The Tamsen Show: The #1 GLP-1 Doctor – What Works, What Doesn’t & What’s Next

Host: Tamsen Fadal
Guest: Dr. Rocio Salas-Whalen, Board-certified Endocrinologist
Date: December 3, 2025

Episode Overview

In this in-depth, listener-driven Q&A, Tamsen Fadal welcomes Dr. Rocio Salas-Whalen, an esteemed endocrinologist and metabolic health specialist, for a myth-busting conversation on GLP-1 medications. Together, they demystify key aspects of GLP-1 drugs (like Ozempic, Wegovy, Mounjaro), their long-term use, safety, who they’re for, how they interact with hormones, their psychological impacts, and what's on the horizon in obesity treatment.

Key Discussion Points & Insights

1. Dr. Salas-Whalen’s New Book: Weightless

• Motivation for the Book
  • Dr. Salas-Whalen shares that her learning came “more than what I learned in medical school or in my training...from hearing my patients coming to me and their stories about obesity and their weight” [04:30].
  • The book is a metaphor for lifting not just physical weight but also "trauma...guilt and shame—so they become lighter...not just physically but mentally, spiritually, emotionally" [05:18].
• Apology to Patients
  • She opens her book with an apology: "We failed them…obesity is not a willpower problem" [07:23–08:09].

2. GLP-1 Medications: What Are They, How Do They Work?

• Mechanism of Action

  • GLP-1 is a hormone produced in the gut; it helps stimulate insulin, regulates hunger, and reduces the brain's reward response to food [11:05–12:37].
  • The drugs “change your behavior—how you view food...you still enjoy your food, but once you're full...you're not thinking about food in between meals” [13:03].

• Real-World Use & Duration

  • Not a “quick fix”—intended for long-term use, especially for those with lifelong or chronic weight issues [09:33].
  • Temporary use may fit isolated, life-event scenarios (e.g., post-surgery, perimenopause-related gain), but for most, long-term support is necessary.

3. Studied Safety and Effectiveness

• Extensive Data
  • “We have data since the early 1980s...clinical experience and data of this medication being safe” [13:27–13:47].
• Notable Quote
  • "They are not new drugs; they not suddenly happen after Ozempic…we've been using them for type 2 diabetes since 2005” [13:30].

4. The Spectrum of GLP-1 Drugs

• Differences Explained
  • Types: Ozempic/Wegovy (semaglutide), Mounjaro/Zepbound (tirzepatide)—think about them like “versions of the iPhone” [14:21].
  • Each new drug is “safer, less side effects, more effective in regards to weight loss” [14:56].

5. How to Get Prescribed Safely

• Who Should Prescribe?
  • Best: Board-certified obesity physicians, then endocrinologists, then primary care [15:20].
  • Emphasis on responsible use: “We’re not chasing a number on the scale...if you only concentrate on the scale, patients may lose muscle, which is more dangerous than fat” [16:26].

Notable Red Flag

“A huge red flag if they're not doing body composition testing...just by going on a scale or your BMI is not telling me what’s happening with muscle, or with bone either.” [17:26, 48:20]

• Practical Guidance
  • Best body composition test is DEXA scan or similar; avoid compounded or non-pharmacy sources for drug safety [17:31, 18:09].
  • “Nobody should be paying the $1,100 to $1,200 per month...there are manufacturer coupons, government deals making access easier” [19:06].

6. Next-generation and Oral GLP-1s

• New Drugs Coming
  • Triple agonist “Retatrutide” due in 2026: “significantly more weight loss than we've seen so far” [25:18].
  • Oral GLP-1s (oral semaglutide) and monthly injections are in late-stage trials, adding flexibility especially for kids and teens [26:46].

7. Dosing, Microdosing & Body Composition

• Dosing Nuances
  • “For semaglutide, the first dose is more about tolerating higher doses than seeing weight loss” [27:15].
  • Microdosing—using subtherapeutic doses—“won't give you the desired clinical results” [28:23].

8. Lifestyle and Diet

• Essential to Change Diet
  • “It won’t work the same if you keep eating the same...you’ll feel terrible...lose muscle mass, lower metabolism” [30:45].
  • "Muscle is one of the most important organs...anti-inflammatory...if you lose muscle, you lose that effect" [30:45–31:34].

9. Inflammation & Comorbidities

• Anti-Inflammatory Benefits
  • “Patients say within the first week they feel less inflamed...because you’re eating half of what you used to and fewer pro-inflammatory foods” [33:06].
  • GLP-1s are not substitutes for NSAIDs but can reduce chronic inflammation via fat loss [33:06].

