Caffiene and hair growth
Caffiene and hair growth


Caffeine (1,3,7-trimethylxanthine) is a plant alkaloid with usefulness as a therapeutic agent for the prevention of hair loss.  Caffeine is both fat and water soluble, meaning it’s easily added to preparations and can be absorbed through nearly all membranes very easily.

When applied to the scalp, caffeine prolongs hair growth duration.  The growth stimulating effect is due to its influence on growth factors that act on the hair follicle and its natural blood vessel dilating action.

One study that looked at effective concentrations on the hair follicle, showed even at very low concentrations, caffeine was able to increase 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.


Topical application of caffeine influences the expression of growth factors that act on the hair follicle.  Growth factors are groups of proteins that stimulate the growth of specific tissues. They play an essential role in promoting cell division and differentiation.  For hair growth, a keratin cell must divide to increase size and then differentiate from a living cell to the hard fibrous material we see emerge from the scalp.  Topically applied caffeine stimulates the production of growth factors such as fibroblast growth factor (also known as FGF) and insulin-like growth factor 1 (also known as IGF-1).

The fibroblast growth factor family are directly involved in the regulation of the hair growth cycle.  Fibroblast growth factor is a crucial regulator of hair growth in the human follicle.  It promotes hair growth by increasing hair follicle size, inducing anagen (growth) phase in telogen (resting hairs) and resisting shift back into telogen meaning thicker hair grows for a longer period.

Insulin-like growth factor 1 is expressed in the dermal papilla, at the base of the hair shaft.  Insulin-like growth factor 1 affects hair follicle remodelling and initiation of the hair growth cycle.  In the presence of Insulin-like growth factor 1: blood vessels dilate allowing a higher level of nutrients to reach the hair follicle, sebaceous gland function is regulated and production of keratin within keratin cells is increased.  Insulin-like growth factor 1 also increases collagen production, providing firmer anchorage for the hair follicle unit.

Adenosine triggers the release of growth factors such as fibroblast growth factor, insulin-like growth factor and inhibits the release of transforming growth factor β2 when bound to adenosine receptors.  Due to its molecular similarity to adenosine, caffeine can bind to adenosine receptors and activate them.

Caffeine for hair loss


Several clinical trials show a marked increase in hair growth after topical application of caffeine.  Trials that recreate the increase in insulin-like growth factor 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

To assess the absorption of caffeine in a topical solution, a study investigated the penetration after a 2-minute application of 1% caffeine in a shampoo formulation.  It was found that caffeine penetrated 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 transdermal supply of caffeine.

Cumalative elongation after treatment

Absorption of 0.1% caffeine by follicles

Data from Research Gate [2] and Skin Pharmacology Physiology.


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 and androgenic alopecia.

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, functioning hair follicles and to resting, blocked hair follicles via transdermal delivery.

  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.