Caffiene and hair growth
Caffiene and hair growth

HOW CAN CAFFEINE HELP YOUR HAIR?

Caffeine prolongs hair growth duration resulting in thicker hair that grows for a longer period of time due to its effect on growth factors local to the hair follicle. Caffeine stimulates the production of  fibroblast growth factor (FGF), insulin-like growth factor 1 (also known as IGF-1) and reduces transforming growth factor β2 (also known as TGF-B).  FGF induces the anagen phase in the hair growth cycle.  IGF-1 increases cell growth and keratin production within the hair fibre and TGF-B instructs the hair to stop growing in preparation to be shed from the scalp.

The impact of caffeine on the hair growth cycle makes it useful in improving the appearance of thin and slow growing hair and can help reduce the severity of telogen effluvium.   Caffeine also inhibits the actions of testosterone within hair follicle cells, reducing the severity of androgenic alopecia.

One study that looked at effective concentrations on female hair follicle, showed that even at very low concentrations, caffeine was able to the length of the hair shaft in less than 24 hours [1].  The success of caffeine preparations reducing hair loss and encouraging hair growth is thought to be based on its ability to work, simultaneously, on two key hair growth-regulatory factors.

THE EFFECT OF TOPICALLY APPLIED CAFFEINE ON HAIR

Caffeine is a central nervous system stimulant that impacts a number of physiological processes.  Caffeine is both fat and water soluble, meaning it’s easily added preparations and can be absorbed through nearly all membranes very easily. Adenosine receptors in the hair follicle trigger the expression of growth factors: FGF, IGF-1 and TGF-B.

Due to its molecular similarity to adenosine, caffeine is able to bind to adenosine receptors and activate them.

Caffeine for hair loss

CAFFEINE AND HAIR LOSS; THE CLINICAL TRIALS

A number of clinical trials show that there is a marked increase in hair growth after topical application of caffeine.  Trials that recreate the increase in IGF-1 have shown a significant increase in hair growth after only one treatment period.  This increase in growth was seen for over 12 days.  The results after 2 days shows that IGF-1 by itself can increase hair growth by around 40% though activity slows after 4-6 days.  This data shows that stimulation of IGF-1 with caffeine would be more effective as a daily topical rather than in a hair loss shampoo that is used once or twice a week.

Hair shaft elongation after treatment with IGF-1

Cumalative elongation after treatment

Data from Research Gate [2].

DO THE TRIALS REFLECT REALITY?

Achieving hair follicle growth under laboratory conditions may not necessary translate to topical application at home.  To assess the absorption of caffeine, a study ivestigated the penetration after a 2-min application of 1% caffeine in a shampoo formulation.  It was found that caffeine penetrated into the stratum corneum and into the hair follicles. Absorption through the hair follicles and relevant caffeine levels in the blood were already found 5 min after topical application.  It was also shown that relatively high levels remained in the blood.

The study artificially blocked some follicles to test determination of the penetration and the absorption of drugs into via the epidermis or the hair follicle.  It was found even blocked hair follicles received a transdermally delivered supply of caffeine (fig 1).

Absorption of 0.1% caffeine by follicles

Absorption of caffeine from a cosmetic product for hair loss.  Caffeine levels in the blood after topical application with and without artificial blocking of the hair follicles.

Data from Skin Pharmacol Physiol

THE FINAL WORD

Caffeine can increase many growth factors responsible for maintaining the hair growth cycle.  Many clinical trials show that at the right concentration level, caffeine can be delivered to open and functioning hair follicles and also to resting hair follicles via transdermal delivery.  For a solid hair loss intervention plan, caffeine should be administered alongside zinc, liposomal peptides and other sulphur donating compounds.

REFERENCES
  1. Fischer, T.W., Herczeg‐Lisztes, E., Funk, W., Zillikens, D., Bíró, T. and Paus, R., 2014. Differential effects of caffeine on hair shaft elongation, matrix and outer root sheath keratinocyte proliferation, and transforming growth factor‐β2/insulin‐like growth factor‐1‐mediated regulation of the hair cycle in male and female human hair follicles in vitro. British Journal of Dermatology, 171(5), pp.1031-1043.
  2. Ahn, S.Y., Pi, L.Q., Hwang, S.T. and Lee, W.S., 2012. Effect of IGF-I on hair growth is related to the anti-apoptotic effect of IGF-I and up-regulation of PDGF-A and PDGF-B. Annals of dermatology, 24(1), p.26.

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