The Science of Healthy Hair, Hair Loss and How to Regrow Hair
Huberman Lab Podcast Recap
Published:
Duration: 2 hr 50 min
Summary
This episode covers the biology of hair growth and the various factors influencing hair loss, including hormonal, mechanical, and chemical aspects. It provides insights into treatments such as minoxidil, finasteride, and microneedling, emphasizing the importance of combining mechanical and chemical...
What Happened
Andrew Huberman explains that hair growth is regulated by stem cells located in the hair follicle. Each hair has its own stem cell niche, with growth periods varying significantly between scalp hair and eyebrows. Scalp hair can grow for 4 to 8 years, while eyebrows have a much shorter growth period of just a few months.
Hormones, mechanical stress, and chemical treatments can all influence hair loss. Common treatments for hair loss include minoxidil, dutasteride, ketoconazole, microneedling, and hormone-related therapies. The belief that balding patterns are inherited solely from the mother's side is incorrect, though androgen receptors influenced by maternal genes do play a role.
Psychological states can greatly impact hair growth and coloration, and hair loss can contribute to anxiety and depression. Hair consists of a shaft and a root, with the root extending into a bulb where stem cells and melanocytes are located. Sebaceous glands produce sebum, which waterproofs the skin and has antimicrobial properties.
The anagen phase is the growth phase for hair, lasting 2 to 8 years for scalp hair. Dihydrotestosterone (DHT) shortens this phase and lengthens the catagen and telogen phases, leading to hair loss. Minoxidil, initially a hypertension drug, can extend the anagen phase by increasing blood flow to hair follicles, but it can have side effects like dizziness and increased prolactin levels.
Microneedling is a mechanical treatment that uses small needles to stimulate hair growth by causing micro-inflammation and increasing blood flow. It is often combined with treatments like minoxidil and finasteride to be more effective than using either treatment alone. Microneedling can help recover 'dead zones' on the scalp, though the process can take 30 to 50 weeks.
Caffeine is being explored as a treatment for hair regrowth. It acts as a PDE inhibitor and can stimulate IGF1, potentially offsetting hair loss when applied topically. Caffeine ointments should be applied about three times a week and can be as effective as minoxidil without some of the side effects.
Saw palmetto and curcumin can reduce DHT, with saw palmetto being a weak inhibitor of 5 alpha reductase. Finasteride, another inhibitor of this enzyme, can increase hair count by up to 20% and reduce hair loss in 90% of users, but it also carries risks of sexual dysfunction and mood changes. Combination treatments involving both mechanical and chemical stimuli are recommended for the most effective hair regrowth.
Key Insights
- Hair growth is regulated by stem cells in the hair follicle, with scalp hair capable of growing for 4 to 8 years and eyebrow hair for only a few months.
- Approximately 50% of men and women experience noticeable hair loss by age 50, with psychological effects like anxiety and depression often accompanying it.
- Minoxidil and microneedling are effective treatments for hair regrowth, especially when combined. Microneedling creates micro-inflammation that stimulates hair growth.
- Caffeine is emerging as a promising topical treatment for hair regrowth, acting as a PDE inhibitor and stimulating IGF1, potentially without the side effects of minoxidil.