The short answer: it depends on what kind of hair loss you have. Male pattern hair loss, the most common kind by far, cannot be switched off, but it can usually be slowed, stabilised and partially reversed with two well-evidenced treatments: finasteride and minoxidil. Shedding caused by stress, illness or nutritional deficiency usually stops by itself once the trigger resolves. And a long list of heavily marketed products does very little. Here is how to tell which situation you are in and what actually works.
First: what kind of hair loss is it?
Pattern loss shows up as a receding hairline and thinning crown, gradually, in a recognisable shape. Diffuse shedding all over the scalp a few months after a stressful event, illness or rapid weight loss points to telogen effluvium, which typically recovers without treatment. Patchy, coin-shaped loss suggests alopecia areata, which is autoimmune and needs a GP or dermatologist rather than online treatment. Our guide to telogen effluvium vs pattern loss helps you tell the difference.
What has strong evidence
For male pattern loss, two treatments dominate the evidence. Finasteride is a daily prescription tablet that lowers DHT, the hormone that shrinks genetically sensitive follicles; in trials most men stop losing ground and a substantial proportion regain some density. Minoxidil is a topical treatment that pushes follicles into their growth phase. They work by different routes, which is why using both together often outperforms either alone.
The strength of that evidence is worth spelling out, because hair loss is a market full of thin claims. Finasteride has been studied in randomised trials over five years, involving thousands of men, with the large majority maintaining or improving their hair count against a placebo group that continued to lose. Minoxidil has decades of trial data in both men and women. A 2017 systematic review pooling the available trials found both treatments clearly outperformed placebo, and NICE guidance for UK clinicians names them as the standard options for male pattern loss. Nothing else sold for hair loss comes close to that weight of evidence.
What has weak or no evidence
- Biotin and most hair supplements, useful only if you have a genuine deficiency, which is uncommon.
- Caffeine shampoos, laboratory findings, thin human evidence.
- Laser combs and helmets, some small studies, modest effects at best, expensive.
- Rosemary oil, one small trial against low-dose minoxidil; not nothing, not much.
- Scalp massage, cold water, standing on your head, folklore.
None of these is dangerous, but every month spent on them while pattern loss progresses is follicle ground you may not get back. The honourable mention is ketoconazole shampoo, which has modest supporting data and treats the scalp conditions that can add shedding on top of pattern loss; it is a reasonable supporting act, not a lead treatment. The pattern to notice in the marketing is that products with weak evidence sell certainty, while the treatments with strong evidence come with honest caveats about timelines and side effects. Counterintuitively, the caveats are the trust signal.
Health checks worth doing first
A small number of medical issues can cause or worsen shedding, and they are worth ruling out before you commit to a year of treatment: low iron, thyroid problems, and, less often, vitamin deficiencies. A GP can check these with a routine blood test, and the NHS hair loss page lists the signs that should prompt a visit, such as sudden loss, itching or soreness. Fixing a deficiency will not reverse pattern loss, but it removes a second cause that can make thinning look faster than it is, and it means any treatment you start gets a fair test.
Why acting early matters
Treatment is much better at keeping hair than at regrowing it. A follicle that has spent years miniaturising eventually stops producing hair at all, and no tablet or liquid revives it; at that point the only option that moves hair is a transplant, which itself works best alongside medication to protect the surrounding hair. If your hairline or crown is visibly changing and it bothers you, the evidence favours assessment sooner rather than later.
A useful way to think about it: every stage of pattern loss is easier to hold than the one after it. A man treating at Norwood stage two, with a slightly receded hairline, is defending nearly a full head of hair; a man starting at stage five is trying to claw territory back, which medication does far less reliably. This is why the common strategy of waiting to see how bad it gets is quietly the most expensive one. Waiting does not improve the decision; it only shrinks what treatment can protect.
The practical path
Confirm the type of loss, ideally with photos over time. If it is pattern loss and you want to treat it, finasteride, minoxidil or both, prescribed and reviewed properly, is the evidence-based route. If shedding is sudden, patchy or accompanied by other symptoms, see your GP first.
And set expectations by the calendar, not the mirror. Hair grows in cycles measured in months, so judging a treatment at week six tells you nothing. Take a photo in consistent light before you start, again at three months, and make the real decision at twelve. Our guide to tracking hair loss progress shows how to do this properly, it is the difference between an informed decision and an anxious one.
