In the future, will baldness recede from the lives of men?

A glaucoma eye-droplet may do for hair what Viagra does for many men: help them grow what they once could but currently cannot. A recent paper has scientists eyeing the already approved drug bimatoprost as a new treatment for male-pattern baldness.

Similarly to the discovery of the little blue pill’s, ahem, enhancing effects, bimatoprost’s restorative properties were discovered by accident. Glaucoma patients had fuller, longer and thicker eyelashes as a side effect of using bimatoprost droplets. Naturally, the cosmetic industry took note and in 2008 the FDA approved it for additional use as pharmaceutical mascara. But now scientists have shown that it works for hairs on the head – at least in mice and petri dishes.

Researchers from the U.S. and the U.K. tested whether the drug would work on the scalp, using hair follicles in a lab culture and bald spots on the heads of living mice. Both cases showed that scalp follicles grew hair when treated with bimatoprost. The study also identified that the drug works through hormone receptors in the follicle.

One would think that with the billions of dollars there for the taking, more would be done to understand baldness, with the aim of slowing or reversing it. But for all the pharmaceutical approaches currently available or in development, preventing hair-loss had initially been just a side effect. Rogaine started out as minoxidil, a drug for high blood pressure. Propecia (aka finasteride) and Avodart (aka dutasteride) were first used to treat enlarged prostates.

The bare truth is that we don’t know what causes baldness. We know it’s hereditary, but the evidence that it is passed through the mother is thinning as fast as the hair on your uncle’s head. A study of 1125 balding, Caucasian men shows that a pair of genes can make men seven times more likely to experience hair loss, but the exact mechanism of why hair stops growing is unknown. These genes were not on the X chromosome – which men only get from their mother – but on chromosome 20, of which everyone has two. The leading theory for why people, especially men, lose hair is that follicles have a genetically linked sensitivity to a hormone called dihydrotestosterone. However, this hormone is known to regulate hair growth all over the body, so it still can’t explain why men only lose the hair on their heads.

Who knows if bimatoprost will become a billion dollar bonanza like Viagra. Phase II and III clinical trials will likely still be needed. But if it does pan out, millions of middle-aged men could have one less thing to worry about (stress, ironically, can be a cause of hair loss). Now, if only there were a drug that could fix chronic back pain.