There is a TikTok doing the rounds where a dermatologist (@dermatologysurgeon, the one with the calm voice and the lab coat) sits down and rates the viral hair growth products her clinic patients keep asking about. Hair serums. Rosemary oil. Minoxidil knockoffs. The clip is short, blunt, and a bit funny, and it has cracked 355,000 views in a couple of days for one good reason. Everyone watching it has at some point stood in Boots, holding a bottle with a TikTok-famous label, wondering if it was going to do anything at all.
If you have ever been that person, this one is for you. Below is a plain English read on what dermatologists actually back, what is mostly noise, and what to do in the months it takes for any of it to work.
It is also worth saying upfront: we run a hair brand, so we have skin in the game. We will flag where that is true.
why tiktok is not a dermatologist
Useful starting point: only around 10% of alopecia content on TikTok comes from a medical professional. The rest is creators, brands, and people who genuinely mean well but are quoting each other in a loop.
That is not a moral failing. It is just how the platform works. A 30 second clip of a girl pouring rice water on her scalp gets more reach than a 12 week clinical trial with proper controls. So when a dermatologist like @dermatologysurgeon takes the time to weigh in, it is worth pausing for. She is essentially doing free triage on a market that is otherwise a bit of a free for all.
About 8 million women in the UK are affected by some form of hair loss or alopecia. That number is not made up of impulse buyers. It is made up of people who have been quietly worrying for months and finally clicked checkout on something promising. The viral products are not all bad. Some are even quite good. But the spread between the best and the worst is huge.
the products dermatologists actually approve
Start with the boring ones, because the boring ones work.
Topical minoxidil first. The 2% and 5% solutions are the only over-the-counter hair loss treatments the MHRA has licensed for both men and women in the UK. You can walk into a pharmacy and pick it up. It is the closest thing to a sure bet in the whole category, which is why most dermatologists mention it first.
Then finasteride, which is licensed in the UK for men only and prescription only. Worth a separate flag here: in April 2024 the MHRA strengthened the warnings around psychiatric side effects and now requires a patient alert card at the point of dispensing. Not a reason to avoid it. A reason to have a proper conversation with a GP rather than ordering it from a random website.
Microneedling combined with minoxidil is the slightly less obvious one. A 2025 systematic review in the Archives of Dermatological Research showed the pairing beats minoxidil alone for hair count and fibre diameter, with the strongest signal at the 12 week mark. It is the combo a lot of dermatologists actually use on themselves.
Peptide serums (The Ordinary Multi-Peptide Serum is the one your group chat keeps mentioning) sit in a slightly weaker evidence bracket. Not a miracle. Cheap, well tolerated, evidence pointing in roughly the right direction. A reasonable add-on, not a replacement.
That really is the short list. Everything beyond it is either unproven, niche, or marketing.
what the evidence really says about rosemary oil and serums
Rosemary oil is the viral product that has become a sort of religion online. The case for it rests on one 2015 study where it performed roughly as well as 2% minoxidil. One study. A small one. With limitations the original authors openly noted.
Dr Mia Jing Gao, a consultant dermatologist in London, has been blunt about this in public: there is no good evidence that rosemary oil regrows hair, and applied undiluted it can actually irritate the scalp enough to make shedding worse. She is not anti-rosemary. She is anti-treating it like a substitute for something that has been through proper trials.
None of which means do not use it. Plenty of people enjoy it as part of a calming scalp routine and feel fine. The point is that it should not be your main treatment. If it is the only thing standing between you and continued shedding, you are in trouble.
the minoxidil reality check
Now the bit no minoxidil ad will ever say out loud.
In the original studies, the 5% solution was rated "very effective" in only 15.9% of patients and "effective" in another 47.8%. Add those up and you get a real-world success rate of around two thirds. Decent, but a million miles from the "guaranteed regrowth" energy of the ads.
It also takes three to six months before you can fairly judge it. Between weeks two and eight you will probably shed more than usual, which is the part that makes most people panic and quit. That shedding is the old, weaker hairs being pushed out by new ones cycling in. It is the treatment working, not failing.
And if you stop, you lose the gains. Slowly, but you lose them. It is more like flossing than a course of antibiotics.
viral hacks to skip entirely
Some of the trending ones are not worth your time or your scalp.
