Foam vs. Liquid vs. Oral Minoxidil

A torso of a man holding up a glass of water and minoxidil pill

Minoxidil was the very first medication to be approved by the Food and Drug Administration as a hair loss treatment. But since this drug was first developed, a variety of different formulations have been created. You can now buy several concentrations and types of topical minoxidil online, in local pharmacies, and even some supermarkets – while different types of oral minoxidil are available with a prescription and are being tested in clinical trials. (1) 

Is Minoxidil FDA-Approved?

Minoxidil is an FDA-approved medication that both men and women can use. When used as a hair loss treatment, this drug is approved as both a liquid and a foam. (1)

However, you should know that only concentrations of 2 percent and 5 percent are approved for the treatment of androgenic alopecia (commonly known as pattern hair loss). These topical medications are not FDA-approved for any other type of hair loss, but are often used off-label to treat hair issues like telogen effluvium, alopecia areata, and scarring alopecias. (1)

You may occasionally see other types of topical minoxidil sold, particularly through online websites. Be aware that other formulations of minoxidil – like minoxidil shampoo and minoxidil lotion – are not FDA-approved, even if they’re sold in concentrations of 2 and 5 percent. And similarly, other concentrations of minoxidil (which can range from as little as 1 percent to as much as 15 percent), are also not approved as hair loss treatments, even when they’re created as liquids or foams. 

It’s usually best to stay away from these unapproved concentrations and formulations. Higher concentrations can cause an increased risk of side effects, while lower concentrations and alternative formulations may not work at all. (10-12)

Minoxidil is also approved as an oral medication – but not for hair loss. Minoxidil in oral form is FDA-approved as a blood pressure reducer. These days, it’s mainly prescribed to people with severe hypertension (high blood pressure) that can’t be resolved after taking other similar drugs. (1,2) However, research is currently exploring the use of different doses and formulations of oral minoxidil as hair loss treatments.

Can You Use Oral Minoxidil for Hair Loss?

Two types of oral minoxidil are currently being explored as hair loss treatments: minoxidil pills and sublingual minoxidil. Minoxidil pills aren’t new – this type of oral minoxidil was the first formulation of minoxidil to ever be developed. Sublingual minoxidil, on the other hand, has only been around since 2017. (7)

Oral minoxidil was first created in the 1970s as a blood pressure reducer. It was only explored as a hair loss treatment after 20 percent of patients started experiencing unusual, excessive hair growth. (1) This side effect, known as hypertrichosis, has been one of the main deterrents for the use of oral minoxidil pills as a hair loss treatment. When people start using a hair loss treatment, they expect more hair to grow on their heads – not on their faces, chests, or other random body parts.

Oral minoxidil for high blood pressure is usually taken in doses ranging from 5 milligrams to 40 milligrams per day. (2) In contrast, oral minoxidil for hair loss is taken in much smaller doses, usually ranging from 0.25 mg to 2.5 mg per day. (1) However, the safety and efficacy of doses as high as 5 milligrams per day are also being explored in clinical trials. (3)

Sublingual vs. Oral Minoxidil

Sublingual minoxidil is technically a type of oral minoxidil, as it’s still taken via your mouth. But unlike oral minoxidil pills, sublingual minoxidil pills essentially dissolve under your tongue.

Taking minoxidil sublingually allows the drug to bypass the liver. Preventing the liver from metabolizing minoxidil helps increase the medication’s bioavailability and lessen the amount of time it circulates in the body, which in turn can help reduce the drug’s side effects. (7,8)

Besides that, sublingual minoxidil is pretty similar to oral minoxidil. It’s currently being researched for both male and female pattern hair loss in daily doses ranging between 0.45 and 4.05 milligrams. (7,8)

Is Oral Minoxidil for Hair Loss Effective?

Both oral minoxidil pills and sublingual minoxidil seem to be effective at treating pattern hair loss. Both can improve hair density at the front and top of the head. This is different from minoxidil foam and liquid, which are meant to be applied to the crown of the head and usually don’t have a major impact on frontal hair growth. (5,8)

That being said, both oral and sublingual minoxidil are both still less effective at restoring frontal hair growth compared to hair growth at the crown. After 6 months of taking 0.45 milligram daily doses of sublingual minoxidil, 45 percent of participants had improved frontal hair growth, while 55 percent had improved hair growth at the top of the head. (8)

The same study showed that as the dose increased, more people had improved hair growth at the top of the head, though hair growth did not necessarily improve at the front of their scalps. 50 percent of participants taking a 1.35-milligram daily dose had improved vertex hair growth, while only 17 percent experienced improved frontal hair growth. And 67 percent of participants taking a 4.05-milligram daily dose saw improved hair growth at both the top and front of their heads. (8)

