When I turned 40 with barely a handful of grey hairs, I felt rather smug. I assumed my naturally red locks were destined to stay youthful indefinitely.
How wrong I was. Four months ago, I celebrated my 46th birthday, and while tying my hair into a ponytail, I noticed white strands appearing everywhere.
I had spotted the occasional grey before, but suddenly they seemed to be spreading across my entire head, particularly around the sides.
Some women are perfectly comfortable embracing their changing colour. I am not one of them.
My red hair is closely tied to my identity, so the prospect of losing it to grey felt surprisingly difficult to accept.
Apparently, the only reliable way to deal with stubborn greys is to book regular, expensive appointments with a colourist. So far, that is a route I have avoided.
That is why I was intrigued when K18 FutureIQ Biomimetic Hair Longevity Serum arrived on my desk. The product claims to ‘reverse’ grey hair and even prevent new grey strands from appearing.
As a beauty editor, I am wary of such ambitious promises. However, I have tested other products from American biotech haircare brand K18 and have been impressed. Its Airwash dry shampoo, for example, has become a firm favourite.
Bethan King says her red hair is part of her identity, making the prospect of losing it to grey feel particularly difficult
Testing the serum therefore seemed worthwhile, especially after reading hundreds of positive reviews on the company’s website and examining its relatively small clinical study. Of the 71 participants, 70 per cent had fewer grey hairs after applying the serum nightly for three months.
Potential miracles do not come cheaply. A 90ml bottle costs £110 (k18hair.co.uk) and is intended to last for one month. If it delivers on its promise, however, that still works out cheaper than a monthly visit to my high-end London colourist.
So what is behind the formula? It includes a blend of biomimetic peptides, designed to imitate naturally occurring messenger amino acids that support the cells responsible for producing hair pigment.
The serum also contains unspecified antioxidants, which are said to protect the follicles from oxidative stress caused by factors including pollution and UV exposure—both of which may contribute to greying.
Alongside these ingredients is a patented ‘root-anchoring’ complex. Its exact components have not been disclosed, but the brand says it helps limit shedding linked to the breakdown of root proteins within the follicles. In theory, using the serum every day should encourage new growth in your natural colour while reducing hair loss.
Those are impressive claims, but there is an important qualification. The serum is said to work best for people with less than 30 per cent grey coverage. Once hair is mostly grey, many follicles may no longer contain enough melanin reserves for the treatment to make a visible difference.
K18 provides a useful online guide for estimating grey coverage. According to its calculations, I am around 10 per cent grey, meaning I appeared to be a suitable candidate. The greys on the top of my head, where my hair is naturally lighter, blend in fairly well. The darker hair at the back and sides is a different matter.
I had also noticed that my hair was becoming thinner—courtesy of the perimenopause—so I was hoping the serum might help with that, too.
Before using the serum, Bethan estimated that about 10 per cent of her hair was grey—below the 30 per cent level at which the treatment is said to work best
After three months, Bethan could barely see any greys around the back and sides, where a noticeable cluster had previously appeared
The brand recommends using the treatment for three months before assessing the results. With a 90-day supply costing £330, I began applying it every night. It can be used on either wet or dry hair.
I was surprised by the quantity required: four pipettes are recommended to cover the scalp. At first, I worried that applying the serum to dry hair would leave my roots looking oily.
Thankfully, the fragrance-free formula is watery and absorbs within minutes, leaving no residue or marks on my pillow. By the end of the three months, I had not noticed any obvious change in my hair colour during the treatment, although my hair did feel slightly thicker.
Fortunately, any beauty editor worth her salary takes ‘before’ photographs. When I compared them with my ‘after’ images, I was genuinely surprised by what I saw.
The greys around the back and sides, where there had previously been a sizeable cluster, were barely visible. The roots and mid-lengths also appeared to have lost their grey cast.
The grey hairs have not vanished entirely, but there are definitely fewer of them—and I am thrilled with the difference.
But is this truly a breakthrough product? Experts urge caution.
Samantha Stewart, a consultant trichologist at The Spencer Clinic, says further clinical research is needed to establish how a serum of this kind works, particularly because greying can have several different causes.
‘Any response is likely to vary from person to person,’ she says.
‘It depends on the extent of someone’s grey hair, their natural colour, how long they have been grey and, importantly, what caused it to begin. Genetics can influence both the age at which greying starts and how quickly it progresses, while oxidative stress may also play a role.’
She adds that nutritional deficiencies, including low levels of vitamin B12, iron or copper, can also be responsible. ‘These factors do not affect everyone in the same way, so for a product like this to work, it would need to address the processes responsible for the loss of hair colour in the first place.’
Regarding my own results, Ms Stewart says longer-term monitoring would be necessary to establish the serum’s true impact. ‘Any positive effect you experienced would be difficult to assess over such a short period, and several factors could account for the change in appearance,’ she says.
I have not made any lifestyle changes over the past three months, though, so I am inclined to think the serum is having an effect. For now, I have no plans to stop using it.
My hairdresser offered the most reassuring feedback. Just last week, she asked whether I had started dyeing my hair at home because it looked ‘less ashy’. If a professional can see a difference, I am happy to count that as a success.
