Minoxidil (Topical)

What is minoxidil and what does it do?

Minoxidil was first developed as an oral blood pressure medicine, and hair growth was noticed as a side effect. Applied to the scalp, it is converted by follicle enzymes into its active form, minoxidil sulphate. It is thought to open potassium channels, improve blood flow around follicles, prolong the growth phase of the hair cycle and enlarge shrunken follicles. It is used for androgenetic alopecia in both men and women. Increased shedding in the first weeks is common as resting hairs are pushed out. Benefits take months to appear and depend on continued use; stopping leads to gradual loss of the gained hair. [1]

What does the evidence show?

Topical minoxidil is supported by multiple randomised placebo-controlled trials in men and women with pattern hair loss, and it is a standard first-line treatment in dermatology guidance. Reviews report that a proportion of users see regrowth while many see stabilisation rather than dramatic change. Response varies between individuals, partly depending on follicle enzyme activity. Evidence for other types of hair loss is more limited.

Who should avoid minoxidil?

Topical minoxidil should not be used in pregnancy or breastfeeding, or on an irritated, sunburnt or broken scalp. People with heart conditions or low blood pressure should check with a doctor first. Scalp itching, flaking or dermatitis can occur, sometimes from propylene glycol in solutions. Unwanted facial hair growth may occur, especially in women.

Is minoxidil available in Singapore?

Topical minoxidil products are registered medicines in Singapore and are generally available from pharmacies, where a pharmacist can advise. Oral minoxidil used for hair loss is prescribed by doctors outside its original indication and requires medical supervision. Product category can depend on strength, so check with a pharmacist or doctor.

If a dark patch, breakout or irritation is not responding to what you are using, the next step is a diagnosis rather than another product. See the Skin A–Z library for related ingredients.