Updated on February 4, 2022.
If you’re a man and you’re noticing a classic pattern of a receding hairline and thinning crown hair as you get older, you may be wondering why male-pattern baldness happens to some people. Scientists are working to better understand the cause, but it’s likely related to both your environment and your genes.
Normally, strands of hair grow for a few years, stop for a few months, then fall out. If the hair follicles are exposed to more male hormones, though, the growth cycle gets shorter, strands get thinner, and new growth is delayed.
One key factor in this process is a hormone called dihydrotestosterone (DHT), which along with testosterone is important to sexual development. In adults, though, DHT contributes to hair loss. DHT influences cells, such as those in hair follicles, through the androgen receptor (AR), which determines how sensitive cells are to the sex hormones. There’s a lot of AR in the balding scalp, and certain genetic variations in AR correlate with the tendency to go bald. (You’ve probably noticed that male balding runs in families.)
Though you may think a sparsely covered crown is a sign that you're a stud, "it's an old wives' tale that guys who have premature balding have great libidos," says urologist Steve Kaplan, MD, director of the Men’s Wellness Program at Mount Sinai Health System in New York City.
What can I do about male-pattern baldness?
If you're not distressed by hair loss, there's no reason to treat it. In fact, by age 80, 80 percent of men have at least some male-pattern baldness. On the other hand, if you do want to intervene, keep your expectations realistic. There's no cure. But there are treatments that can help while you continue to take them.
Minoxidil (Rogaine) is a topical solution or foam that you apply directly to the scalp to stimulate the hair follicles. It’s recommended for men under age 40 who have recent hair loss. For many men, minoxidil slows hair loss and stimulates growth. It does not improve a receding hairline, however. You need to use minoxidil for four months to a year before seeing results. When you stop using it, most of the new hair will fall out within a few months.
Finasteride (Propecia) is a pill that blocks the conversion of testosterone to DHT. It can take at least three months to see new hair growth. Because DHT can also cause growth of the prostate gland, finasteride is also used to treat enlarged prostate (also called benign prostatic hyperplasia, or BPH).
Other medication options are spironolactone (Carospir, Aldactone) and oral dutasteride (Avodart). Alternative remedies for hair loss include hairpieces, hair transplants, and plastic surgery procedures, such as scalp reduction.
It's easier to maintain hair than it is to regrow it, so if you think you may be bothered by hair loss as it progresses, treat your thinning hair sooner rather than later.