Reviewed by Kristin Hall, FNP
Written by Our Editorial Team
When an unusual amount of hair falls out in the shower, it can be alarming. While some hair loss is normal, there’s a difference between daily shedding and a rat-sized clump that takes over your hairbrush.
Hair loss in women is a stigmatized topic, and there’s a double standard in how it’s viewed. Thinning locks may trigger embarrassment when it happens to women — especially when it appears seemingly out of nowhere.
Still, only one medication for female pattern hair loss (FPHL) exists that’s been approved by the U.S. Food and Drug Administration (FDA): topical minoxidil.
Minoxidil is the active ingredient in Rogaine®, the brand-name poster child of hair loss products. It’s been extensively studied with good results in women.
Before we go any further, a PSA: Your hair doesn’t define you as a woman. Just as blonde turns gray, it’s okay to embrace changes in your hair and rewrite the narrative around female beauty standards. It’s also okay to pursue treatment for hair loss if that’s what you want to do.
If you’re considering trying minoxidil on for size, we’re not surprised — it’s safe and effective for the overwhelming majority of people who use it! But like most medications, it’s not perfect and does come with a risk of certain side effects.
Below, we’ll talk about the different types of minoxidil for women and, more importantly, what side effects you might experience when using each.
The OG form of minoxidil is an oral medication first approved to manage high blood pressure. So how did we get from blood pressure to hair loss?
Minoxidil acts as a vasodilator, opening up your blood vessels and improving blood flow. This brings oxygen and nutrients to your hair follicles to help kick dormant hair into the anagen growth phase.
While minoxidil’s exact mechanism of action is still not completely understood, many researchers believe this theory is mostly accurate.
Like some of the greatest medical breakthroughs, the realization that minoxidil could help hair loss was an accident. Shortly after it was approved, people using it for hypertension also grew excess hair as a “side effect.” That must have been confusing, eh?
Some more research and — voila! — a multi-purpose medication was born. Today, minoxidil is a go-to treatment for hair loss and receding hairlines and comes in several forms.
Other treatment options for hair loss exist. But there are limited studies in women, and several have potentially significant side effects — we’re looking at you, topical finasteride!
If you’re interested in trying minoxidil for FPHL, the first step is to understand the different types and how they’re used.
The FDA-approved topical form of minoxidil is applied directly to your hair and scalp. It comes in the form of minoxidil drops, foam and shampoos.
One of the biggest selling points of topical minoxidil is that it can be purchased over the counter without a prescription. For best results, it should be applied at a dosage of 1 milliliter (mL) twice daily for at least 12 months.
Minoxidil solution for women is available as a 2% liquid and a 5% liquid or foam. The percentage indicates how much minoxidil is in it. Whether minoxidil 2% versus 5% is better depends on the person, but both can be effective for hair loss in women.
The tablet form of minoxidil was FDA-approved in the ’70s to treat high blood pressure.
Does minoxidil work for hair loss? While it’s not approved to treat hair loss in women, some healthcare professionals prescribe low doses off-label for this purpose.
Off-label use means a drug has been approved by the FDA for a specific use, but your provider has determined it medically appropriate for another purpose.
Perhaps there’s no FDA-approved drug available for your condition, or maybe the approved drug (or approved form of the drug) hasn’t worked for you. In that case, a healthcare provider may prescribe something off-label.
The finasteride pill is an FDA-approved treatment for male hair loss only. But in spray form, women — postmenopausal women, particularly — can use it for hair loss, too.
Finasteride negates the effects of dihydrotestosterone (DHT), a testosterone-derived hormone that can weaken hair follicles.
The combination of minoxidil and finasteride in a prescription spray offers a mess-free option for women who don’t want to take a pill or use another topical product. Finasteride prevents further hair loss, while minoxidil promotes new hair growth.
A 2020 study of 119 women found that a topical combination of finasteride 0.5% and minoxidil 2% is a promising treatment option for postmenopausal female pattern hair loss. This combination was more effective than a mixture of minoxidil 2% with the steroid 17α-estradiol, even at the one-year follow-up.
Minoxidil and finasteride spray is designed for daily use. Just prime the sprayer by holding it upright and pumping it five times. Then apply the prescribed amount to areas affected by hair loss.
When you decide to use minoxidil, the hope is that it’ll prevent further hair loss — and promote hair regrowth.
But like all medications, minoxidil also poses potential side effects to the user. And adverse effects can vary depending on the form you’re using.
