Provitamin B5: Can It Promote Hair Growth?

The anagen phase, or growth phase, occupies the majority of the hair cycle. During this period, the cells of the hair follicle undergo intense proliferation and cellular differentiation, resulting in the formation of the hair shaft. The subsequent phases, namely the catagen and telogen phases, are characterised by the apoptosis of hair follicle cells, leading to their shrinkage and hair loss. Clinical studies have shown that the abnormal termination of the anagen phase triggers a progressive thinning of hair shafts. Thus, the prolongation of the anagen phase is considered one of the main treatment strategies for hair loss.

Among the molecules potentially having such an action, we find provitamin B5. In vitro studies conducted on dermal papilla cells have indeed shown that this molecule can modulate the hair cycle. After 24 hours of treatment with 50 μM to 5 mM of panthenol, the activity of alkaline phosphatase, a marker of the anagen phase, was significantly increased by 40%. Furthermore, this treatment intensified the activity of vascular endothelial growth factor (VEGF), a key mediator of angiogenesis, by 70%. By triggering the formation of new blood vessels, VEGF supports tissue growth and promotes hair growth. Finally, provitamin B5 has shown that it can decrease the expression of TGF-β1 mRNA, a growth factor that accelerates the entry of follicles into the catagen phase, by 30%.

The effects of panthenol in hair application were subsequently evaluated in clinical trials. Conducted in a double-blind manner with 42 patients suffering from alopecia, a study examined the action of a shampoo aimed at preventing hair loss, containing 0.2% salicylic acid, 0.2% provitamin B5, and 0.1% niacinamide. After 24 weeks, the number of hairs showed a significantly greater increase (17.76%) in the treated group compared to the placebo group. Visual assessment was also significantly more satisfactory in the first group, and no side effects were reported. This study seems to confirm the potential of panthenol to promote hair growth. However, it should be noted that this active ingredient was not used alone in the shampoo: the observed effect could be due to another ingredient or their combination.

Finally, scientists have recently investigated the effectiveness of provitamin B5 injections in combating hair loss. In a recent study, 21 women suffering from hair loss received a weekly injection of 500 mg of panthenol into their scalp. After 2 months of treatment, their satisfaction was evaluated. 28.6% of the patients reported being "very satisfied", 57.1% were "satisfied", and 14.3% were "neither satisfied nor dissatisfied". Although these results are encouraging, the researchers acknowledge that their study has certain limitations due to the small number of participants and the control methodology used (questionnaires only without biopsy).

Although further studies are still needed, provitamin B5 appears to be a promising ingredient for promoting hair growth.