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Why Oral Minoxidil Isn't a Common Choice for Hair Loss Treatment

Oral Minoxidil for Hair Loss

Why Oral Minoxidil Isn't a Common Choice for Hair Loss Treatment

95% of hair loss is treatable.

And topical minoxidil is one of the most effective hair loss treatments available. It’s been consistently shown to be both effective and safe. Coupled with finasteride, it is the first-line treatment for hair loss.

And best of all, you don’t need a prescription to buy it.

However, topical minoxidil may not work for everyone. And, occasionally, it can cause irritation of the scalp.

In such cases, it may be appropriate to try oral minoxidil, the same active ingredient as the topical solution, but in pill form. There isn’t as much evidence for the effectiveness of minoxidil in oral form, and there is a small risk of serious side effects… but it is an option that individuals with hair loss may consider with their doctor.

In this article, we’ll share everything you need to know about oral minoxidil: what it is, how well it works, its side effects, and why we generally recommend topical minoxidil over oral minoxidil.

What is oral minoxidil?

Minoxidil is a medication originally developed in the 1970s as a treatment for hypertension. It relaxes smooth muscles in blood vessels, which dilates them. As researchers were studying its effects, they noticed that a common side effect of patients was hair growth, and this led to its development as a hair growth medication.

It was approved for use under the brand name Rogaine in the 1980s.

Cut to today: minoxidil is one of the most effective and popularly used hair loss treatments out there. It’s most commonly used as a topical solution applied directly to the scalp. More recently, it has been developed in a foam treatment that is also applied topically to the scalp.

Oral minoxidil has the same active ingredient as the topical solution, but it has been formulated as a pill that you ingest.

What is oral minoxidil used for?

Oral minoxidil is most commonly used to treat high blood pressure.

However, more recently, doctors have also started to prescribe it for hair loss treatment in cases where other treatment options are not working well or there are side effects.

Oral minoxidil vs. topical minoxidil

What’s the difference between the two? And when would you use oral minoxidil instead of topical minoxidil?

Topical liquid minoxidil is usually preferred for use over the oral version. The reason is that it is more strongly supported by research evidence and that it has fewer side effects.

Some patients discontinue use of topical minoxidil because it can cause unpleasant scalp itching (pruritus), scaling, and irritation. In those cases, they may prefer to take a low-dose of oral minoxidil instead and consult their doctor to obtain a prescription.

Effectiveness of oral minoxidil

So how effective is oral minoxidil for hair loss?

There is a large body of research that supports the effectiveness of topical minoxidil, but there is much less research on oral minoxidil for hair loss.

The best current research comes from a recent review of the studies on oral minoxidil. The study finds that oral minoxidil appears to be effective for androgenic alopecia (AGA), also known as “male-pattern hair loss”, the most common cause of hair loss in men. The study also found evidence that it is effective for female pattern hair loss.

Note that while some studies have found that low doses of oral minoxidil can be effective for men, other studies have actually found it to be less effective in men. Further research is needed to clarify the results.

So what does that all mean?

It means that the evidence for the effectiveness of oral minoxidil is not as strong as the evidence for topical minoxidil. But, the results seem to suggest that it may be an effective hair loss treatment.

Does oral minoxidil work for female pattern hair loss?

Yes, it appears to. Several studies have found that low-dose oral minoxidil can be an effective treatment for female hair loss. (Again, remember that while the research is promising, it is not as strong as the research on topical minoxidil.)

Does oral minoxidil work better than topical minoxidil?

There are relatively few studies that directly compare the effectiveness of topical vs. oral minoxidil.

In one of the few studies that we’re aware of, 1 mg of oral minoxidil was found to be as effective as 5% minoxidil topical solution for female pattern hair loss. There was no statistically significant difference in their effectiveness.

How long does oral minoxidil take to work

Oral minoxidil begins to work immediately, but it will usually be three to six months before you notice any changes to your hair. You’ll usually notice results after six months and you’ll likely achieve the “final” results after about a year.

This timeline is very similar to topical minoxidil.

Does oral minoxidil cause beard growth?

There’s very little research specifically on the use of oral minoxidil to improve beard growth.

