including shampoos, serums, alongside supplements that claim to turn thinning locks into hair that Rapunzel would be proud of.

[Paul Farren (Dermatologist)]

Love that.

[Greg Foot (Host)]

Right. Bello say they have a hair helper spray plus 46 pounds a bottle. It's supposed to last you one or two months, which they claim reduces hair loss through lowering DHT levels. So this is something we've talked about, Ralph, hair products that are talking about lowering DHT levels, could they be effective?

[Professor Ralph Pauls (Expert)]

Yeah, well, I will not comment on any specific products, but I want to see what is their evidence that they really do that. So what many cosmetic products or food supplements do, they add a component into their product and then they pick out of the literature that for in some essay, in some experimental model, this component has had a certain effect on something. But they haven't shown that their product actually did this. That's not evidence based medicine. Right. You need to show that your product actually does what you claim it does. And if you haven't shown that, well, you are the one who has to generate the evidence.

[Greg Foot (Host)]

This is always the challenge, isn't it, Kimberly? As we've heard with lots of these previous episodes of Sliced Bread. Finally, let's talk about supplements. Ralph, in general, do you think a food supplement could be able to help with hair loss?

[Professor Ralph Pauls (Expert)]

You need to keep in mind that the hair follicles on our scalp are the largest in our body. They have the biggest blood supply. They need to suck up a lot of nutrients in order to produce this long protein fiber, which is the hair folly. So these little mini organs, they are bioengineered by nature to suck up ingredients from the blood, primarily amino acids, other nutrients, oxygen. That means that if you administer the right food supplements, you have at least a chance to impact.

[Greg Foot (Host)]

So let's go through some of these potential ingredients in the supplements. Kimberly, you mentioned biotin earlier.

[Kimberly Alcock (Listener)]

Yes.

[Greg Foot (Host)]

How do you consume that?

[Kimberly Alcock (Listener)]

That's in tablet form.

[Greg Foot (Host)]

Okay. Also known as vitamin B7. Any literature around this, Ralph?

[Professor Ralph Pauls (Expert)]

Yeah, there's lots of literature on that. So what we clearly know, and there is Good clinical evidence that biotin can be very good for your nails. Unfortunately, there is not very good evidence that it is really very good for your hair shaft production. And that surprises us because biotin is needed for many enzymes in your hair follicles to function optimally. But probably biotin is already made in very large quantity by the bacteria in your gut. So most people do not have a deficiency in biotin. So if you have a nail problem, taking biotin, I would say makes perfect sense for hair. I'm not convinced that it does much.

[Kimberly Alcock (Listener)]

No, back to the.

[Professor Ralph Pauls (Expert)]

You cannot have harmed yourself with this. Myotin is a wonderful substance. It probably is good for something in your body, so it wasn't a complete waste.

[Greg Foot (Host)]

Your nails look amazing.

[Kimberly Alcock (Listener)]

Thank you.

[Greg Foot (Host)]

What about vitamin D?

[Professor Ralph Pauls (Expert)]

Yeah, vitamin D is important. It's good for multiple reasons to take vitamin D. But hair growth promotion is probably not the top reason to take it.

[Greg Foot (Host)]

You mentioned collagen earlier. We have talked about collagen quite a few times on previous sliced bread episodes. But while we do have a full follicle expert with us all the way from Miami, I feel I should ask for your one line thought on that when it comes to hair loss.

[Professor Ralph Pauls (Expert)]

So what you really need is sufficient protein supply. And collagen is, of course, a protein. But there is so far no good evidence that taking just collagen as such will do much to promote your hair growth. So you might as well eat a good steak.

[Kimberly Alcock (Listener)]

Yes, I'd rather do that.

[Greg Foot (Host)]

I was gonna say, are you vegetarian or vegan?

[Professor Ralph Pauls (Expert)]

Okay, yeah, for the vegetarians among us. So you eat some nuts and soy, then you're fine as well.

[Greg Foot (Host)]

I've read a lot about brushing hair potentially aiding hair loss. Is that something you've heard of, Kimberly, something you do?

