Written for Stock My Medicine and clinically reviewed by Hajra Dhanchora, MPharm (GPhC 2216990).
Minoxidil is the only hair-regrowth treatment you can buy without a prescription that has real trial evidence behind it, and Regaine is the brand that has carried it for thirty years. It does work, for most men, most of the time, but it asks for patience, honesty about what "work" means, and a commitment most people don't expect. Here's the straight version.
How does minoxidil work?
Nobody is entirely sure, which is unusual for a medicine this old. What's known: it widens the tiny blood vessels around the follicle, and it pushes resting follicles back into the growing phase and keeps them there longer, so hairs that were thinning and shrinking grow back thicker for longer. It does not block DHT, the hormone behind male-pattern hair loss, which is why it treats the symptom rather than the cause and why the effect stops when you do.
Does minoxidil work, and for whom?
In the trials behind Regaine for Men Extra Strength (5%), around nine in ten men saw hair loss slow or stop, and about six in ten saw regrowth, most of it moderate rather than dramatic. It works best on the crown and vertex in men aged 18 to 65 whose thinning has been going on for less than ten years, and less well on a receding front hairline. It's for hereditary, male-pattern loss; it won't help sudden or patchy loss, which needs a GP. Women get a version too: Regaine for Women, used once a day.
How long does minoxidil take to work?
Longer than you want. Most men see the first real change at 8 to 16 weeks, and Regaine's own guidance is to judge it at four months, not four weeks. The single biggest reason minoxidil "doesn't work" is that people stop in month two.
The shedding phase nobody warns you about
Between roughly weeks two and eight, many men lose hair. This is the treatment working: minoxidil pushes old, resting hairs out so that new, thicker ones can come through, and the shed is those old hairs going early. It settles within a few weeks. Knowing it's coming is the difference between finishing the course and giving up at exactly the wrong moment.
How to apply minoxidil: foam or solution?
Both are 5% minoxidil, applied twice a day to a dry scalp, and the difference is texture. Regaine foam is half a capful, rubbed in with dry fingers, dries in minutes and doesn't drip; most men prefer it. Regaine solution is 1ml from the dropper, spread over the thinning area, and suits longer hair where foam gets lost. Either way: part the hair, apply to the scalp not the hair, wash your hands, and leave it at least four hours before washing or swimming. The three-month pack is the sensible way to buy, because three months is the minimum fair trial.
Is minoxidil safe? The side effects
Yes, at this dose and used on the scalp. The common side effects are local: an itchy, dry or flaky scalp, more often with the solution because of its alcohol content, and occasionally unwanted hair on the forehead or cheeks if the product runs. Rarely, enough is absorbed to cause dizziness, a fast heartbeat, headache or swollen hands and feet; stop and see a GP if that happens. It's not for anyone under 18, over 65, with a sudden or unexplained pattern of loss, or with heart disease or low blood pressure without a doctor's say-so, and it shouldn't be used in pregnancy or breastfeeding. Oral minoxidil tablets are prescription-only and a different conversation.
What happens if you stop using minoxidil?
The regrown hair goes. Because minoxidil doesn't fix the underlying cause, follicles return to their previous course within three to four months of stopping, and you end up roughly where you'd have been without it. That's not a reason not to start; it's the reason to decide up front whether twice a day, indefinitely, is a routine you'll keep. Combined with a DHT-blocking prescription treatment from a GP or online clinic, minoxidil is the standard two-pronged approach. Everything we stock is in the hair loss range, and our pharmacist can talk you through it. For the other question men ask us most, see how long Viagra lasts.
Frequently asked questions
Can I use minoxidil once a day instead of twice?
Once a day gives some benefit but the trials, and the licence for the men's product, are for twice daily. If twice is unrealistic, once daily consistently beats twice daily for a fortnight then nothing.
Does minoxidil work on a beard?
It's not licensed for it, and applying it to the face raises the chance of absorption side effects. Ask a GP or pharmacist rather than experimenting.
Can I buy minoxidil over the counter?
Yes: Regaine for Men and Regaine for Women are general-sale medicines in the UK, with no questionnaire or prescription needed.