10. Contraindications and Special Populations

• When to Avoid GLP-1s
  • “Medullary thyroid carcinoma, MEN (multiple endocrine neoplasia) syndromes, anorexia nervosa” are key contraindications [34:17].
• Perimenopause and Menopause
  • “No, it’s not cheating to use GLP-1s...we shame patients for everything...patients deserve a break” [34:52].
  • “Hormone replacement therapy does not interact negatively or positively—but women on HRT may lose more weight due to better sleep and mood” [36:10].

11. GLP-1s & Specific Conditions

• Hashimoto’s/Thyroid Disease: No direct effect, but lowering inflammation may help [37:09].
• PCOS and Fertility: “GLP-1s regulate insulin, decrease visceral fat, and may improve symptoms” [39:46].
• Pregnancy Planning: Preconception use is encouraged for breaking generational obesity cycles; discontinue upon pregnancy [40:15–41:46].
• IBS/GI Disorders: With proper supervision, IBS may improve due to reduced inflammation; improper dosing can worsen symptoms [38:17].

12. Maximizing Effect & Combating Side Effects

• Muscle Preservation
  • “The patient’s biggest homework is maintaining their muscle mass” [25:03].
  • Key: Increase protein and fiber in diet, hydrate, and exercise (especially resistance training) [48:49].
• Combating Side Effects
  • “Start at the lowest dose; do not titrate up until you are symptom-free (no nausea, no bathroom issues)” [46:15].
  • “If you overeat past fullness, you’ll have nausea or vomiting” [46:15].
• Preventing Hair and Bone Loss & ‘Ozempic Face’
  • “Slow weight loss and enough protein prevents muscle, bone, hair, and skin loss” [49:44].

13. Mental and Emotional Impact

• The Mind Needs to Catch Up
  • “The weight loss happens faster than the psyche catches up…many patients don’t know how to see themselves in that new weight…some struggle with society’s different treatment or with relationship changes after weight loss” [53:55].
  • The book addresses “the aftermath—helping patients with the psychological, social, cultural aspects of weight loss” [55:47, 56:13].

Memorable Quotes & Moments

• On Judgment and Shame:
  “We shame patients for gaining weight, we shame patients for not losing weight on their own, and now we’re going to shame them for using a treatment? They deserve a break.” — Dr. Salas-Whalen [02:31, 35:06]
• On the Science of GLP-1s:
  “They are not new drugs...we've been using them since the early 1980s.” — Dr. Salas-Whalen [13:47]
• On Long-Term Therapy:
  “These are supposed to be long-term drugs…chronic disease, we don't cure, we control.” — Dr. Salas-Whalen [08:30]
• On Muscle and Bone Loss Prevention:
  “No matter what, have half a pound to one pound of weight loss per week. Any faster, you're losing muscle.” — Dr. Salas-Whalen [50:49]
• On the Holistic Impact of Weight Loss:
  “My patients…they lose trauma, years—decades—of guilt and shame…they become lighter in every way.” — Dr. Salas-Whalen [05:18]

Important Timestamps

• GLP-1 History & Safety: [01:46], [13:27–13:47]
• Book Weightless: Purpose & Apology: [04:16–05:58], [07:17]
• Mechanisms of Action: [11:05–12:37]
• Responsible Prescribing and Red Flags: [15:20–17:31]
• Body Composition Importance: [17:26], [48:20]
• Dosing and Microdosing Explained: [27:15], [28:23]
• Upcoming GLP-1 Innovations: [25:14], [26:42]
• GLP-1s, Menopause, & HRT: [36:06]
• Psychological Impact: [53:55–55:47]

Takeaways for Listeners

• GLP-1s have decades of safety data and are not a “fad”; they’re here to stay for chronic obesity and metabolic health.
• Effective, safe weight loss with GLP-1s demands muscle mass preservation, gradual titration, and real dietary adjustments.
• Mental health support is crucial alongside physical treatment—the book addresses this under-discussed aftermath.
• Shame and stigma hinder progress; using scientifically-proven medicine for chronic weight issues is “not cheating.”
• Always seek responsible medical supervision: Board-certified obesity doctors or endocrinologists are best; avoid compounded drugs and quick, unmonitored weight loss routes.
• Weightless by Dr. Salas-Whalen is positioned both as a patient guide and a clinical reference, aiming to empower, inform, and bridge existing gaps in care and understanding.

For more:
Dr. Rocio Salas-Whalen’s new book Weightless releases December 30th, serving as a comprehensive, supportive guide for both patients and healthcare providers navigating GLP-1 therapy. Links and resources are available in the show notes.

Connect & Learn More:
Follow @thetamsenshow for updates. Keep submitting questions for future episodes!