Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 5/14/2021
Minoxidil is a hair loss and hair regrowth treatment that’s widely used to treat male pattern hair baldness. It’s available as a liquid or foam and is applied directly to the areas of your scalp with noticeable hair loss.
Minoxidil is often sold under the brand name Rogaine®. Today, it’s also available as a generic hair loss medication.
If you’re experiencing some of the early signs of baldness, such as thinning hair or a receding hairline, you may have looked into minoxidil as a topical treatment for protecting your existing hair and stimulating regrowth.
As with other hair loss treatments, minoxidil begins working immediately, but can take several months to produce noticeable results.
Below, we’ve explained how minoxidil works as a treatment for hair loss, as well as how long you may need to use minoxidil to see improvements in your hair.
We’ve also listed other science-based hair loss medications and products that you can use at the same time as minoxidil to further prevent hair loss and regrow hair.
Minoxidil works by shortening the telogen (resting) phase of your hair growth cycle and moving your hairs into the anagen (active growth) phase.
To understand this, it’s important to quickly go over the process of how your hair grows, sheds and replaces itself.
Your hair goes through several distinct phases as it grows. Together, these phases are referred to as the hair growth cycle, or hair growing process.
During the anagen phase of the cycle, your hair grows to its full length. Research shows that 85 to 90 percent of your hairs are in this phase at any one time. On average, the anagen phase of the hair growth cycle lasts for two to six years, during which your hair grows continuously.
As your hair grows to its full length, it moves from the anagen phase into the catagen phase, in which the hair detaches from your scalp. Next, the hair enters into the telogen phase, in which the entire hair structure rests for several months.
Finally, the old hair fully detaches and sheds from your scalp, with a new hair growing out from the hair follicle to replace it.
Minoxidil shortens the telogen phase of this cycle, meaning your hairs spend a shorter amount of time at rest. It also lengthens the anagen phase, or growth phase, and stimulates your hairs to enter into this phase earlier than they normally would.
Minoxidil also appears to improve blood flow to your scalp, which may help to supply your hairs with the nutrients they need to grow to their full potential.
These combined effects help to stimulate growth and improve the thickness, density and overall appearance of your hair if you’re prone to male pattern baldness.
Because minoxidil causes your hairs to prematurely enter into the anagen phase of the growth cycle, it may cause your hair to look worse before it looks better.
By this, we mean that you might notice that your hair loss increases during the first few weeks or months of treatment with minoxidil.
This is because your hairs need to rapidly go through the telogen and shedding phases of the hair growth cycle before starting the anagen phase.
When you first begin using minoxidil, you may notice more stray hairs on your pillowcase or in your hairbrush than normal.
This is normal and generally isn’t a reason to panic. Instead, it’s best to keep applying minoxidil like usual. Over the course of several months, the shedding will end and you’ll begin to develop new hair growth.
Yes. Numerous studies have looked at the effects of minoxidil, with almost all showing positive results for men with male pattern baldness.
In a study published in 2004 in the Journal of the American Academy of Dermatology, a group of dermatologists looked at the effects of topical minoxidil 5% on more than 900 men with hair loss caused by androgenetic alopecia (a medical term for male pattern baldness).
At the end of the 12-month study, they found that 62 percent of the men had a small area of skin affected by hair loss than at the beginning of the study. Of the other men, 35.1 percent showed no positive or negative change, while 2.9 percent experienced further hair loss.
Overall, 84.3 percent of the men rated the minoxidil solution as either “very effective,” “effective” or “moderately effective.”
A different study from 2007, which was also published in the Journal of the American Academy of Dermatology, compared the effects of topical minoxidil 5% with a placebo over the course of 16 weeks of treatment.
After 16 weeks, the men who used the 5% minoxidil displayed a statistically significant increase in hair growth compared to those who used the non-therapeutic placebo.
The men in the minoxidil group also showed improvements in a subjective assessment of hair loss condition.
The researchers found that both versions of minoxidil were well-tolerated, but that the stronger 5% solution was more effective at promoting hair regrowth.
In short, existing research shows that minoxidil works well as a treatment option for preventing hair loss and stimulating hair growth.
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Because of minoxidil’s mechanism of action, you won’t experience immediate hair growth after you start using this medication.
Instead, as we mentioned earlier, you may shed slightly more hair than normal during the first few weeks of treatment with minoxidil as your hairs rapidly move through their growth cycle to begin a new anagen phase.
Most research shows that it takes a few months before you’ll notice any improvements in your hair after you start using minoxidil.
For example, the studies featured above -- all of which showed positive outcomes -- looked at the results of minoxidil after at least three months of regular use.
Although results can vary from one person to another, you should generally expect to see some improvement from minoxidil after about three to six months, with more significant results after a full year of treatment.
In the meantime, it’s important to be patient and continue using minoxidil even if you don’t notice any day-to-day change in your hairline.
Although minoxidil is safe and effective for most people, you may experience side effects when you first start using this medication.
Common side effects of minoxidil include scalp irritation, dryness, scaling and itching. It’s best to talk to your healthcare provider if these side effects are severe or don’t go away on their own over time.
If you’re using minoxidil to treat hair loss from male pattern baldness, there are numerous things that you can do to improve your results:
Apply minoxidil properly. Minoxidil is generally an easy medication to use, but certain mistakes can make it less effective and increase your risk of developing side effects. Our detailed guide to applying minoxidil for hair growth explains how you should use this medication, with specific instructions for both the liquid and foam versions of minoxidil.
Use finasteride at the same time. Finasteride is a prescription hair loss medication that works by stopping your body from producing DHT, the hormone that causes male pattern baldness to develop. Minoxidil and finasteride are more effective at treating hair loss when used together than when used separately. We offer both medications together in our Hair Power Pack.
Start treatment as early as possible. Minoxidil and other medications for hair loss work best when they’re started early. Try to begin treatment as soon as you notice the signs of pattern hair loss developing.
Minoxidil starts working immediately, but won’t produce any noticeable results for the first three to six months. After six months, you should start to see some improvement, with "final" results usually visible after approximately one year of continuous usage.
In the meantime, you may notice that your hair shedding gets slightly worse. This is a common, normal effect of minoxidil that will get better with time as your hair enters into the anagen phase of its growth cycle.