A strong vasodilator, also a hair-loss treatment
Minoxidil
A strong vasodilator for resistant high blood pressure; the same drug applied to the scalp treats hair loss.
What is Minoxidil?
Minoxidil is a powerful vasodilator that widens the arteries to lower blood pressure. Taken by mouth, it is reserved for hard-to-control (resistant) high blood pressure and is always combined with a beta-blocker and a water tablet to offset the fast heartbeat and fluid build-up it causes. The very same drug, applied as a lotion or foam to the scalp (brand Regaine), is a well-known treatment for hair loss. A notable effect of the tablets is increased growth of body and facial hair.
Education and reference only. This is a plain-language guide to Minoxidil — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Minoxidil is a strong vasodilator, meaning it relaxes and widens the arteries. As a tablet it is a potent blood pressure medicine kept for high blood pressure that has not responded to other treatments. Interestingly, the same medicine causes hair growth, and when applied directly to the scalp as a lotion or foam (sold as Regaine) it is used to treat pattern hair loss. The tablet form is taken by mouth and always alongside other medicines; the scalp form is used only on the scalp.
How it works
Minoxidil relaxes the muscle in artery walls, opening the arteries wide so blood pressure falls markedly. This strong effect makes the heart beat faster and the body hold on to fluid, so the tablets are always given with a beta-blocker to steady the heart and a water tablet to clear fluid. A separate effect of minoxidil is that it stimulates hair follicles, which is why it causes extra body hair when taken as tablets and is used on the scalp to encourage hair regrowth.
Company & origin
Originated / developed by: Generic (long-established).
A long-established medicine used in the UK as a powerful blood pressure treatment by mouth and, applied to the scalp, as a hair-loss treatment.
What it treats
Conditions Minoxidil is used for
Practical use
How to take Minoxidil
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- If taking the tablets, take them regularly as prescribed, along with the beta-blocker and water tablet you have been given.
- Do not take the blood pressure tablets without the partner medicines, as this can strain the heart and cause fluid build-up.
- Expect increased body and facial hair with the tablets; discuss this with your prescriber if it troubles you.
- If using the scalp lotion or foam, apply it to a dry scalp as directed and wash your hands afterwards.
- With the scalp product, keep using it regularly, as any hair benefit is usually lost within months of stopping.
- Report rapid weight gain, swelling or breathlessness with the tablets, as these can signal fluid retention.
Weighing it up
Advantages & disadvantages of Minoxidil
Advantages
- A powerful option for high blood pressure that has not responded to other medicines.
- The scalp lotion or foam (Regaine) is a recognised treatment for pattern hair loss.
- Effective at lowering blood pressure when combined with the right partner medicines.
Disadvantages
- The tablets cause a fast heartbeat and fluid retention, so they must always be taken with other medicines.
- Commonly increases body and facial hair, which can be unwelcome with the tablets.
- The scalp product only works while it is used, with hair gains usually lost after stopping.
Practical use
Good to know
It helps to know that minoxidil has two quite different uses: strong blood pressure tablets and a scalp treatment for hair loss, both being the same active medicine. As tablets it is only used for resistant high blood pressure and must be combined with a beta-blocker and a water tablet, because on its own it causes a fast heartbeat and fluid retention that can be harmful. A well-known effect is increased growth of body and facial hair, which can be unwelcome with the tablets but is the desired effect on the scalp. The scalp lotion or foam works only while it is used; hair gains are usually lost over a few months if it is stopped. Used on the scalp it is generally safe, though it can cause scalp irritation.
Who should not take it / use with caution
- People with certain serious heart conditions, such as some after a recent heart attack, should not take the tablets.
- The tablets are avoided in people who cannot also take a beta-blocker and a water tablet to balance their effects.
- The scalp product should not be applied to broken, inflamed or infected scalp skin.
Monitoring
- Blood pressure and heart rate checks while taking the tablets.
- Watching weight and for swollen ankles or breathlessness, which can signal fluid retention.
- Reviewing the scalp response and any irritation when using the lotion or foam.
Side effects
- Increased body and facial hair, a fast heartbeat and fluid retention with the tablets.
- Swollen ankles, weight gain from fluid, and feeling faint on standing with the tablets.
- Scalp irritation, dryness or itching with the lotion or foam.
Key interactions
- Adds to the blood-pressure-lowering effect of other blood pressure medicines.
- Deliberately combined with a beta-blocker and a water tablet to control heart rate and fluid.
- Care is needed with other medicines that affect the heart or blood pressure, so tell your prescriber what you take.
Available as: Tablets taken by mouth, and a lotion or foam applied to the scalp.
Answers
Minoxidil: frequently asked questions
Is the blood pressure tablet the same as the hair-loss treatment?
Yes, both contain minoxidil; the tablets treat resistant high blood pressure, while the lotion or foam (Regaine) applied to the scalp treats hair loss.
Why must the tablets be taken with other medicines?
Minoxidil tablets cause a fast heartbeat and fluid retention, so a beta-blocker and a water tablet are needed to offset these effects safely.
Will the tablets make my hair grow?
Increased body and facial hair is a common effect of the tablets; on the scalp the same effect is used deliberately to treat hair loss.
Does the scalp treatment work permanently?
No. Any hair benefit lasts only while you keep using it, and gains are usually lost within a few months of stopping.
Is the scalp lotion safe?
Used as directed it is generally well tolerated, though it can cause scalp irritation, dryness or itching; avoid broken or inflamed skin.
Authoritative sources
- BNF
- NICE CKS
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