Minoxidil is best known as the hair regrowth treatment sold as Regaine, applied to the scalp. It began life as a blood pressure tablet, and still exists in that form for severe hypertension. The two uses are quite different, and the topical one only works while you keep using it.
What is Minoxidil?
The South African Medicine Price Registry lists minoxidil in two very different forms:
| Product | Schedule | Form | Strength |
|---|---|---|---|
| Regaine (for men / for women) | S2 | Topical solution | 20 mg/ml (2%) |
| Loniten | S4 | Tablet | 5 mg, 10 mg |
The tablet came first. Minoxidil was developed as a potent vasodilator for severe high blood pressure — it opens potassium channels in the smooth muscle of artery walls, relaxing them powerfully. It works, but it causes fluid retention and a fast heart rate, so it is now reserved for severe hypertension resistant to other treatment, and is given alongside a diuretic and a beta blocker to counter those effects.
The hair effect was discovered as a side effect. Patients on minoxidil tablets grew hair in unexpected places, and a topical version followed.
How it grows hair is still not fully settled, but it appears to widen the small blood vessels supplying hair follicles, prolong the growth phase of the hair cycle, and shorten the resting phase. It works on follicles that are miniaturising, not on follicles that are gone — which is why it does more for early thinning than for a scalp that has been bald for years.
Three things matter more than anything else about topical minoxidil, and all three cause people to give up:
It takes months. Nothing visible happens for at least eight to sixteen weeks, and judging it before four months is judging the wrong thing.
Shedding early on is normal and expected. In the first two to eight weeks, many people shed noticeably more hair. This is resting hairs being pushed out by new growth beneath, and it means the medicine is working. It settles.
It only works while you use it. Stop, and within three to six months the hair gained is lost, and thinning resumes where it would have been. Topical minoxidil is a continuing commitment, not a course.
What is Minoxidil commonly used for?
Topical (Regaine and similar):
- Male pattern hair loss (androgenetic alopecia) — its main use, most effective at the crown and vertex.
- Female pattern hair loss, where it is one of very few evidence-based options and works reasonably well.
- Telogen effluvium, the diffuse shedding that follows illness, childbirth, surgery, crash dieting or severe stress — though this usually recovers on its own.
- Alopecia areata, in some use, alongside other treatments.
- Eyebrow and beard growth, off-label.
Tablets (Loniten):
- Severe high blood pressure not controlled by other medicines, always with a diuretic and a beta blocker.
“Oral minoxidil” at low dose — 0.25 to 5 mg daily — has become an increasingly used off-label hair loss treatment internationally, prescribed by dermatologists. It is not a self-treatment, requires blood pressure and cardiac assessment, and should not be attempted by cutting up Loniten tablets.
Two things worth knowing before starting.
Hair loss has causes worth identifying. Thyroid disease, iron deficiency, some medicines and, in women, PCOS all cause hair loss and are treatable. A blood test before committing to years of topical treatment is sensible, particularly for women, where iron deficiency and thyroid problems are common and often missed.
Minoxidil and finasteride work differently and are often combined. Minoxidil stimulates follicles; finasteride blocks the hormone driving male pattern loss. Together they work better than either alone, though finasteride has its own considerations and is prescription-only.
How Minoxidil fits into this medicine category
| Group | Examples | Notes |
|---|---|---|
| Topical vasodilators | Minoxidil (Regaine) | Hair regrowth; must be continued |
| 5-alpha reductase inhibitors | Finasteride, dutasteride | Male pattern loss; prescription |
| Antiandrogens | Spironolactone | Female pattern loss; specialist use |
| Topical steroids | Clomaderm | Inflammatory scalp conditions |
| Antifungals | Canex V, ketoconazole shampoo | Fungal scalp infection, dandruff |
| Vasodilator tablets | Minoxidil (Loniten) | Severe resistant hypertension |
See the skin and wound care medicines hub.
