MINNEAPOLIS (WCCO) – Thinning hair, receding hairlines, and bald spots: they’re unwelcome signs of the inevitable for as many as 80 percent of all men.

And for some men, hair loss can be devastating. But now doctors say that big breakthrough may finally be here.

The eyelash growing drug Latisse is being tested for a new use – growing hair. Dermatologist Joyce Davis says it’s very effective as long as the hair follicle, which is the cavity that contains the root of the hair, is still alive.

“Once a follicle has died, it’s very hard to bring it back to life. But once a follicle is still at stages of producing hair, these drugs will help produce longer, darker, thicker hair,” Davis said.

Latisse was originally used to treat glaucoma. Doctors noticed increase lash growth as a side effect, something they also found with the prostate drug Avodart.

“Avodart is actually a wonderful drug for treating hair loss,” Davis said.

The makers of Avodart say that after just six months, they found hair count increased by an average of 96 hairs per 1-inch diameter. Now they’re getting ready to market it specifically for baldness.

Dermatologist Kavita Mariwalla says drugs for treatment of one problem sometimes end up being more successful for the treatment of another.

“A lot of times we end up finding things that we use for other diseases that actually work on hair,” Mariwalla said.

And there are many other developments expected now that doctors know the cause of male pattern baldness, something that’s evaded them until recently.

Too much of the hormone Prostaglandin D2 can shut hair follicles down, preventing hair growth. Researchers and pharmaceutical companies are now racing to develop a bald cure.

“It’s a very exciting finding,” Mariwalla said.

Doctors are also encouraged after discovering Vitamin D helps with hair growth. Scientists are hoping it can coax dormant follicles to grow hair again.