Study Weighs In on Hair Growth Remedy

From the WebMD Archives

Nov. 19, 1999 (Atlanta) -- It's always been the big question behind hair loss remedies -- prescription and otherwise -- do they really work?

In the past, that assessment was made by the rather painstaking process of counting hairs. But a new study finds there may be a more reliable way to check for regrowth: weighing the hair. And doing that, researchers have found one hair loss product that has a significant and possibly long-term effect on hair loss -- minoxidil.

The study, which appears in the latest issue of The Journal of the American Academy of Dermatology, was supported by a grant from Pharmacia & Upjohn, makers of the Rogaine brand of minoxidil.

Three groups of men aged 18-40 were assigned to use a minoxidil 2% solution, a 5% solution, or a placebo. A fourth group used no treatment whatsoever. Beginning at week six and continuing every six weeks thereafter, the researchers used a piece of plastic with a hole in the center, laid over the thinning spot, to sort out new growth. The growth was then carefully cut and weighed. This continued for another 90 weeks, at which point all the men stopped using the treatments.

The results prove two things about minoxidil: It regrows hair, and the 5% solution works better than the 2%. In fact, the researchers found a 35% gain in hair, by weight, in the 5% treatment group, and a 25% gain in the 2% group.

The bad news is, as soon as the minoxidil treatments were stopped hair loss accelerated -- and within six months the treated men were about on par with those using a placebo or nothing at all.

And more bad news: The effect of minoxidil apparently dulls over time. The researchers found a slight but steady drop-off in hair weight as the minoxidil treatments continued past a year -- though they still remained well above what was achieved with placebo or no treatment at all.

Still, one clinician says the study brings up a key point often obscured by hair-loss remedy advertising: the importance of volume over number of hairs. "The most important part of this study is that it finally addresses that hair weight is more important than hair content," says Gary Hitzig, MD, the author of Help and Hope for Hair Loss. "The best way of comparing it is like having 130 twigs or 100 trees. They're all trees -- but which is going to give you more volume in the forest?"