Evidence for Caffeine in hair loss

Will pouring cups of cold coffee over your hair increase hair growth? 

Maybe .... but it would be very messy and you will need many cups of coffee to get the right amount of caffeine!

This article will explore:

• How caffeine works to improve hair growth 
• Caffeine vs Minoxidil - who reigns supreme?
• How long does it take for topically applied caffeine to be absorbed into the hair follicles?

How does caffeine work for hair growth?

Caffeine is thought to improve hair growth by prolonging the anagen (growth phase) of the hair cycle.

The proposed mechanism is by inhibiting the enzyme phosphodiesterase which increases cAMP levels in cells and therefore promotes cell proliferation. To demonstrate this concept, a study conducted by Fischer et al. used hair organ culture model to investigate the effects of testosterone and caffeine on hair follicles.

This in vitro study used scalp biopsy samples from male with androgenic alopecia which were exposed to different concentrations of testosterone and caffeine solutions for a period of 120-192 hours. The hair samples exposed to testosterone had reduced growth and the while the hair follicles exposed to testosterone plus the addition of caffeine in concentrations of 0.001% and 0.005% were found to counteract the suppressive effects of testosterone. The testosterone + caffeine samples had a higher hair shaft elongation seen at 120 h after caffeine administration, compared to the testosterone only group.

Caffeine vs Minoxidil for hair growth

In 2017, Dhurat et al showed that 0.2% caffeine-based topical liquid produced similar results to minoxidil 5% solution in men with androgenetic alopecia using using a frontal and occipital trichogram. Dhurat's randomised controlled study included 210 men with androgenic alopecia for a period of six months. At 6 months, the 5% minoxidil solution group showed a mean improvement in anagen  growth of 11.68% versus the 0.2% caffeine solution group who had an anagen improvement of 10.59%.

Does this mean we should ditch Minoxidil? Certainly not.

Another study showed that combining Minoxidil 2.5% and Caffeine produced better hair growth than caffeine alone. The randomised double blinded study included 60 participants over 150 days. Group one participants applied 1ml of Minoxidil 2.5% + Caffeine topical solution twice daily while group two participants applied 1ml of Minoxidil 2.5% topical solution twice daily. After 150 days, group one participants showed statistically significant better growth.

How long does it take for topically applied caffeine to be absorbed into hair follicles?

A recent study assessed the follicular penetration of caffeine on topical application in a shampoo formulation for 2 min and showed that penetration via hair follicles was faster and higher compared with the interfollicular route. The interfollicular route is the scalp area between each hair follicle. 

What is our take on Caffeine?

There is promising evidence for caffeine for the management of hair loss, however, it should not be used as a single agent. Combining Caffeine with other hair promoting agents such as Minoxidil can significantly improve hair growth.

References

1. Bansal, M et al. Role of Caffeine in the Management of Androgenetic Alopecia. Int J Trichology. 2012 Jul-Sep;4(3):185–186.

2. Dhurat, R et al. An Open-Label Randomized Multicenter Study Assessing the Noninferiority of a Caffeine-Based Topical Liquid 0.2% versus Minoxidil 5% Solution in Male Androgenetic Alopecia. Skin Pharmacol Physiol. 2017 Oct 21;30(6):298–305.

3. Chen, D et al. Anti-hair loss effect of a shampoo containing caffeine and adenosine. Journal of Cosmetic Dermatology. 19 May 2024.