Salmon sperm to bird droppings: The science behind bizarre skincare trends A flurry of bizarre beauty therapies are trending on social media. But does the scientific research suggest they can be taken at face value? A flurry of bizarre beauty therapies are trending on social media. But does the scientific research suggest they can be taken at face value? At the You & I Clinic in Seoul, South Korea, one of the most requested skin texture treatments involves injecting tiny fragments of DNA from salmon sperm into the dermis, the skin's thick middle layer which houses the blood vessels, nerves and glands. "The goal is not volume, like a filler, but skin priming or biostimulation, which involves supporting a healthier dermal environment and recovery," says Kyu‑Ho Yi, an aesthetic physician at the clinic and an adjunct professor at Yonsei University.and wound healing, where DNA fragments from fish gained attention for their potential to stimulate tissue repair in people with facial scars from combat injuries.suggest that the treatments – which harness the salmon sperm's purified polynucleotides – may help reduce the appearance of fine lines. They've been shown "to help improve skin hydration, plumpness, texture and wrinkles", says Joshua Zeichner, associate professor of dermatology at Mount Sinai Hospital, in the US, who has also worked for skincare companies as a consultant. "It's unclear how someone first decided to try this as a skin treatment, but nonetheless, it's being used." With South Korea now viewed as a trendsetter in aesthetics – otherwise dubbed as the K-Beauty craze – the supposed benefits of salmon and other fish sperm injections have spread around the globe, encouraged by a flurry of celebrities. Their popularity has risen alongside a collection of other odd-sounding treatments, which include facemasks made of bird droppings and blood-sucking vampire facials.A quick glance through the history books shows that skincare has a long and storied history of seemingly odd practices. The Egyptian queen Cleopatraa paste known as thanaka to their faces for centuries, made from ground tree bark, both as a decorative practice, and to shield their skin from sun damage.Yet modern skin science suggests that at least a few of these ancient beauty therapies have stood the test of time, with ingredients likeexamined various skincare practices from 12th-Century Italy that had been cited in the writings of a famed female medieval medical practitioner called, are now considered to be effective for facial cleansing, exfoliating, and treating dry skin. An extract of tartar oil called tartaric acid, for instance, isIt's not just plants, herbs and minerals found in nature. The so-called "Geisha Facial" involves taking excrement from nightingale birds, sanitising it using powerful ultraviolet light, mixing it with other chemicals such as an exfoliant and a brightener, before applying it like a face mask. This coprocentric techniquethat the droppings of Japanese bush warblers, a type of nightingale, could be used as a dye remover in fabrics. This then led to the droppings being used by Japanese female entertainers for skin whitening and removing their heavy makeup. Nowadays, it's popular in various clinics around the world as a way of brightening the skin, and again, there could be some sound science behind it. According to Zeichner, nightingales leave particularly high concentrations of urea in their droppings, a chemical with suchto have hydrating and brightening benefits," says Zeichner. "But it's important to say that these use purified, modified nightingale droppings. You shouldn't just scoop up bird poop off the street and rub that onto your face." Another important point to note here is that many studies into these treatments have been funded by the beauty industry or conducted by scientists directly employed by these companies. Researchers are less enthused, however, about another supposed DIY skincare treatment which has been doing the rounds on TikTok, namely menstrual masking – or period blood face masks. Whilesuggested that plasma derived from menstrual fluid might be capable of enhancing wound healing, compared with regular blood plasma, Beibei Du-Harpur, a dermatology researcher at King's College London, isn't convinced. "No clinician would ever recommend that," says Du-Harpur. "I think this is just one of those TikTok trends which has emerged because of the shock factor and people wanting to get views."Du-Harpur is more optimistic about the potential of platelet-rich plasma injections, sometimes dubbed the "Vampire Facial", for skin rejuvenation. This procedure involves taking the patient's own blood and using a centrifuge to separate it into fractions. This process helps to concentrate the numbers of growth factors – a special group of proteins which instruct cells to grow, divide and repair – in the plasma, before injecting the blood back into the facial skin using microneedles.Some of the trending skincare routines are more rooted in the science than others The potential of harnessing the body's own growth factors in a regenerative fashion is generating active interest across various areas of medicine, from"There's quite a lot of variability in how successful PRP is for people," says Du-Harpur. She says that this is due to differences in the machines used for the centrifuge process, and because some people might have higher or lower concentrations of growth factors, or different types ofWhile even the most bizarre of skincare routine fads may have some scientific backing, scientists think that options for the next generation of skincare therapies will involve, among other things, finding new ways to optimise collagen supplementation.used supplements with amino acids that had been specially engineered for collagen replacement. It elicited not only improvements in skin texture, hydration, and elasticity over the course of six months, but also an average reduction in biological age of 1.4 years, according to DNA tests on the patients' saliva. The researchers concluded that collagen supplements containing this particular balance of amino acids could potentially not only improve skin health, but also other aspects of health.that the skin has a hitherto under-recognised role in the body's overall health, through processes such as inflammation, but the study still concluded that a lot more research is required on the processes involved. on a facial for a one-time improvement in hydration and glow, Zeichner would much prefer someone stick to a consistent routine with sunscreen in the morning to protect the skin from environmental damage, he says. 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