Onion juice has decent evidence for alopecia areata, which is a specific autoimmune condition, not the general thinning most viewers are dealing with. Outside that narrow lane it is mostly a smell.
Egg yolk masks, garlic oil, rice water rinses, castor oil cocktails. None have meaningful clinical evidence for regrowing hair on a thinning scalp. Some can irritate the skin or block follicles if you go heavy. A 2026 Medscape survey found 28% of social media users who tried influencer-recommended hair loss treatments reported side effects. Not a small number for products that were supposed to be gentle.
If a method requires a 47 step routine and a smoothie of pantry items, it is not a treatment. It is content.
realistic timelines: what no one tells you
Up to 50% of your hair can be lost before thinning becomes visually obvious to anyone else. By the time you notice in the mirror, you have usually been losing for a while. That sounds bleak but it is genuinely useful information, because it explains why a four week trial of any product will tell you almost nothing.
Three months is the minimum fair review window. Six is more like it. A year is when you can confidently say whether something is working.
The viral cycle, by contrast, runs in days. Which is why so many people end up cycling through six "miracle" products in a year and never giving anything a fair go. If you are going to try one of the evidence-based options, give it a real chance before swapping.
what to do right now while you wait
This is the bit the dermatologist clips never quite get to, and it is the bit that matters most for day to day life.
First, get a diagnosis. A GP referral or a session with a trichologist will tell you what kind of hair loss you actually have, which makes choosing a treatment about a thousand times less random. Female pattern hair loss, telogen effluvium, traction, and alopecia areata all want different things.
Second, pick one evidence-based treatment and stick with it for the full window. Do not stack four. You will never know what worked.
Third, be kind to the hair you have. Skip the tight ponytails, the daily blow dry on max heat, the bleach over already fragile lengths. None of that grows hair, but all of it loses it.
Fourth, and this is where most articles go quiet, do something about the look in the meantime. Sitting through three to six months of "trust the process" while you avoid mirrors and reshape your parting is not free. It quietly costs you.
This is the slot Hair Guru London's cotton fibres are designed for. They are not a treatment and they will not regrow a single strand. What they do is cling to the hairs you already have using static and fibre structure, so a thinning patch or a wider parting looks full again within about 30 seconds. Cotton rather than keratin, which means no harsh chemicals near the scalp while you are also using minoxidil or peptide serums. You get to look like yourself while the slower work is happening underneath.
That is the deal we wish someone had spelled out years ago. The viral hair growth products that actually work are slow. The fix for how you feel about your hair in the meantime can be quick. Those are different problems and they need different answers.
frequently asked questions
Does minoxidil actually regrow hair or just stop it falling out?
Both, depending on the person. The trials show real new growth in a meaningful percentage of users, alongside a slowing of further loss. The catch is that the regrowth is usually finer than your original hair and you have to keep using it to keep it.
How long does it take for hair growth products to work?
Three months minimum to start judging, six months for a fair review, twelve months for a confident verdict. Anything promising results in two weeks is selling you a story.
Is rosemary oil as good as minoxidil for hair loss?
One small 2015 study suggested it performed similarly to 2% minoxidil. That is interesting but not enough to base a treatment plan on. UK dermatologists generally treat it as a nice-to-have, not a replacement for licensed options.
Which hair loss treatments does the NHS recommend?
The NHS routinely points patients towards topical minoxidil for both sexes, and finasteride for men through private prescription or specific NHS pathways. Most other hair loss treatments are considered cosmetic and are not funded.
Can women use finasteride for hair loss in the UK?
Finasteride is licensed for men only in the UK. Some specialists prescribe it off label for postmenopausal women in specific cases, but it is not a first line option and is not safe in pregnancy. Spironolactone is more commonly used for female pattern hair loss.
What can I use to cover thinning hair while I wait for treatment to work?
Cotton-based hair fibres are the quickest fix. They bind to existing hairs to instantly fill the look of a thin patch or a widening parting, with no chemicals or commitment. Hair Guru London's fibres are cotton rather than keratin, which makes them gentler to layer alongside other treatments on the same scalp.