Safety information · Internal patient-safety page
Minoxidil safety summary
Minoxidil widens scalp blood vessels and prolongs the active growth phase of hair follicles. It is the most widely used topical treatment for androgenetic alopecia in men and women, and is sometimes prescribed orally at very low doses (0.25–2.5 mg) for selected patients.
What it's used for
- Topical solution / foam: 1 mL applied to a dry scalp twice daily; do not rinse for at least 4 hours.
- Initial shedding around weeks 2–8 is common. This is the old hair making room for the new growth, not a worsening.
- Visible response usually appears at 3–6 months; stopping reverses the gains.
- Low-dose oral minoxidil is an off-label option for selected patients; only when prescribed by your doctor.
Most common side effects
- Scalp itch, dryness, redness or flaking: often from propylene glycol in the solution; the foam is usually better tolerated.
- Initial telogen-effluvium shedding (transient).
- Unwanted facial hair growth (hypertrichosis), especially in women, usually mild.
- Headache and mild dizziness: more common with oral minoxidil.
- Ankle swelling or weight gain: primarily with oral minoxidil; flag promptly.
Serious side effects: stop and seek care
- Sudden palpitations, chest pain or shortness of breath: particularly with oral use; emergency services first.
- Marked ankle / leg swelling or rapid weight gain (>1 kg in a few days).
- Severe allergic reaction (widespread rash, swelling, breathlessness).
- Persistent dizziness or fainting.
Who should not use it
- Pregnancy or breastfeeding.
- Children under 18.
- Known hypersensitivity to minoxidil or propylene glycol (for the solution).
- Active scalp disease: broken skin, severe eczema or psoriasis on the scalp until treated.
- Significant cardiovascular disease or pheochromocytoma: discuss with the doctor before any oral use.
Interactions to flag
- Other topical scalp products: apply minoxidil to a dry scalp and wait at least 30 minutes before any other topical.
- Antihypertensives: additive blood-pressure-lowering effect, particularly with oral minoxidil.
- Topical corticosteroids on the scalp: can change the absorption profile; coordinate with the doctor.
- Pets: household cats are very sensitive to minoxidil; wash hands and avoid contact with the cat after application.
Message us in the app chat if you notice any of these
- Heart symptoms: palpitations, chest discomfort, breathlessness.
- Marked swelling of the ankles or sudden weight gain.
- Persistent scalp irritation: the foam is usually a better fit if the solution stings.
- Pregnancy or planning pregnancy: stop the medicine.
AEMPS CIMA: Minoxidil topical 5%
Back to your consultationThis page summarises information from the regulator-approved leaflet for reference only. It is not medical advice and does not replace the assessment of an EU-licensed doctor. Your doctor will review your individual history, dose and interactions during your consultation.