Researchers are zeroing in on a new potential cause of male pattern baldness, and their discovery may pave the way toward more effective and targeted treatments.

Male pattern baldness affects 80% of men younger than age 70. It occurs when hair follicles shrink, and grow tiny hairs that are only viable for short periods of time.

According to the study, bald men tend to have an abnormal amount of a protein called prostaglandin D2 on their scalps. This protein and its derivatives block hair growth.

The findings appear in Science Translational Medicine.

“We have really identified a factor that is way out of whack by actually studying the disorder,” says George Cotsarelis, MD. He is a chair and professor of dermatology at the Perelman School of Medicine at the University of Pennsylvania. “If you look at all the treatments for male pattern baldness, they were all discovered through [chance].”

For example, one of the current treatments for baldness, minoxidil (most commonly known as Rogaine), was originally developed as a treatment for high blood pressure.

This time, researchers got to the root of the problem. “We looked directly at men who were balding and found an abundance of these proteins,” he says.

New Hair Loss Treatments Being Developed

Drugs that inhibit the action of prostaglandin D2 should delay male pattern baldness. “This should work in all men who have male pattern baldness,” Cotsarelis says. The new findings are likely to apply to women, too.

Some companies are already developing such compounds, in one case for asthma. "It shouldn't take too long," he says.

Neil Sadick, MD, is a New York City dermatologist and clinical professor of dermatology at Weill Cornell Medical College. “This is very interesting and certainly we are looking for new targets,” he says.

As it stands, the only treatments for male pattern baldness are:

Minoxidil (Rogaine). A liquid or foam that is applied to the scalp to slow the progression of hair loss and stimulate some hair regrowth.

Propecia. A prescription pill, originally developed to treat enlarged prostate glands, that is part of a class of medications called 5-alpha reductase inhibitors. They block the conversion of the male hormone testosterone into dihydrotestosterone (DHT), a hormone that shrinks hair follicles.

Hair transplants .

Low-energy lasers that may stimulate hair growth.

“We need new treatments, as the available ones are OK, but they are not great,” Sadick tells WebMD. “If we have something that acts on a different pathway, it could be more effective.”

Jeffrey Epstein, MD, says the researchers may be on to something. He is the director of the Foundation for Hair Restoration in Miami and New York City.

“I think there is a lot of credibility for this type of research,” he says. Prostaglandin D2 may well be an important source of hair loss.

“Is this promising? Of course. Anything that can treat male pattern hair loss at the cellular level is exciting,” Epstein says. “To date, this is the most specific way we have seen to inhibit hair loss.”

But any treatment based on these findings is likely still a few years away, he says.

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