In contrast, an efficacy and safety study found that 5-milligram oral minoxidil pills significantly increased total hair count at the top of the head by 19.23% after 6 months of treatment. Hair growth at the front of the head also improved significantly, but less than at the crown. (5)

While these results are all positive, oral minoxidil seems to produce substantially less hair growth than sublingual minoxidil — even when sublingual minoxidil is taken at lower doses. This seems to be the case long term, too, since the total improvement in hair growth attributed to oral minoxidil pills has been reported as just 12 percent after 6 months of daily use. (5,9)

Oral Minoxidil Side Effects

The side effects of oral minoxidil include issues like hypertrichosis, swelling of the lower legs, ankles, and feet, hair shedding, and cardiovascular changes. The higher the dose of oral minoxidil, the more likely it is that users will experience side effects. (1,3-6)

An open-label prospective study that explored the use of 5 milligram daily doses of oral minoxidil found that 93 percent of patients experienced hypertrichosis. Additionally, 10 percent of the study’s participants experienced swelling of the feet and ankles. (3) 

Another safety and efficacy study exploring 5 milligram daily doses of oral minoxidil in men reported very similar side effects. In this study, 93 percent of patients experienced hypertrichosis and 10 percent experienced feet and ankle swelling. However, 10 percent of this study’s participants also experienced changes to their heart rhythms – which the other study did not detect. (5)

As the dose of oral minoxidil for hair loss is lowered, so do its side effects. A randomized study of women taking 1 milligram daily doses of oral minoxidil reported that hypertrichosis affected 27 percent of users, while 4 percent reported lower limb swelling. This study also reported that the average heart rate at rest of participants increased by 6.5 percent. (6)

Similarly, people using the lowest doses of oral minoxidil (0.25 milligrams per day) have a much lower rate of side effects. A retrospective study reported that swelling of the feet and ankles still occurred, but only in 4 percent of patients. And excessive or unwanted hair growth only occurred in 20 percent of patients. (4)

However, this study focused on men and differentiated facial hypertrichosis from body hypertrichosis. While body hypertrichosis occurred to 20 percent of the study’s participants, 52 percent said that they felt that the density of their facial hair had increased. (4)

Sublingual vs. Oral Minoxidil Side Effects

There are very few studies on sublingual minoxidil, but it seems to have fewer side effects than oral minoxidil pills – at least, as long as you’re comparing the same daily doses. And so far, the reduced rate of side effects seems to still be true even when you’re considering a 2:1 ratio (where sublingual minoxidil is given at twice the daily dose of oral minoxidil pills).

A retrospective case series of 64 people with pattern hair loss found that daily doses ranging between 0.45 milligrams and 0.9 milligrams caused no serious side effects. 7.8 percent of the study’s participants reported mild dizziness, while 3.1 percent reported lower limb swelling. Eight females (12.5 percent of the study) reported hypertrichosis. (7)

While these rates of side effects are much lower than those reported in oral minoxidil studies, the study acknowledged that further clinical trials are needed to determine if these reduced rates are accurate. However, these findings are supported by a phase 1B clinical trial that gave participants sublingual minoxidil in daily doses ranging between 0.45 and 4.05 milligrams. (8)

This study reported that oral minoxidil pills given at 2.5 or 5 milligram daily doses cause 16.8 to 37.2 ng/mL blood plasma concentrations within 30 minutes of taking a pill. In contrast, the sublingual minoxidil doses they studied produced a maximum blood concentration of 1.62 ng/mL. This is more than 12 times lower than the concentration that typically causes systemic side effects. (8)

The optimal dosing for sublingual minoxidil has yet to be established. However, the good results and low rates of side effects make it seem like it might become a very promising hair loss treatment in the next few years.   

Do Topical and Oral Minoxidil Have the Same Side Effects?

Topical and oral minoxidil share some of the same side effects. For example, hypertrichosis and hair shedding can also occur when using minoxidil foam and liquid. However, cardiovascular changes and lower limb swelling are unlikely side effects for foam and liquid minoxidil users, since the medication is not being taken systemically.

Hypertrichosis is also fairly uncommon for topical minoxidil users. When it does occur, it typically tends to affect people using 5 percent concentrations of minoxidil or higher.  A study comparing the effectiveness and side effects of 1-milligram daily doses of oral minoxidil versus 1-milliliter daily doses of 5 percent minoxidil solution reported that 27 percent of participants experienced hypertrichosis. In contrast, just 4 percent of topical minoxidil users reported this side effect. (5)

Hair shedding – sometimes referred to as minoxidil shedding – is a short-term side effect. It usually only occurs during the first few weeks or months of use, then goes away. This side effect can affect users of any hair loss treatment – from finasteride users to those receiving hair transplants.

