For one, it can prolong the hair’s growth phase. While the exact mechanism isn’t entirely understood, “it’s thought to prolong the growth (anagen) phase of the hair cycle, transitioning follicles from the resting (telogen) phase into the growth phase,” says Dr. Shah. That means your hair prioritizes growing over shedding.
It can also bulk up hair follicles. Follicle miniaturization (which happens in male- and female-pattern baldness, or androgenetic alopecia) describes when hormones actually shrink the hair follicles, so the hairs grow thinner and shorter. Minoxidil reverses this, making hair follicles larger again. It also can “increase blood flow around the hair follicles through vasodilation,” says Dr. Shah. “The overall result is that more follicles remain actively growing hair, and some previously thinning hairs become thicker.”
For that reason, minoxidil tends to be most helpful with androgenetic alopecia, which usually looks like gradual thinning at the crown or around the hairline. But it can also benefit others. “In some situations, I recommend it to patients to help support regrowth after a shedding event, provided the underlying cause is also being addressed,” says Dr. Oska. For example, if you’re seeing stress-related shedding after a major life event, you can try minoxidil to help with regrowth—assuming the trigger has been resolved.
The Downsides of Minoxidil for Hair Growth
There aren’t many downsides of minoxidil for hair growth, although it can have some mild side effects like scalp irritation, itchiness, dryness or flaking, redness, and burning or stinging, per Dr. Shah. That’s because “some formulations contain propylene glycol, which can cause irritation,” she explains.
Another drawback? You might notice more shedding when you first start using minoxidil. “This can happen because older hairs are shed as follicles transition into a new growth cycle,” says Dr. Shah. “While it can be concerning, it’s often temporary.”
And finally, it’s possible to see hair growth in areas other than your scalp—but that only really occurs if you repeatedly touch your face (or some other skin) when you’re applying it.
How to Use Minoxidil for Hair Growth
First, start minoxidil as soon as you notice shedding or hair loss, since it works best if you start it before significant follicle miniaturization has happened. “Hair-loss treatments are much better at keeping the hair on your head versus growing new hair,” says Dr. Castilla. “In addition, further into the hair-loss process, hair follicles become less responsive to treatment.” Not only that, but most people will start to see a difference only after four to six months of using it, so the sooner the better.
Also, get ready to make it a permanent part of your routine. “Consistency is the cornerstone of treatment, and patients who benefit most are those willing to use it on a daily basis,” says Dr. Oska. On that note: You only see benefits so long as you use it. So if you’re dealing with hereditary hair loss, which is permanent, then you’ll have to use minoxidil forever to keep your hair from budging.
The Best Minoxidil for Hair Growth
It’s hard to talk about minoxidil without mentioning Rogaine. “The foam is easy to apply, dries relatively quickly, and is often better tolerated by people with sensitive scalps because it typically doesn’t contain propylene glycol,” says Dr. Shah. (Foam formulations in general are often free of propylene glycol, which makes them a good bet.) Plus, adds Dr. Oska, “there is less risk of the product running down the back of the neck or the forehead.” Virtue’s version is free of propylene glycol, making it gentler, but it also pairs minoxidil with the brand’s proprietary protein that helps repair and restore hair.