We should also note that hair loss will likely continue once you stop using it.
Topical minoxidil goes directly on your scalp, so any reactions will most likely be localized to where it touches.
More common side effects of Rogaine for women include:
Scalp irritation and itchiness
Slight burning sensation
Minoxidil foams and liquids may contain ingredients like alcohol and propylene glycol to help dissolve minoxidil for better absorption. So, even if you’re not sensitive to minoxidil, you may experience a skin reaction if you’re sensitive to these other substances.
You might be antsy to get minoxidil out of the bottle and onto your head. But just as you’re supposed to test a stain stick on an old shirt before making it your go-to coffee remover, it’s smart to do a minoxidil patch test first.
For most women, skin reactions triggered by topical minoxidil are mild and go away on their own. Still, it’s always best to talk to your healthcare provider if you experience anything strange.
Though less common, other topical minoxidil side effects may include:
Temporary increased hair loss or hair shedding
Unwanted hair growth on areas of the face or body, called hypertrichosis
Of course, these could be triggered by other things, like stress, hormones or personal care products. Tell your healthcare provider if you develop any new symptoms.
While topical minoxidil is FDA-approved for the treatment of hair loss, oral minoxidil isn’t. This means providers may prescribe oral minoxidil off-label to treat hair loss.
It’s extremely important to follow your healthcare provider’s treatment plan and recommendations regarding oral minoxidil. The safety evidence for this purpose is mostly based on low doses given to healthy women who experienced adverse reactions to topical minoxidil.
For example, one 2021 multicenter study of 1,404 patients found that low-dose oral minoxidil had a good safety profile when used for male and female hair loss, with fewer than 2 percent of participants dropping out due to adverse effects. The average low dose used was 1.63 milligrams per day, used for eight months.
Still, there can be serious side effects if it’s not used as prescribed. Some side effects of oral minoxidil include:
Hypertrichosis, which affects approximately one-fifth of people who use oral minoxidil
Fast heart rate
Difficulty falling or staying asleep
Oral minoxidil may also lead to an increase in hair shedding when you first start it. But don’t panic — this is an expected side effect, as it triggers beneficial hair cycling.
A 2022 review of 32 articles evaluated whether topical finasteride is safe and effective for hair loss. In one study, a seven-day treatment of twice-daily finasteride 0.25% topical solution was found to be equally effective as a once-daily finasteride 1-milligram oral tablet.
The authors concluded that using finasteride topically, such as in a combination spray, reduces DHT in the scalp and blood. This form also reduces the risk of whole-body side effects like sexual dysfunction. However, it’s uncertain how many people were included in this study and whether participants included both males and females.
Regardless, the most common side effects of topical minoxidil and finasteride sprays appear to be related to where it’s applied, such as:
A burning sensation
Contact dermatitis, a non-contagious skin inflammation that may present as itchiness, rash, bumps, swelling or small blisters
Additionally, finasteride is classified as a pregnancy category X drug. This means it shouldn’t be used by pregnant women or those planning to become pregnant.
Animal studies have found that finasteride can lead to abnormally developed genitals in male fetuses. Breastfeeding women should also avoid it, as the medication may be transferred through breast milk.
Finally, follow your provider’s dosing instructions. Using more topical finasteride and minoxidil spray than directed will not result in more hair growth or less hair loss.
Even women who rock a shaved head with confidence would rather not be faced with unintentional hair loss. The ability to decide what to do with our hair is one of the fun parts of being a woman. And uncontrollable hair thinning is likely not your idea of fun.
If you don’t have an underlying medical condition behind your hair loss and are considering minoxidil, remember this:
Topical minoxidil is the gold standard. Rogaine (brand-name minoxidil) has been extensively studied and used with success in women struggling with hair loss for many years.
It may have side effects. Like any medication, topical minoxidil for women poses potential risks, though most are localized and temporary. If you’re unable to use minoxidil, there may be other hair loss treatments to consider.
Your healthcare provider can help. Even if you’re not looking for a prescription, it’s helpful to talk to your provider about new hair loss. They can offer medical advice and recommendations to help you feel your best.
You are beautiful. Christina Aguilera sang it once, and we’ll say it louder for the ladies in the back. You are beautiful! Hair loss doesn’t make you any less of a woman. And whether you choose to fully embrace the change or seek treatment, there’s no right or wrong answer.
Ready to take a step toward healthier, happier hair? Take our free hair quiz to see what options may work for your needs.
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