Minoxidil liquid and foam also have skin-related side effects that oral minoxidil users are unlikely to experience. These include issues like skin irritation, redness, itchiness, dryness, burning, and discomfort, as well as dermatitis. (1)

These skin-based reactions are sometimes caused by allergic reactions to either the minoxidil drug itself or an ingredient commonly used in the topical medication’s preparation: propylene glycol. Minoxidil users who are allergic to propylene glycol can usually use minoxidil foam, which is typically prepared without this ingredient. (1)

Where To Buy Oral Minoxidil 

FDA-approved topical and foam minoxidil can be easily purchased over the counter at pharmacies, supermarkets, wholesale stores like Costco, and online. But if you’re trying to buy minoxidil in oral or sublingual form, it’s not so easily obtainable.

Oral minoxidil is generally sold in pharmacies as a blood pressure reducer (and in doses relevant to the treatment of that health issue). If you’re thinking of using oral minoxidil off-label, you’ll need a doctor to write you a prescription first.

Alternatively, check with hair loss clinics near you. Many of them may offer oral or sublingual minoxidil as hair loss treatment options. Just be aware that they won’t just write you a prescription – they’ll likely need to book you in for a consultation and make sure you don’t have any preexisting conditions that could be affected by taking this medication.


  1. Badri, T., Nessel, T. A., & Kumar, D. (2021). Minoxidil. In StatPearls [Internet]. StatPearls Publishing.
  2. Mayo Foundation for Medical Education and Research. (2022, November 1). Minoxidil (oral route) proper use. Mayo Clinic. Retrieved November 1, 2022, from 
  3. Panchaprateep, R., & Lueangarun, S. (2020). Efficacy and safety of oral minoxidil 5 mg once daily in the treatment of male patients with androgenetic alopecia: an open-label and global photographic assessment. Dermatology and therapy, 10(6), 1345-1357.
  4. Pirmez, R., & Salas-Callo, C. I. (2020). Very-low-dose oral minoxidil in male androgenetic alopecia: a study with quantitative trichoscopic documentation. Journal of the American Academy of Dermatology, 82(1), e21-e22.
  5. Jaén, P., & Arias-Santiago, S. Efficacy and safety of oral minoxidil 5 mg daily during 24-week treatment in male androgenetic alopecia Saoraya Lueangarun, MD, MS, King Chulalongkorn Memorial Hospital, Bangkok, Thailand; Ratchathorn Panchaprateep, MD, PhD, King Chulalongkorn Memorial Hospital, Bangkok, Thailand; Therdpong Tempark, MD, King Chulalongkorn.
  6. Ramos, P. M., Sinclair, R. D., Kasprzak, M., & Miot, H. A. (2020). Minoxidil 1 mg oral versus minoxidil 5% topical solution for the treatment of female-pattern hair loss: a randomized clinical trial. Journal of the American Academy of Dermatology, 82(1), 252-253.
  7. Sinclair, R., Trindade de Carvalho, L., Ferial Ismail, F., & Meah, N. (2020). Treatment of male and female pattern hair loss with sublingual minoxidil: a retrospective case-series of 64 patients. J Eur Acad Dermatol Venereol, 34(12), e795-e796.
  8. Bokhari, L., Jones, L., & Sinclair, R. D. (2021). Sublingual Minoxidil for the Treatment of Male and Female Pattern Hair Loss: a randomized, double-blind, placebo-controlled, phase 1B clinical trial. Journal of the European Academy of Dermatology and Venereology: JEADV.
  9. Ramos, P. M., Sinclair, R. D., Kasprzak, M., & Miot, H. A. (2020). Minoxidil 1 mg oral versus minoxidil 5% topical solution for the treatment of female-pattern hair loss: a randomized clinical trial. Journal of the American Academy of Dermatology, 82(1), 252-253.
  10. Ghonemy, S., Alarawi, A., & Bessar, H. (2021). Efficacy and safety of a new 10% topical minoxidil versus 5% topical minoxidil and placebo in the treatment of male androgenetic alopecia: a trichoscopic evaluation. Journal of Dermatological Treatment, 32(2), 236-241.
  11. Singh, S., Patil, A., Kianfar, N., Waśkiel‐Burnat, A., Rudnicka, L., Sinclair, R., & Goldust, M. (2022). Does topical minoxidil at concentrations higher than 5% provide additional clinical benefit?. Clinical and Experimental Dermatology, 47(11), 1951-1955.
  12. Yaghmaee, R., Mirbagheri, M., Pakdaman, M. H., Rad, F., & Gharibi, F. (2016). The effect of minoxidil 1 shampoo on androgenetic alopecia: A clinical trial study. Research Journal of Pharmaceutical, Biological and Chemical Sciences, 7(5), 856-862.
Published on November 30, 2022

Last updated November 2022

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