PRP and the Rest
Once you are past finasteride and minoxidil, the evidence thins out quickly and the marketing thickens. This page is a sorting exercise rather than a recommendation.
The useful question for anything in this category is not does it work but compared with what, at what cost, and instead of what. A treatment that produces a small effect for a large annual fee is competing with a generic tablet that costs a few pounds a month, and it usually loses.
On this page
Platelet-rich plasma
PRP involves taking your blood, spinning it to concentrate the platelets, and injecting that concentrate into the scalp. The theory is that growth factors in the platelets stimulate follicles.
The evidence is genuinely mixed rather than absent. Several small trials show measurable improvements in hair density; others show little. The bigger problem is that protocols vary enormously between clinics, in how the blood is spun, what concentration results and how often it is repeated, so results from one clinic say very little about another.
Where it seems most defensible is as an adjunct for someone already on medication, and sometimes around the time of a transplant. Where it is least defensible is as a replacement for drugs, sold as a course of several sessions a year at a cost that would buy decades of finasteride.
If you want to try it, ask the clinic what protocol they use and what they measure. A clinic that photographs and counts before and after is taking it seriously.
Before booking a course
Ask what the total annual cost is including maintenance sessions, and write that number next to the annual cost of the two proven drugs. Seeing them side by side answers the question faster than any discussion of the evidence.
Microneedling
Rolling or stamping fine needles across the scalp to create controlled micro-injury, on the theory that healing stimulates follicles and that it improves absorption of topical minoxidil.
The evidence for microneedling combined with minoxidil is reasonably encouraging, more so than for microneedling alone. It is cheap, it can be done at home, and the main risks are infection and overdoing the depth.
It is a fair adjunct if you are already using minoxidil. Needle length, frequency and hygiene all matter, and doing it weekly with a clean device at a modest depth is the sensible version.
Ketoconazole shampoo
An antifungal shampoo with some evidence of a mild anti-androgenic effect on the scalp, alongside its actual job of controlling the yeast involved in dandruff and seborrhoeic dermatitis.
Cheap, harmless, and plausibly a small positive, particularly if you also have a flaky scalp. Nobody should expect it to hold hair on its own, and using it two or three times a week is a reasonable habit rather than a treatment plan.
Laser devices and supplements
Low-level laser therapy, sold as caps, combs and helmets, has some trial support for modest density improvements and a plausible mechanism. It is also expensive for what it delivers, and the trials are mostly industry-funded. It is not harmful. It is a long way down the list of things to spend money on.
Supplements are the weakest category. Biotin does nothing for hair unless you are genuinely deficient, which is rare. Saw palmetto is sold as a natural DHT blocker with far weaker evidence than finasteride and no dose standardisation. Multivitamins for hair are a marketing category rather than a clinical one.
Correcting a real deficiency is different. If your loss is diffuse rather than patterned, low iron, thyroid problems and significant nutritional deficiency are all worth testing for, and treating one of those can genuinely reverse shedding.
Before buying anything in this category
Get your ferritin and thyroid checked if the shedding is diffuse rather than in a pattern. Finding a treatable cause is worth more than any product on this page, and it costs a blood test.
Frequently asked questions
Does PRP work?
The evidence is mixed and protocols vary wildly between clinics. It is an adjunct at best and not a replacement for medication. See platelet-rich plasma.
Is microneedling worth doing?
Combined with minoxidil, reasonably so, and it is cheap. Alone, less convincing. See microneedling.
Do laser caps work?
There is some trial support for modest gains, mostly industry-funded, at a high price relative to the benefit. See laser devices and supplements.
Should I take biotin?
Not unless you are deficient, which is uncommon. It also interferes with some blood tests, so tell your doctor if you take it.
What about saw palmetto?
Weaker evidence than finasteride, no dose standardisation, and the same mechanism claimed. If you want DHT blocked, use the drug that was tested.