If you spend any amount of time on the internet searching for "rogaine hair thinning products" , or anything like it, you're bound to find questions like, "Will Rogaine make my eyebrows grow back faster?" "Does Rogaine help to grow mustaches?" "Can I use Rogaine on my cat?"
There are a lot of misconceptions about Rogaine, beginning with the idea that it works like the hair tonics in the cartoons to immediately turn the user into a hair monster.
The good news is that yes, for most men, Rogaine does work as it says it will. The problem is that most people don't know what Rogaine actually claims to do.
Rogaine's active ingredient is a chempical called Minoxidil Topical Solution, which works to stimulate hair growth -- very slowly. Hair regrowth can take up to four months to begin, and even then the hair grows in colorless and downy at first. It thickens and darkens into the natural hair color with continued use, but the process is not fast or easy. (Notice that this partially answers two of the three questions above, because Rogaine stimulates hair growth, but it doesn't make it grow faster).
Most people who talk about Rogaine seem to think it makes hair grow wherever it's applied. Rogaine's own instructions have a picture of the actual spot where Rogaine is most effective: the vertex, or that bald spot many men get on the top of their head. Rogaine doesn't actually work to cure receding hairlines or frontal baldness.
However, Rogaine can stimulate unwanted hair growth. While you may be able to apply it to a receding hairline forever without achieving results, it may stimulate hair growth on the back or face where it may not be wanted. (This is especially true of Women's Rogaine, which may stimulate hair growth all over the head but can also cause facial hair to grow.)
Finally, most people think that Rogaine will regrow hair and then it will just stay put - balding problem solved! Unfortunately, this isn't the case. Rogaine does stimulate regrowth, but only as long as it's being used. When people stop using it, the regrown hair falls out within about 4 months. A commitment to having hair involves a pretty long commitment to buying and using Rogaine daily, and Rogaine explains that it should become a part of your daily routine.
Rogaine is an effective product, and people who feel strongly about restoring their hair should try it to see if it works for them. The odds are in their favor. But those expecting a quick fix followed by a long life full of flowing hair and no Rogaine application should probably reevaluate. (And please, don't use Rogaine on your cat. If it's dangerous for pregnant women, which it is, it is certainly dangerous for animals.)