What to check before using Minoxidil
For the topical solution, speak to a pharmacist or doctor if you:
- Have heart disease, arrhythmia, or low blood pressure. Some minoxidil is absorbed, and while topical use rarely affects blood pressure, it is worth mentioning.
- Have a scalp condition — psoriasis, eczema, sunburn, or broken skin. Absorption rises sharply through damaged skin, so treat the condition first.
- Are pregnant or breastfeeding. Minoxidil is avoided.
- Are under 18 or over 65.
- Have sudden or patchy hair loss, hair loss with a rash or scarring, or loss accompanied by other symptoms. That is not pattern hair loss and needs a diagnosis, not a regrowth product.
Practical points that determine whether it works:
- Apply it to a dry scalp, directly on the skin — not the hair.
- Use it twice daily, consistently. Once daily works less well.
- Wash your hands afterwards.
- Let it dry fully before bed. Minoxidil transfers, and unwanted facial hair in a partner sharing a pillow is a documented and avoidable problem.
- Keep it away from pets. Minoxidil is highly toxic to cats, and even small amounts licked from skin or a surface can be fatal. This is not a minor caution.
- Give it at least four months before deciding.
- Expect shedding at first.
For the tablets, this is specialist prescribing. Never take someone else’s, never adapt them for hair loss, and never stop them abruptly.
Possible cautions and when to ask a pharmacist or doctor
Topical minoxidil commonly causes scalp itching, dryness, flaking and irritation. Much of this is caused by the propylene glycol in the solution rather than the minoxidil — the foam formulation avoids it and suits people who react.
Seek prompt advice for:
- Unwanted facial or body hair growth, which happens with over-application or transfer, and reverses on stopping.
- A rash, severe itching or swelling of the scalp or face.
- Palpitations, chest pain, dizziness or fainting.
- Sudden unexplained weight gain, or swelling of the hands, ankles or face — possible fluid retention.
- Persistent scalp irritation.
Get emergency help for chest pain, severe breathlessness, fainting, or swelling of the face, lips or tongue with difficulty breathing.
Get emergency veterinary help immediately if a cat contacts minoxidil — licking a treated scalp, a spilled drop, or a used towel. It is frequently fatal, and time matters.
See a doctor rather than self-treating if:
- Hair loss is sudden, patchy, or in circular bald spots.
- There is scalp redness, scaling, pain, or scarring — scarring alopecia is permanent if untreated, and needs urgent specialist assessment.
- Hair loss comes with tiredness, weight change, irregular periods, or new facial hair — thyroid disease, iron deficiency and PCOS are all treatable causes.
- You are a woman with significant hair loss, where investigation is particularly worthwhile.
- There is no improvement after six to twelve months of consistent use.
Related medicine guides
Frequently asked questions
What is minoxidil used for? Applied to the scalp, it treats male and female pattern hair loss. As a tablet, it treats severe high blood pressure not controlled by other medicines.
How long before I see results? At least eight to sixteen weeks, and four months before judging it properly.
Why am I losing more hair since starting? Shedding in the first two to eight weeks is expected — resting hairs pushed out by new growth beneath. It settles, and it means the medicine is working.
What happens if I stop? Within three to six months you lose the hair you gained and thinning resumes. It is a continuing treatment, not a course.
Does it work on a fully bald scalp? No. It works on miniaturising follicles, not on ones that are gone. It does far more for early thinning.
Can women use it? Yes — it is one of very few evidence-based options for female pattern hair loss, and works reasonably well.
Why does my scalp itch? Usually the propylene glycol in the solution rather than the minoxidil. The foam formulation avoids it.
Is it dangerous to pets? Yes. Minoxidil is highly toxic to cats and frequently fatal. Keep it away from them, let it dry fully, and do not let a cat contact your scalp or towels.
Can I take the tablets for hair loss? Not on your own. Low-dose oral minoxidil is used off-label by dermatologists but requires blood pressure and cardiac assessment.