Nettle, the plant for hair regrowth?

Originating from the temperate regions of Europe and Asia, the nettle is a stinging plant belonging to the Urticaceae family. Often known for its stinging properties, it nonetheless contains an extract rich in benefits for the hair within its leaves and is used in the formulation of hair care products under the INCI name Urtica Dioica Leaf Extract. Antioxidant, the nettle can particularly prevent the appearance of white hair. Moreover, the sebum-regulating properties of this natural ingredient make it an ally of oily scalps. As for hair regrowth, the role of the nettle is more subtle.

prevent hair loss than to stimulate its growth. A study has notably shown that the use of a shampoo based on nettle extract and a serum also containing nettle extract for six months helped to prevent and limit hair loss in 120 individuals suffering from androgenetic alopecia and telogen effluvium. At the end of the six months, the researchers noted a 90% decrease in their hair loss , compared to a 40% decrease in participants who received placebo treatments. Let us note once again that this study highlights the benefits of nettle in combating hair loss, not in promoting regrowth.

From a biological perspective, scientists have linked the ability of nettle to prevent hair loss to its inhibitory action on 5-α-reductase. This enzyme notably catalyses the conversion of testosterone into dihydrotestosterone (DHT). This latter increases the expression of interleukin 6 (IL-6), a cytokine that accelerates the transition between the anagen phase, which corresponds to the hair growth phase, and the catagen phase, or resting phase. DHT thus more rapidly induces hair follicles into the telogen phase, or hair shedding phase. The ability of nettle extract to inhibit the activity of 5-α-reductase therefore allows it to protect hair against hormonal changes or genetic predispositions responsible for an increased production of DHT and consequently hair loss.