Browse the Internet or supermarket shelves, and it seems there are a growing number of products for restoring thinning locks.
Hairfluencers abound, touting serums, sprays, oils and foams that contain a baffling array of ingredients, such as rosemary, saw palmetto and caffeine.
They make bold statements, claiming to reduce hair loss, prevent thinning, stimulate the scalp and boost growth… but do they? What hope is there for those who worry they are losing their hair? And what new treatments are in the offing?
Hair loss (known scientifically as alopecia) is remarkably common. Around 80 per cent of all men and 50 per cent of all women experience some sort of hair loss at some point in their lives.
Some take it in their stride, but for many, hair loss is a source of significant stress and anxiety. Playing to this theme, the global hair loss treatment industry is estimated to be worth around $8.85bn (approx. £6.71bn).
“The internet is full of things you can spend your money on,” says Prof Desmond Tobin, from the Charles Institute of Dermatology, University College Dublin, who chairs Alopecia UK’s research committee. But, he says, the area is “ripe for snake oil interventions.”
Here’s everything you need to know about hair loss treatments – and how the latest research could offer a more permanent solution.
The root causes of hair loss
We all have around 100,000 hairs on our scalp, and we all lose around 100 to 150 hairs per day. This is completely normal. Each hair fibre sits in its own hair follicle, where it grows in a three-stage cycle.
During the active phase, which lasts for around two to eight years, the fibre grows slowly and steadily, at a rate of around a centimetre per month (so, an inch in two and a half months).
This is followed by the transitional phase, lasting a week or so, where the follicle shrinks. Then, during the resting phase, which takes a few months, the hair fibre falls out and the cycle starts again.
Hair loss only becomes noticeable when the amount of shedding significantly exceeds the amount of regrowth.
Lots of things can cause this, including, sometimes, certain medical conditions. Actor and producer Sharon Stone, for example, lost hair on the sides of her head after she suffered a stroke, while actor and activist Alyssa Milano shared her experience of losing hair after a bout of COVID-19.
Hair loss causes stress, but stress can also cause hair loss. Around twenty years ago, researchers showed this definitively in animals, but in the last few years, they’ve managed to explain the mechanics behind it.
Stress hormones act on particular cells at the base of the hair follicle, where they suppress the activity of a gene that regulates hair growth.
As a result, follicles spend more time in the resting phase, and less time in the active phase of the hair cycle. When hair loss exceeds hair regrowth, balding occurs.
Genetics can play a role, as can hormones. There are lots of different types of alopecia and, sometimes, it’s caused by the hair follicles becoming more sensitive to male sex hormones in the body. This makes the follicles shrink and eventually stop producing hair.
It can happen to both men and women, leading to male-pattern baldness (where the temples recede and the crown thins) and female-pattern baldness (where the hair becomes generally sparser).
In some cases, the immune system is involved. Alopecia areata (AA) occurs when immune cells mistakenly attack the hair follicle.
The condition, which affects 1 in 1,000 people, is the most common autoimmune disease in the world, and leads to patches of hair loss which can grow and join together. Women, men and children can be affected.
An 'emerging epidemic' of hair loss among women
Frontal fibrosing alopecia is another type of hair loss, which causes the frontal hairline to recede in a straight line. It was first noted in the nineties, when six cases, all post-menopausal women, were reported in Australia.
Since then, numbers have grown substantially, and although the overall incidence is relatively low – around 1 in 10,000 – researchers have spoken of an ‘emerging epidemic.’
“It’s now so common in dermatology clinics that you can’t miss it,” says dermatologist Prof Andrew Messenger, who has seen many cases at the Sheffield Teaching Hospital.
Genetics has been implicated, as has the immune system, but Messenger thinks that environmental factors could be important too.
Noting a correlation between people with FFA and the use of facial products containing sunscreen, he claims that UV filters could be to blame.
“The timing certainly fits,” he says. UV filters were routinely added to moisturisers from around the year 2000, he says, after which, cases of FFA took off. Also, women use these products more than men, especially around their face and hairline, which could explain why FFA mainly affects women.
For now, however, the idea remains a theory, so while researchers learn more about the causes of FFA, don’t stop using your sunscreen. It has proven benefits against skin cancer.
Meanwhile, if you are worried about hair loss, of any type, choose your products wisely, and consider speaking with a healthcare professional for guidance.
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Where to turn if you start losing your hair
Hair loss treatments fall into two broad categories: those which can be bought over the counter, and those which need to be prescribed.
“There’s a real mixture of evidence out there,” says Tobin.
As a general rule of thumb, shop-bought products are associated with less evidence and lower quality evidence (meaning these studies are either not randomised, lack control groups or don’t reveal information on the concentration of the ingredients tested) than prescription products, which have passed muster in clinical trials and have a more rigorous evidence base.