[Kimberly Alcock (Listener)]

I did think about that because when my son was a baby and he rubbed off his hair at the back, I used to brush it with a soft brush just. And I thought I was stimulating the hair growth. It seemed to work, but I don't know if that was. Or it just came back on its own.

[Greg Foot (Host)]

Ralph, any benefits of kind of regular nighttime brushing?

[Professor Ralph Pauls (Expert)]

Yeah, again, there's no good evidence that that really makes much of a difference, but it certainly can't hurt you. You will temporarily increase the blood supply to your scalp if you do that. But this cannot be expected to have a lasting positive effect on hair growth.

[Greg Foot (Host)]

And with that, it's time to ask the final question. The big question, Ralph, do you think that hair loss products are indeed the best thing since sliced bread? Are they sb or are they marketing bs?

[Professor Ralph Pauls (Expert)]

If you're talking about the licensed drug, they are definitely not marketing bs. Finasteride and minoxidil. And indeed there are some cosmetic products and food supplements on the market for whose ingredients there is good laboratory evidence that they should in principle be able to do something positive to hair growth. But from there we still always have the final step of clinical evidence and that is often missing.

[Greg Foot (Host)]

Ian, Kimberly, what are you thinking?

[Ian Baker (Listener)]

I think the combination of systemic finasteride with some topical minoxidil sounds like a sensible way forward. I'm grateful for Ralph for actually giving us some clarity around this whole minefield of. Of, yeah. Snake oil products. Really?

[Kimberly Alcock (Listener)]

The estrogen tincture and the minoxidil together. Yes, those might be a solution.

[Professor Ralph Pauls (Expert)]

And maybe some caffeine. Throw in some caffeine.

[Kimberly Alcock (Listener)]

Yeah. The thing that I've taken from it, I think, is also, if you are doing these things, it's forever. It's not going to be. Your hair is going to come back and that's it. So it's a commitment to think. It's commitment. Yeah.

[Greg Foot (Host)]

Yeah. Ralph, thank you so much. We'll let you get back to your hair follicles.

[Professor Ralph Pauls (Expert)]

Great talking to you guys.

[Greg Foot (Host)]

You too. Thank you so much.

[Kimberly Alcock (Listener)]

Thank you. Bye.

[Professor Ralph Pauls (Expert)]

Bye, Ian. Bye, Kimberly.

[Greg Foot (Host)]

Well, with that, I shall wrap up today's sliced bread. A big thank you to Kimberly, Ian and Ralph for joining me. If you are listening to this and you are thinking, Greg, I have a wonder product I would really like you to investigate. Please do send it over either on email to sliced.breadbbc.co.uk or as a message or a voice note on WhatsApp to 07543-306807. Next time I will be making a list and checking it at least twice. We like to be thorough on this show as I bring you a special festive edition of Sliced Bread. It's our Christmas list. I've gone back over the hundred plus products that we've investigated and picked out five that might just make it under your Christmas tree this year. Don't miss. Sliced Bread is written and presented by me, Greg Foote and this episode was produced by Simon Hoban. Our science AP is Phil Sansom and today's studio manager was Kelly Young. Sliced bread is a BBC Audio north production for BBC Radio 4.

[Alex von Tanselman (Narrator)]

One winter's night in 1974, a crime took place that would obsess the nation.

[Professor Ralph Pauls (Expert)]

We're still looking for Lucan all over the world, Lord.

[Alex von Tanselman (Narrator)]

But Lucan is said to have killed the family nanny and to have attacked his wife before disappearing. Why has this, of all crimes, captured our imagination?

[BBC Sounds Promo]

It's partly that the evidence is so murky.

[Alex von Tanselman (Narrator)]

As I try to get to the bottom of the case, my preconceptions are blown apart.

[BBC Sounds Promo]

I mean, this.

[Alex von Tanselman (Narrator)]

This is a pretty weird stuff to have in a box, isn't it?

[Professor Ralph Pauls (Expert)]

What on earth is this?

[Alex von Tanselman (Narrator)]

For the Lucan obsession with me. Alex von Tanselman from from BBC Radio 4. Listen now on BBC Sounds.

[BBC Announcer]

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