Is it possible to accelerate hair growth?

Genetic, hormonal, and metabolic factors are the main determinants of hair growth rate.

However, certain molecules and environmental conditions can partially modulate this cycle, by extending the growth phase, that is the anagen phase, or by stimulating cellular activity within the follicle. These effects remain moderate but are scientifically supported. Several actives have thus been identified as capable of accelerating hair growth. Bioactive peptides, such as acetyl tetrapeptide-3 and myristoyl pentapeptide-4, have shown notable activity in vitro. When encapsulated in nanoliposomes, their transcutaneous penetration improves, allowing direct action on target cells. A recent study revealed that these nanocomplexes promote proliferation of keratinocytes and dermal papilla cells, while increasing production of vascular endothelial growth factor (VEGF), type III collagen and fibroblast growth factor (bFGF), which support vascularisation and follicle regeneration.

Less technical but studied to the same extent, the caffeine has shown growth-promoting effects on hair follicles in culture. A recent study found that at 20 ppm caffeine extended follicles by an average of 1.16 mm over five days. This is close to the result with minoxidil (1.19 mm) and greater than the control (0.84 mm). In a daily topical application (0.5%), caffeine led to a significant increase in hair density after 24 weeks in 40 participants, with a mean gain of 4.85% versus a non-significant loss of 1.5% in the placebo group. These benefits may stem from mechanisms such as upregulating IGF-1, a promoter of hair growth in follicles, and downregulating TGF-β2, a regulator that opposes hair growth.

Certain plants, such as Malva verticillata, Carthamus tinctorius or Sophora flavescens, have shown relevant effects on the Wnt/β-catenin signalling pathway, the insulin-like growth factor (IGF-1) pathway, and the vascular endothelial growth factor (VEGF) pathway, all directly involved in the anagen phase. These plant extracts appear to promote keratinocyte proliferation and inhibit catagen factors such as transforming growth factor beta-1 (TGF-β1). Their efficacy remains to be confirmed as available studies involve small sample sizes without comparative control groups.

For cases of alopecia or more pronounced hair loss, it is possible to use medico-aesthetic approaches such as PRP (platelet-rich plasma). This technique involves injecting into the scalp a concentrate of platelets derived from the patient’s blood. After blood collection, the sample is centrifuged to isolate plasma rich in platelets and growth factors. These bioactive molecules, such as VEGF or IGF-1, are then injected into hair follicles. The mechanism relies on their ability to reactivate bulge stem cells and dermal papilla cells, extending the anagen phase, enhancing local vascularisation and limiting follicular cell apoptosis, thus creating an environment conducive to hair growth.

Hair growth can be stimulated to some extent. No method accelerates growth rate beyond genetic limits. Some methods can prolong the growth phase, improve density, or delay shedding.

Note : The hair growth methods mentioned above are not exhaustive. Moreover, diet plays a significant role in hair growth. Studies have shown that a balanced diet, rich in vitamins A, D and E, and B-group vitamins such as biotin, minerals including zinc, iron and selenium, omega-3 fatty acids found in oily fish, antioxidants from colourful fruits and vegetables, and proteins, supports healthy hair growth.