By Dr. Asnat Raziel, specialist in obesity treatment, metabolic health and healthy longevity; Director of the Multidisciplinary Center for Obesity Treatment, Assia Medical, Assuta Ramat HaChayal
Urolithin A for skin: the main finding
Urolithin A for skin is a new direction in research on skin aging. Most people know urolithin A as a supplement for muscle and mitochondrial health. Now a study published in the journal iScience has tested it as a cream. In women aged 50 to 75, a cream with 1% urolithin A reduced wrinkle depth around the eyes compared with placebo after 8 weeks. It also reduced redness caused by UVB radiation.
What is urolithin A?
Urolithin A is a compound that gut bacteria make from substances in fruits and nuts, such as pomegranates, berries and walnuts. However, not everyone produces it. A study of pomegranate juice drinkers found that only about 40% of people produced meaningful amounts of urolithin A. That is why companies have developed it as a ready-made supplement.
In particular, the compound activates mitophagy, the process in which a cell breaks down and replaces damaged mitochondria. For context, mitochondria are the cell’s “power plants.” With age they work less well, and this is one of the key mechanisms of aging.
What do we know about urolithin A as a supplement?
In recent years researchers have tested urolithin A in several human trials. The first human trial showed it was safe and changed markers of mitochondrial function. Later, a trial in adults aged 65 to 90 showed better muscle endurance and lower levels of CRP, a marker of inflammation. However, the trial’s main goals, such as walking distance, did not improve. The picture looked similar in a trial in middle-aged adults: muscle strength improved, but the main goal was not met. The new study asks a different question: does the compound work directly on the skin?
Urolithin A for skin: how researchers built the study
The study had three parts. First, a safety test in 112 volunteers aged 19 to 65. The researchers applied the cream to the skin under patches again and again, and there was no irritation or allergy.
The main part was a randomized, double-blind, placebo-controlled trial. It included 48 women aged 50 to 75 with visible crow’s feet. Then each woman applied the active cream to one side of her face and an identical cream without the compound to the other side. One group received a 0.5% concentration and the other 1%. The researchers measured wrinkle depth with 3D imaging.
The third part tested protection from sun damage, and 21 volunteers completed it. The researchers exposed an area on the back to UVB radiation and then applied the cream for 24 hours.
Urolithin A for skin: what the results showed
After 8 weeks, the 1% concentration reduced wrinkle depth around the eyes compared with placebo. The difference was statistically significant, but only just (p=0.04). In contrast, the 0.5% concentration had no significant effect.
In the sun test, the 1% concentration reduced redness by 13% compared with exposed, untreated skin. Here too the lower concentration did not help. The researchers also took small skin samples from the arm and examined gene activity. In the treated area, genes linked to collagen production became more active. At the same time, genes linked to inflammation and cellular aging became less active.
A note of caution: the study’s limits
There are several reasons for caution. First, the study was small and short, just 8 weeks. Second, only the higher concentration worked, and the wrinkle difference was borderline. Third, all participants in the wrinkle trial were fair-skinned women, so we cannot easily generalize the results.
In addition, this is industry research. Amazentis, which markets urolithin A, funded it. Some of the researchers are company employees, and others work for the cosmetics companies L’Oréal and Lancôme. No independent study has yet repeated the results. Finally, the study measured cosmetic outcomes, not long-term skin health.
Urolithin A for skin and your skincare routine
This is an interesting direction because it targets a biological mechanism of aging, not just the skin’s surface. Even so, there is no reason to give up the basics. The best protection against skin aging is still daily sunscreen, not smoking, good sleep and a plant-rich diet. You can read more about the science of aging and what longevity medicine offers today. It is also worth remembering that healthy longevity starts from within: a healthy weight, regular exercise and metabolic balance, as I explain in my article on fitness for longevity.
The bottom line
A first placebo-controlled study shows that a cream with 1% urolithin A reduced wrinkles around the eyes and reduced redness from UVB radiation. The results are promising, but they come from a small study funded by the manufacturer. We should wait for larger, independent studies before recommending it as a treatment.
The information in this article is general only and is not a substitute for personal medical advice. For questions about your own health, please consult your doctor.
Sources
Amazentis funded the study; some of the researchers are employees of the company and of L’Oréal and Lancôme. The Hebrew version of this article is available here.
