In this myth-busting deep dive into the science of aesthetics, Lisa McMahon and physicist Mike Murphy take laser hair removal out of the ‘magic wand’ category and into reality. Plot twist: the hair isn’t the star of the show, it’s just the messenger.

The duo breaks down the surprisingly complex world of the hair follicle, spills the tea on stem cells and the dermal papilla (DP), and explains why so many treatments shrink hair instead of kicking it out for good. Whether you’re a seasoned pro or just laser-curious, this episode mixes physics, biology, and a few “wait, WHAT?” moments to reveal why timing the follicle’s growth phase is the real secret to long-lasting results.

KEY TAKEAWAYS

The hair shaft acts as a conduit that contains melanin to absorb light energy and convert it into heat, but the actual goal is to dismantle the follicle structure.

For effective permanent removal, the laser must successfully target and destroy the stem cells in the bulge and the dermal papilla (DP* at the base of the bulb.

As a hair follicle grows during the Anagen phase, the bulb descends deeper into the skin (towards the subcutis), making it progressively harder to kill as it gets further from the surface.

If a treatment uses insufficient fluence (energy), it may only partially damage the DP. The follicle then regenerates with fewer cells, resulting in a thinner, lighter hair.

Most hair visible on the surface is in the Catagen or Telogen phase, meaning it lacks a matrix and cannot be effectively treated. The true targets for permanent removal are actually invisible beneath the skin during early-to-mid Anagen.

BEST MOMENTS

"The hair is not the target. The hair is a conduit to essentially dismantle the follicle."

"If you kill all the stem cells in the bulge but you leave behind some DP cells, then the DP can regenerate some stem cells."

"The matrix can have up to five times the concentration of melanin compared to the hair... that makes it a really, really good target for light."

"Catching the follicle at the right time is quite tricky because if you don’t catch it at the right time, the DP might just be too deep."

"Science doesn’t lie; we just keep moving around a bit."

ABOUT THE HOSTS

Mike began his career in medical lasers in 1986 with a physics degree and a post-grad in bioengineering. He helped develop the scar-free removal of tattoos using a Q-Switched Ruby Laser in Glasgow, and the world's first IPL system. Known well in the industry for his hard truths, no BS attitude and logical answers. As the author of three books, articles for medical journals, a well read blog, a Laser Protection Advisor and contributor to the BMLA, Mike is the Laser Guru.

Lisa's claim to laser fame is being Mike's daughter. Growing up with lasers and never avoiding a physics lesson from her Dad, it was natural to enter the industry. Leaving a corporate career with a baby to jump into self employed life came with challenges. Despite that Lisa has been well recognised for her teaching style, practical tips, bringing the compassion to the science, and laser mentoring.

Instagram: @dermalase_lasertraining

https://mikemurphyblog.com

https://www.dermalasetraining.com