Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 8/25/2022
Minoxidil is a science-based, FDA-approved medication that’s proven to improve hair growth and slow down the hair loss process.
In fact, a one-year study of minoxidil found that 84.3 percent of balding men who were treated using topical minoxidil rated the medication as either “very effective,” “effective” or “moderately effective” for improving hair growth.
Along with finasteride, minoxidil is a mainstay of treating hair loss from androgenetic alopecia, or male pattern baldness.
As a topical medication, minoxidil is available in two different forms. The first is a liquid, while the second is a foam. Both forms of the medication are designed to be applied directly to the areas of your scalp affected by hair loss.
While both forms of minoxidil are effective, there are several differences between the liquid and foam versions of minoxidil that you should be aware of if you’re thinking of using this medication to treat hair loss.
We’ve gone into more detail on these below, as well as the basics of how minoxidil can fit into your hair loss prevention routine.
Minoxidil is a topical medication that’s used to slow down hair loss and stimulate the growth of your hair.
Originally, minoxidil was developed as a medication for treating high blood pressure. During the development process, researchers found that minoxidil caused hypertrichosis, or excessive hair growth.
After its effects on hair growth were identified, minoxidil went onto the market as a treatment for hair loss in the 1980s, with a higher strength version appearing in the early 1990s.
Currently, both the 2% and 5% versions of minoxidil are available over the counter in the United States. In some countries, minoxidil may require a prescription.
Despite its 30+ year history and immense popularity, researchers still aren’t exactly sure of how minoxidil improves hair growth.
Research has shown that minoxidil can improve blood flow when it’s applied topically to certain parts of the body. This improvement in blood flow may increase the supply of nutrients to hair follicles, stimulating growth and improving thickness.
Regardless of precisely how minoxidil works, it’s certainly effective at stimulating the growth of your hair. Research has consistently found that minoxidil improves hair growth in men affected by male pattern baldness, as well as several other forms of hair loss.
Minoxidil comes in two forms. The first is a liquid solution that’s applied to your scalp using a dropper. The second is a foam that comes in a spray bottle.
Research shows that both forms of minoxidil work well for stimulating hair growth and treating hair loss.
In 2016, one study published in the Journal of Drugs in Dermatology compared liquid minoxidil and foam minoxidil head-on. The study concluded that the two versions of the medication had almost identical effects on hair growth:
After 24 weeks of treatment, the minoxidil foam increased hair count by 23.9 ± 2.1 hairs per square centimeter.
After 24 weeks of treatment, the minoxidil liquid (which contained a lower concentration of minoxidil but was applied twice-daily instead of once-daily) increased hair count by 24.2 ± 2.1 hairs per square centimeter.
It’s worth noting that this study was performed on women with androgenetic alopecia, instead of men. However, as minoxidil has similar effects on both sexes, the results would likely be similar in a study of men with male pattern baldness.
Other research has also noted that the liquid and foam versions of minoxidil are both effective at treating hair loss.
In short, both versions of minoxidil are effective, with no research showing that one works better than the other at stimulating hair growth. From an effectiveness standpoint, you should get the same results from either version of this medication.
With this in mind, other factors, such as convenience, could make the liquid or foam version of minoxidil a better choice for you than the other. We’ve covered these below, noting the unique advantages and disadvantages of each type of minoxidil.
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“I’m a 34 year old father of two and have been using Hims for over a year now. My hair is back to what it was in my mid twenties.”
Both forms of minoxidil are convenient to use. Once you’ve applied either version of minoxidil a couple of times, the process of applying it to your scalp and massaging it into your skin will only take a few minutes to complete.
With this said, some minoxidil users claim that the foam version of minoxidil is more convenient than the liquid one.
For example, consumer use studies have found that minoxidil users generally score minoxidil foam higher on its ease of application, quick absorption, lack of dripping and ability to fit into a daily routine.
Anecdotally, some minoxidil users note that the foam version seems to absorb into the skin in less time than the liquid version, reducing oiliness.
Both versions of minoxidil are easy to apply. The liquid version comes with a dropper that you can use to quickly and accurately measure the correct amount of minoxidil, then apply it to the areas of your scalp affected by hair loss.
The foam version is dispensed from the can via a nozzle. This version of minoxidil is dispensed onto your fingers, then applied to your scalp.
There’s no “best” version of minoxidil when it comes to ease of application. Instead, each form of the medication offers different advantages:
Because the liquid version of minoxidil comes with a dropper, some users find that it’s easier to apply to specific areas of the scalp. This may be helpful if you have long hair and need to apply the medication only to specific areas.
Some users find that the foam version of minoxidil is easier to apply to large areas of skin. You might find this version easier to apply if you have short hair or thinning that affects a large percentage of your scalp.
Although minoxidil is a safe and effective medication for most people, it may cause certain side effects. One of the most common side effects of minoxidil is redness and irritation that develops on and around the skin where minoxidil is applied.
Experts think that this side effect may be caused by propylene glycol -- a water-soluble alcohol that’s often used in topical medications.
The liquid version of minoxidil contains propylene glycol. The foam version of minoxidil, on the other hand, doesn’t contain any propylene glycol. In fact, one of the reasons a foam version of minoxidil was developed was to prevent propylene glycol-related side effects.
If you’re prone to irritation, redness or other side effects from minoxidil, you may find that these side effects are less severe with the foam version of this medication.
Minoxidil is highly effective at preventing hair loss, but it needs to be used correctly for optimal results. Make sure to use the tips and techniques listed below to learn how to use minoxidil foam and get the best possible results:
Apply it correctly. Using minoxidil is a simple process, but it’s important to make sure your hair and scalp are prepared first. Our guide to applying minoxidil lists step-by-step instructions that you can use to apply minoxidil liquid or foam properly.
Be consistent. Minoxidil works best when it’s used twice a day. Make sure to use your minoxidil as recommended. If you often forget to use minoxidil, try setting a notification on your phone, keeping it in an obvious place or using a sticky note to remind you.
Use it with finasteride. Minoxidil works well on its own, but research indicates it’s more effective when it’s used with finasteride. While minoxidil stimulates hair growth, finasteride works by blocking the hormone that causes male pattern baldness. Unlike minoxidil, finasteride requires a prescription. We offer both medications as part of our Hair Power Pack.
Be prepared to wait three to six months for results. Minoxidil works, but the results it produces aren’t immediate. In fact, it’s quite common to experience hair shedding in the first few months of minoxidil use as it starts to affect your hair’s growth cycle. After you start using minoxidil, you’ll typically need to wait for three to six months before you see noticeable results. This is also true for other hair loss treatments like finasteride, which often take several months to produce improvements.
The foam and liquid versions of minoxidil are both effective at treating hair loss and stimulating hair growth.
Because the foam version of minoxidil doesn’t contain any propylene glycol, it may be a better choice if you often experience irritation, redness or other side effects from the liquid version of minoxidil.
Beyond this, it’s all down to your personal preferences. If you use minoxidil regularly, consider trying both versions of the medication to see which one works best for you.