Often, the companies that sell us shampoos and serums run ‘consumer’ rather than ‘clinical’ trials, where people try their products and tell them what they think, typically without any scientific measurement.
This leads to statements like “80 per cent agreed their hair looked thicker” – which may sound impressive, but don’t necessarily mean much. How much thicker? A little bit? A lot? This is subjective, rather than scientific.
Furthermore, “people who feel they’re doing something often have a reasonable placebo effect,” says Tobin. Meaning: either they think their hair is thicker, when it’s not, or their hair really does become thicker, but not because of anything in the product.
Using a treatment that you think will work may lower your stress levels, which could help with regrowth.
All about minoxidil as a hair-loss remedy
So, what of all the ‘science-y’ sounding ingredients inside shop-bought products? To simplify matters, there is minoxidil, and then there is everything else.
Minoxidil was once prescription-only for hair loss, but then the patent expired, and it became available over the counter. This means there are lots of clinical trials to demonstrate its potential impacts.
Applied to the scalp as a liquid or foam, minoxidil has been shown to help promote hair growth in male- and female-pattern hair baldness and alopecia areata (AA).
The treatment is thought to work by increasing the blood supply to the follicle, but it takes around six months of daily treatment to have an effect, and it doesn’t work for everyone.
“About 30 per cent get some regrowth,” says Tobin, which can be “good, moderate or disappointing.”
Hair loss treatments popular on social media
In contrast, many of the hair loss trends on social media focus on natural ingredients.
Rice water can be used as a rinse, and castor oil can be massaged into the scalp, but there’s no scientific evidence to suggest that either would lead to growth.
Aloe vera can be applied as a gel, but clinical trials are lacking, and some of those who’ve tried it have experienced burning and irritation.
Rosemary oil has been studied in a couple of clinical trials. In one, from 2015, 100 patients with male-pattern baldness saw some regrowth that was on a par with minoxidil.
Meanwhile, topical caffeine has been tested in a number of trials, but while there’s some evidence for regrowth here too, the quality of these studies is low.
So, for both rosemary and caffeine, the data is limited, and the jury is out.
Over-the-counter hair loss products
Certain over-the-counter products also contain ingredients, such as saw palmetto, which are touted as ‘DHT blockers.’ DHT is the male sex hormone that can cause hair follicles to shrink.
One of the few prescription drugs used to successfully treat male hair loss, known as finasteride, is a tablet that works by reducing DHT levels.
There’s a big difference, however, between finasteride’s carefully formulated, precisely quantified active ingredient and the uncharacterised, unquantified natural ‘alternatives’ found in certain shop-bought treatments.
In other words: we know finasteride’s chemical structure, and we know the exact dose inside each tablet. We don’t know what the active ingredient is in, for example, saw palmetto, and we don’t know the concentration that’s being delivered to the scalp.
The take-home message, then, is that although some shop-bought products may work a bit for some people, it’s hard to know what you’re getting, or if it will work at all.
And remember, Tobin says, that sometimes hair can regrow on its own – so on a personal level, it’s hard to know whether any treatment is actually working or whether it’s just your own body’s doing.
Trying to reboot your immune system
Prescription medications, on the other hand, are underpinned by high-quality evidence from well-designed clinical trials. These include finasteride and also drugs that manipulate the immune system.
In 2014, Dr Claire Higgins, who now works at Imperial College London, was part of a team that showed AA occurs when immune cells, called cytotoxic T cells, migrate into the hair follicle, and activate a signalling pathway known as JAK/STAT.
When mice with a version of AA were treated with drugs that block this pathway – so-called JAK inhibitors – their fur regrew.
“Longstanding alopecia areata was reversed,” says Higgins.
This led to clinical trials. JAK inhibitors were pitted against placebo treatments to see if they could improve hair loss in people with AA.
They did. A review of 30 different studies, involving 289 people, found that three-quarters of those who took them experienced some hair regrowth.
Now there are two JAK inhibitors – baricitinib and ritlecitinib – licensed for the treatment of AA in the UK.
“The impact of regrowth there is quite substantial,” says Tobin, but he cautions that “still less than half get cosmetically acceptable regrowth.”
In addition, there are concerns that taking these immune-suppressing tablets for long periods of time could make people more vulnerable to infections.
Microneedle patches on the scalp
So, researchers are developing other options. Prof Natalie Artzi is a chemical engineer at Brigham and Women’s Hospital, which is part of Harvard Medical School in the US.
Her team have developed a microneedle patch that sits on the skin and can deliver drugs directly to the hair follicles and surrounding area.
