Call it pre-wedding beauty jitters, simply getting older, or having a father who went bald in his twenties (sorry, Dad), but these days I’ve been worrying about hair thinning and hair loss a lot more than I care to admit. And before you ask, yes—my haircare routine is up to par. Am I taking care of my scalp? Check. Supplements? Check. Hair still thinning? Check.
All of this got me wondering about Rogaine—or more specifically, minoxidil, its active ingredient. Then, seeing some millennial-targeted ads for newer versions of the original formula (such as Keeps and Hers) prompted me to investigate. Because before I start using a new product, especially one with such a potent active ingredient, I like to get all the facts. For starters: how does minoxidil work? Do you have to be balding to benefit from it? And are there any negative side effects? We spoke to a slew of experts to find out. Here’s what they had to say.
What is Minoxidil?
Minoxidil is a topical serum developed initially as an oral medication for blood pressure that promotes hair growth, thickness, and strength.
- Type of ingredient: Topical treatment for hair growth
- Main benefits: Encourages growth, strengthens strands, stimulates the hair follicle
- Who should use it: In general, anyone who is concerned about hair loss can use minoxidil. It is not recommended for pregnant individuals.
- How often can you use it: Apply as directed on the packaging to damp hair. You should see results in two to three months with regular use.
- Works well with: Vitamin D
- Don’t use with: Over-the-counter hair dye and other potential irritants
What is Minoxidil and How Does it Work?
A quick Google search will tell you that minoxidil is also an oral medication for blood pressure—which is how it was first discovered to help with hair growth. “Minoxidil was originally developed in the early 1960s as an oral treatment for high blood pressure, a condition for which it is still, albeit rarely, used,” explains Kim D. Edhegard, MD, a Virginia-based dermatologist. “In one of the early trials for the treatment of blood pressure, the curious side effect of hair growth was noted.” After a few decades of research, the FDA approved topical minoxidil to treat male hair loss (and thus, Rogaine was born), and then later, for female hair loss as well.
Interestingly, scientists can’t quite agree on how minoxidil works to promote hair growth. “Possibly, this hair growth occurs because minoxidil causes increased blood flow to the hair by dilating the blood vessels in the scalp,” explains board-certified dermatologist Divya Shokeen. Another hypothesis, supported by 2017 data suggests that minoxidil increases a specific enzyme (called ATP) in the hair follicle, extending its growth phase (scientifically called the anagen phase). It is also thought to enlarge hair follicles that have shrunken due to hormonal changes.
Benefits of Minoxidil for Hair
No matter how minoxidil works, one thing's for certain: It can greatly benefit those with thinning hair and/or hair loss:
- Stimulates hair growth: "Minoxidil is a topical medication that is applied to the scalp to stimulate new hair growth in those experiencing hair loss,” explains Samantha Fisher, MD, a Florida-based dermatologist.
- Increases hair thickness and density: In addition to stimulating hair growth and quelling a receding hairline, “Minoxidil can increase the density and thickness of hair,” says Fisher. In other words, strands grow back fuller and healthier.
- Treats hair disorders: Minoxidil is shown to be effective in promoting hair regrowth and density in patients with Androgenetic alopecia and female pattern hair loss.
Hair Type Considerations
Generally speaking, minoxidil is safe for all hair types, including natural hair, although those with color-treated hair may experience more irritation. Minoxidil may be less effective on certain types of hair loss, such as forms of scarring alopecia that are more common among Black women. Everyone is different, of course, so results vary, but overall, “...hair density will generally begin to stabilize two to three months into treatment, with fewer and fewer hairs being lost each day,” Edhegard says. “This will continue over the treatment period to each person’s maximum.” In order to keep seeing the results, you have to continue treatment.
How to Use Minoxidil for Hair
Unless you are pregnant or trying to become pregnant, minoxidil should be safe for you to use. The OG minoxidil product is Rogaine, and there are versions oriented toward women formulated with two percent and five percent of the ingredient, in both liquid (scalp drops) and foam. Hers offers hair regrowth drops with two percent minoxidil. While both products are very similar, Hers is a tiny bit cheaper and has an overall more pleasant look. Rogaine is more widely available at pharmacies and on Amazon, while Hers must be ordered directly from the brand online.
Directions will vary depending on the product; most serums are topically applied. For a product like Hers, follow these steps:
- Apply about 1 ml of product to the scalp on damp or dry hair
- Do not wash out for at least four hours
- Repeat twice a day
Since hair loss is complex and can be triggered by a number of factors—stress, changes in your hormones, recent illness, vegetarian or low protein diets, and rapid weight loss—Virginia-based dermatologist Brenda Dintiman, MD, advises that if you’re experiencing serious hair loss, you’d be wise to consult a professional. “A board-certified dermatologist can sort out what’s causing your hair loss and combine topical minoxidil with supplements like vitamin D and dietary recommendations to get your hair glossy, growing, and full again," she says.
According to Gretchen Friese, a BosleyMD-certified trichologist, you may experience redness or a little itching when using minoxidil because it increases blood flow to the scalp. However, it's best to see a dermatologist if the irritation doesn't improve.
Be mindful of using the correct strength of minoxidil as well. Friese says that there are different strengths for men and women and it is recommended that men use a 5 percent strength and women use 2 percent.
"The BosleyMD Hair Regrowth Treatment ($45) for Women and Men are great minoxidil products," she says,
Is minoxidil good for hair growth?
Using minoxidil will eventually result in thicker, denser hair—but it will take time to achieve, and you will have to keep up with the treatment to maintain.
Are there any side effects to taking minoxidil?
It is thought that women are more susceptible than men to some side effects of the medication, particularly unwanted hair growth. They may also experience lightheadedness and scalp irritation. “In addition, women may experience facial hair growth as an unwanted side effect at higher potencies,” Fisher says.
Can minoxidil make my hair fall out?
If you do choose to use minoxidil, don’t be alarmed if, at first, your hair appears to be falling out faster than usual. “I warn patients that hair shedding initially is normal, as the minoxidil stimulates the resting hairs to cycle into the growing phase,” Fisher explains. “This shedding resolves as the newer, healthier hairs grow in.”
Do you lose hair if you stop minoxidil?
“One myth that surrounds the use of minoxidil is that it eventually worsens hair loss when stopped,” Edhegard explains. “This is not true; what actually occurs is that the hair will return to the point where it would have been, not back to where it was when treatment started, as untreated hair thinning is a progressive problem.”
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Cleveland Clinic. Minoxidil topical solution or foam.
Cleveland Clinic. Hair loss in women. Updated February 10, 2021.