Minoxidil for hair loss: how it works and what to expect

What minoxidil is and how it works

Topical minoxidil is a solution or foam applied to the scalp, most often in 2% or 5% strengths. It lengthens the growth phase of the hair cycle, widens small blood vessels in the scalp and can make hair shafts thicker. It is also made as a tablet, oral minoxidil, which is a prescription medicine.

It is used for androgenetic alopecia, the common pattern hair loss: a receding hairline or thinning crown in men, and a widening parting in women. It is not a fix for every kind of hair fall. Shedding after illness or from low iron, patchy hair loss and scarring conditions need a different plan, which is why diagnosis comes first.

What the trials show

In a 48-week trial of 393 men with thinning at the crown, 5% minoxidil added about 18.6 hairs per square centimetre, 2% added 12.7, and a placebo lotion 3.9. In women, pooled trials show about 12 to 14 more hairs per square centimetre than placebo. Both 2% and 5% strengths help women; in men, 5% did better than 2%.

Those numbers are averages from a small marked area of scalp. Results vary between people, and the trials say less about how full your hair looks in the mirror than about hair counts. Most trial data cover 16 to 48 weeks of treatment, with benefit over placebo reported at 6 months and beyond.

How it is used

Your doctor will tell you which form and strength to use and how often. In general, it is applied to a dry scalp, to the thinning area rather than along the hair, and left on. Wash your hands afterwards and let it dry before lying down, so it does not transfer to your face or pillow.

Some solutions contain propylene glycol, which can irritate the scalp, and higher strengths cause more local irritation. If you itch or flake, your doctor may suggest a different formulation rather than stopping altogether. Regular use matters more than technique: stopping and starting makes it hard to judge whether it is working.

Gentle scalp care helps you stay comfortable while you use it. If you want a mild shampoo or conditioner to use alongside treatment, you can browse our hair care range, and your doctor can advise what suits your scalp.

Browse the hair care range

The early shedding phase

Many people notice more hair fall between about 2 and 8 weeks after starting. Minoxidil pushes resting hairs out so that new growing hairs can replace them. This is usually temporary, and it is one of the most common reasons people give up too early.

Shedding is not always the minoxidil, though. If heavy shedding continues well beyond the first couple of months, or you notice new patches or a sudden change, see your doctor. Another cause, such as low iron, a thyroid problem or a recent illness, may be adding to it.

Side effects and who should avoid it

Most side effects of topical minoxidil are local and mild, but they are worth knowing before you start.

• Scalp irritation: Itching, flaking or redness are the most common problems. In one evidence summary, scalp eczema affected about 16% of people using topical minoxidil.
• Unwanted hair growth: Fine hair on the forehead, cheeks or arms is more likely with stronger solutions. It usually fades within 1 to 3 months of stopping.
• Headache: Uncommon with the topical form, reported in about 2% of users in one summary. Mention it to your doctor if it happens.
• Pregnancy and breastfeeding: Minoxidil is avoided during pregnancy and breastfeeding.

Oral minoxidil and combinations

Low-dose oral minoxidil is a prescription option some doctors use, for example for people who cannot tolerate the scalp treatment. It has its own side effects, including unwanted hair growth and, in some people, dizziness, a faster heartbeat or ankle swelling, so it needs a medical assessment first. Never take blood pressure tablets meant for someone else, or adjust a dose yourself.

For men, minoxidil is often combined with finasteride, a prescription tablet that lowers the hormone DHT; in trials in men, finasteride did better than topical minoxidil alone. Women may be offered other prescription medicines, such as spironolactone. In-clinic treatments such as PRP or GFC can be added for some people, but they work alongside these medicines, not instead of them.

Hair fall treatment for men

Why you have to keep using it

Minoxidil does not change the underlying cause of pattern hair loss. If you stop, the hair it was supporting is usually shed within 3 to 4 months, and thinning carries on at its natural pace.

That is why it helps to decide at the start whether you are willing to use it long term, and why a review at about a year is useful. It gives you and your doctor a fair basis to continue, change or add treatment.

Hair fall treatment for women