One side effect of oral minoxidil is excessive hair growth, including on the face and body, so it could lead to beard growth in some people. In one small study of 25 patients, 13 (52%) reported perceiving hair density increases in their beard.

However, the research is very, very limited.

Oral minoxidil side effects

Is oral minoxidil safe?

Yes, it appears to be safe and well-tolerated by most healthy people when given at the lower doses (under 5 mg per day) usually prescribed for hair loss treatment.

However, there is a risk of side effects from oral minoxidil. Oral minoxidil side effects can include:

  • Skin rash
  • Itchy eyes
  • Temporary hair shedding
  • Excessive hair growth, including on the face and body
  • Fluid retention and swelling of the lower legs
  • Low blood pressure
  • Lightheadedness
  • Increased heart rate
  • Headaches
  • Weight gain

Oral minoxidil may cause more serious side effects

One of the main reasons that oral minoxidil is not commonly prescribed for hair loss is that it can cause serious side effects, such as pericarditis (inflammation of the lining of the heart) and weight gain caused by edema (swelling). While rare, these side effects can be life-threatening and require close monitoring of the patient. For this reason, patients taking oral minoxidil require regular follow-up by a medical professional.

Can too much minoxidil cause hair loss?

Yes and no.

One of the common side effects of minoxidil is that it can cause shedding. This is because it restarts the growth cycle of the hair. Minoxidil causes the older hairs to fall out so that they begin to grow back thicker.

So, yes, using minoxidil can cause some temporary loss of hair. But, no, using too much minoxidil will not accelerate permanent hair loss.

Does oral minoxidil cause weight gain?

Yes, some people experience weight gain as a side effect of oral minoxidil.

Oral minoxidil long term side effects

We are aware of very few studies that examine the long-term side effects of minoxidil for hair loss.

In one study, there were very minimal side effects noted for patients after a year of treatment. In another study on oral minoxidil for hypertension, minoxidil was found to have “relatively few side effects.”

Still, our lack of understanding of the long-term side effects of oral minoxidil is another reason why it is typically only prescribed after patients try a topical minoxidil solution.

When to not use minoxidil

Minoxidil is safe and well-tolerated for most people, but there are some people that should be cautious with its use. Ensure your doctor is aware of any of the following conditions before they give you a prescription for oral minoxidil:

  • Angina or recent heart attack
  • Heart disease
  • Heart failure
  • Hypertension
  • Pheochromocytoma
  • Liver impairment

Also, note that neither oral nor topical minoxidil has been evaluated for, or approved for, use with children.

Do I need a prescription to buy oral minoxidil in Canada?

Yes, you do need a prescription to buy oral minoxidil in Canada. You can consult a dermatologist or another qualified medical professional to obtain a prescription.

Remember, it is best practice for individuals seeking treatment for hair loss to start with topical minoxidil because it has fewer side effects than topical minoxidil. Essential Clinic does not prescribe oral minoxidil, but we do offer topical minoxidil for those looking to buy topical minoxidil in Canada.

Where can I buy oral minoxidil in Canada?

If you have a prescription for it, you can buy oral minoxidil from your local pharmacy.

Does Essential Clinic sell oral minoxidil?

No. Because its effectiveness is not yet well proven and because it can have more serious side effects, we only sell topical minoxidil products. You can check out all our hair loss treatment products here.

Find the best hair loss treatment for you

Confused about the best hair loss treatment for your needs?

No worries, we can help. Just start an online hair loss visit and we will guide you with an appropriate hair loss regimen.


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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.

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​​Sinclair, R. D. (2018). Female pattern hair loss: A pilot study investigating combination therapy with low‐dose oral minoxidil and spironolactone. International Journal of Dermatology, 57(1), 104-109.

Vañó-Galván, S., Pirmez, R., Hermosa-Gelbard, A., Moreno-Arrones, Ó. M., Saceda-Corralo, D., Rodrigues-Barata, R., ... & Bhoyrul, B. (2021). Safety of low-dose oral minoxidil for hair loss: A multicenter study of 1404 patients. Journal of the American Academy of Dermatology, 84(6), 1644-1651.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.