Rogaine Works

How Does Rogaine Work?

Despite the fact that Rogaine is FDA approved, its exact mode of action remains uncertain. The comfort that comes with an FDA approved drug is product efficacy, i.e. evidence that it works based on scientific trials, and secondly, that it’s safe to use. As to the theory behind how it works, here’s one that appears to have a significant amount of scientific data to support it. I’ve attempted to put it in layman’s language.

Rogaine (minoxidil) was first known to relieve hypertension back when it was released in the early 1970’s. The mechanism by which this product is effective for treating hypertension is by opening intracellular potassium channels. Normally the concentration of potassium ions within cells is higher than the concentration between cells. The end result of potassium channel opening is a cellular outflow of potassium ions. Today these products are called Potassium Channel Openers or PCO’s. Recent work now suggests that PCO’s also influence hair growth. Correlative studies with products like minoxidil, pinacidil, P-1075, cromakalim, nicorandil and several others have demonstrated they can maintain hair growth. Additional studies have shown the positive effects of minoxidil to actually stimulate hair growth with balding stumptail macaque monkeys. In these studies minoxidil, P-1075, cromakalim and RP-49.356 were all evaluated. The drugs were administered topically to defined spots on the balding monkeys once a day for 4 to 5 months. Hair growth was measured monthly by shaving and weighing the hair. Three of the drugs produced a significant increase in hair weight including minoxidil. The product RP-49.356 had no effect. These studies show through correlative evidence that the opening of potassium channels is an important regulatory mechanism for hair growth.

The specific actions of minoxidil and the PCO process appear to have a relaxing effect on smooth muscle. When minoxidil is used, a metabolite called minoxidil sulphate relaxes vascular smooth muscle. The theory follows that this relaxing effect allows dilation of the blood vessels resulting in increased blood flow to the scalp, which in turn stimulates hair growth. Once stimulated, the human hair growth response to minoxidil is very rapid. Hair follicle numbers increase within a few weeks suggesting that minoxidil is acting on the hair cycle to initiate the anagen (or growth stage) in latent follicles.

Minoxidil (2%), used twice daily as a topical treatment has shown to benefit patients with recent balding with areas 10 cm in diameter. Better results are achievable where areas are not completely free of hair. Roughly 32% of patients will have good results and this product may retard androgenic loss in susceptible areas. There is minimal systemic absorption and the side effects are limited to local dermatitis.

The pharmacology of how minoxidil affects hair growth has not attracted the attention it deserves. A better understanding of how PCO’s like minoxidil stimulate hair growth will lead to more effective products in the future.