At some point, probably around middle age, the image staring back at you in the mirror is going to look different. Maybe your forehead will be more prominent than usual, or a circular patch of scalp will suddenly appear smack dab in the middle of your head. Two drugs—finasteride and minoxidil—are FDA-approved to treat this.
By age 50, about half of men and up to 40 percent of women will experience at least some hair loss (1, 2). While bald is all the rage these days—just ask Hollywood celebs like Dwayne “The Rock” Johnson and Terry Crews—the cue ball look might not be your thing. The good news is you can keep your hair, and even regrow some of what you’ve lost, thanks to treatments from your dermatologist or trichologist (a doctor who specializes in treating hair problems).
We wanted to know: Is one better than the other? And will combining the two drugs give you improved results or create a science experiment on your scalp? Here, two experts weigh in on the evidence behind these hair-loss medicines.
About the Experts
Ross Kopelman, D.O., is a Hair Restoration Surgeon practicing at Kopelman Hair Restoration in New York City, New Jersey, and Palm Beach, FL. Michele Green, M.D., is a board-certified Cosmetic Dermatologist practicing in New York City.
The Basics: Minoxidil and Finasteride
Minoxidil
Minoxidil wasn’t created to combat hair loss. It started out in the 1960s as a blood pressure pill (4). Then, in the 1980s, a sharp-eyed Colorado dermatologist named Guinter Kahn noticed something unusual: his patients taking minoxidil to manage hypertension were also sprouting more hair (8).
While that might sound like a win, the high-dose version of minoxidil came with some pretty serious side effects, like heart swelling, low blood pressure, and low platelets (cells that stop you from bleeding when you cut yourself) (3). Fortunately, scientists developed a topical form of minoxidil (known as Rogain, which you can buy over the counter), that delivers hair growth without the scary side effects.
How does minoxidil help you hang onto your hair? That’s a big question mark. “Believe it or not, we don’t actually know for certain how minoxidil works, but we have some ideas,” says Ross Kopelman, D.O., a hair restoration surgeon practicing at Kopelman Hair Restoration in New York, New Jersey, and Florida. “First and foremost, we believe that minoxidil has an impact on vasodilation, which means opening blood vessels to the scalp.” The extra blood carries nutrients like vitamin D and biotin, as well as extra oxygen to nourish hair and help it grow. Minoxidil also lengthens the anagen or “growth” phase of hair growth.
Both the 2 percent and 5 percent strength formulations help stimulate hair regrowth, research shows, but 5 percent strength works better. In a one-year study of 904 men with age-related hair loss, 62 percent had less visible scalp after using 5 percent minoxidil twice a day, and 84 percent had at least some hair regrowth (4).
It’s worth noting that minoxidil doesn’t stop hair loss. “It helps increase the growth of the hair, the thickness of the hair, and how long the hair stays in the growth phase, but it doesn’t prevent hair loss,” says Kopelman. For that, he says, you have to look into finasteride.
Finasteride
Like minoxidil, finasteride wasn’t developed to treat hair loss. It was introduced in the early ’90s to treat benign prostatic hyperplasia (BPH), aka an enlarged prostate (5). Finasteride treats BPH and hair loss in basically the same way: it blocks testosterone from converting to a hormone called dihydrotestosterone (DHT), which can cause both prostate enlargement and hair loss.
How does it cause the latter? “When DHT levels become too high, it can bind to the hair follicles, causing them to weaken, leading to hair loss and a decrease in new hair growth,” says Michele Green, M.D., a board-certified cosmetic dermatologist practicing in New York City.
In a Japanese study of more than 3,100 men with male-pattern baldness, 87 percent saw at least some new hair growth while taking finasteride (6). Finasteride works best for hair loss on top of the scalp.
If one hair-loss drug is good, could two be better? Yes, say our experts. Because these drugs work in different ways, they have a synergistic effect when combined.
“Finasteride is great at keeping the follicle healthy for strong hair growth, while topical minoxidil can keep the hair follicle in the anagen phase for longer,” says Green. “Studies have shown that combining topical minoxidil and oral finasteride gives patients better results than taking either medication alone.”
A 2020 meta-analysis of five clinical trials compared combination therapy with either minoxidil or finasteride alone. Participants who took both drugs had better hair growth, although the authors said the dose of these drugs still needs fine-tuning (7).
Could taking minoxidil and finasteride together boost their side effects too? Minoxidil can irritate the skin on your scalp and make hair grow in places where you don’t want it (basically, don’t rub it on your ears). Finasteride’s side effects include erectile dysfunction, loss of sex drive, low semen count, and breast growth in men (3, 5). While none of these side effects sound like fun, Green stresses that, “These medications are safe to use together.”
Types of Minoxidil and Finasteride
Both these drugs come in topical and oral forms, but most people take finasteride as a pill and use minoxidil topically, says Green.
Topical meds are for people who want to treat their hair loss at the source and minimize side effects. Minoxidil is available over the counter as Rogaine liquid or foam in 2 percent and 5 percent strengths. You apply it to your scalp twice a day (3). Topical finasteride, and combos of minoxidil and finasteride, are also available.
Oral formulations may be a better option if topicals irritate your scalp or you’d rather take a pill than get your hands messy with a foam or liquid. You’ll need a prescription to get them. Finasteride for hair loss is a 1 milligram (mg) tablet you take once a day.
While women can use these hair-loss meds, finasteride is definitely not for women who are pregnant or who could get pregnant. It’s considered a pregnancy category X drug because it is linked to birth defects (5).
Minoxidil is also available in a low-dose (1.25 mg) oral formulation. Though it’s not FDA-approved for treating hair loss, some doctors prescribe it “off-label” for that purpose (8).
The Bottom Line
Watching your hair disappear down the shower drain is no longer inevitable. You can do something to slow hair loss, and even grow back hair you thought was gone for good. Finasteride and/or minoxidil might be part of your hair loss solution.
Remember, before you start on these medicines, everyone responds to them differently. “Some people have dramatic changes, and some people have subtle changes. It really depends,” says Kopelman. A doctor can describe what to expect, and help you decide which treatment is right for you.