The patch is made from a flexible hydrogel, covered in hundreds of tiny cone-shaped needles, that penetrate the skin without triggering the pain receptors deeper down. “It’s like a smart band-aid,” she says.
In a mouse study, the team loaded the hydrogel with two biological molecules, designed not to suppress the immune system, but to rebalance it.
The molecules attract helpful immune cells, known as T regulatory cells, to the area, where they can then quash the activity of the unhelpful cytotoxic T cells. This stops the immune system from attacking the follicles.
Applied every other day for three weeks, to the bald patches of mice with a type of AA, the smart band aids caused their fur to regrow. Then, when the treatment was stopped, the new growth kept going.
“It grew until it was full density,” says Artzi. “You couldn’t tell where the bald area was.”
This is a marked difference from other treatments, such as minoxidil and JAK inhibitors, where the hair loss often returns when the treatment is stopped.
“This is because we are treating the root cause of the disease,” says Artzi.
There is also less concern about making people vulnerable to infections, because the immune system is not being suppressed.
Now, Artzi is co-founding a company, Lybra Bio, to scale up manufacturing of the patch and test it in clinical trials.
Antibody therapy for treating alopecia areata
Another approach being trialled for AA is antibody therapy. Dupilumab is an antibody drug that is used to treat allergic conditions, such as eczema. It is given as an injection under the skin, and it works by lowering levels of pro-inflammatory molecules called Immunoglobulin E (IgE).
People with AA often have high levels of IgE in their blood, and around half of them also have a family history of allergic conditions, such as eczema.
So in 2022, Prof Emma Guttman-Yassky from the Icahn School of Medicine at Mount Sinai, in the US, and colleagues ran a clinical trial to see if dupilumab can reverse the symptoms of AA.
After 24 weeks of treatment, hair loss stabilised. After 48 weeks, two-thirds of those receiving the weekly antibody injections had varying degrees of hair regrowth.
Levels of skin inflammation were lowered, while the activity of genes involved in the production of keratin – the core structural component of hair – was increased.
“I’m very excited about dupilumab,” says Guttman-Yassky.
New growth for frontal fibrosing alopecia
As for frontal fibrosing alopecia (FFA), with its characteristic ‘hair band’ pattern of hair loss, the future is promising too. “For a long time, FFA was considered untreatable,” says Guttman-Yassky.
Like AA, the condition is thought to occur when the immune system attacks the hair follicle. Unlike AA however, in FFA, the hair follicles – and the hair-generating stem cells they contain – were thought to be permanently destroyed. Then the tissue just scars over.
Guttman-Yassky has shown, however, that not all of the stem cells are lost. Some remain and are capable of generating new hair if only they can receive the right signals.
So, she set up another clinical trial, this time to test the effect of a JAK inhibitor called brepocitinib.
When the drug was taken as a tablet for 48 weeks, it reduced inflammation in the scalp and prompted the hairline to start regrowing. “We saw some impressive improvement in some, but not all of the patients,” she says.
Time, it seems, is of the essence. Treatment was most effective in the early stages of the disease, before any scars had formed.
“If you’ve had FFA for two or three years, you have a chance to regrow your hair in full and I think that’s amazing,” she says. And for those who come to the treatment later, there is a chance, at least, to halt its progress.
So, the outlook is promising. Hair loss can be a stressful experience. Now, as new drugs are tested, and new ways of delivering them emerge, finally, the misery of unwanted baldness looks set to come to an end.
About our experts
Prof Desmond Tobin is a professor of dermatology from the Charles Institute of Dermatology, University College Dublin in Ireland. He also chairs Alopecia UK’s research committee. He is published in various scientific journals including Journal of Tissue Viability, Journal of Wound Care and Journal of the American Academy of Dermatology.
Prof Andrew Messenger is a semi-retired dermatologist and has been a consultant at Sheffield Teaching and Children's Hospitals. He has been published in the likes of British Journal of Dermatology, Dermatology and Therapy and SKIN The Journal of Cutaneous Medicine.
Dr Claire Higgins is a dermatologist and an associate professor of tissue regeneration at Imperial College London, in the UK. She is published in Experimental Dermatology, Nature Medicine and Proceedings of the National Academy of Sciences of the United States of America, to name a few journals.
Prof Natalie Artzi is a chemical engineer at Brigham and Women’s Hospital, which is part of Harvard Medical School, in the US, where she is an associate professor of medicine. She's been published in the likes of Nature Reviews Bioengineering, ACS Nano and Nature Biomedical Engineering.
Prof Emma Guttman-Yassky is a professor of dermatology and immunology at the Icahn School of Medicine at Mount Sinai, in the US, where she is also the Health System Chair. She is published in scientific journals such as Archives of Dermatological Research, JID Innovations and Journal of the American Academy of Dermatology.
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