Scientists confirmed: rosemary extract really does help skin heal without scarring

A study by scientists from the Perelman School of Medicine at the University of Pennsylvania has found that a compound found in rosemary leaves actually promotes wound healing without scarring. The work is published in the journal JCI Insight.

The scientists found that the key active ingredient is carnosic acid, a powerful antioxidant that helps switch the skin repair process from scar formation to full tissue regeneration.

"Many skin injuries end in scarring, which can cause not only aesthetic but also functional problems. Our results show that rosemary extract can direct healing along a healthy pathway, which has not been previously achieved in humans," said study leader, dermatologist Thomas Leung.

Interestingly, the idea for the experiment was born thanks to social media. Student at the University of Pennsylvania Jiay Peng and graduate student Emmanuelle Rapp Reyes noticed that users actively share recipes for home remedies with rosemary and brag about the improvement of skin condition. They decided to see if there was real science underneath it - and went to the lab.

Scientists made a cream based on carnosic acid and tested it on mice. The results exceeded expectations: the skin healed faster, and in place of wounds restored hair follicles, sebaceous glands and even cartilage tissue. At the same time, the treatment did not cause irritation or inflammation.

The team also found that the effect of rosemary is associated with the activation of a special receptor TRPA1, which has previously been associated with the body's ability to scarless healing. In mice deprived of this sensor, the effect of the cream completely disappeared.

Scientists tested other plants - thyme and oregano also affected TRPA1, but rosemary proved to be the most effective and safe. In comparison, known stimulants of this receptor, such as mustard oil or the drug imiquimod, often cause skin irritation.

Importantly, the effect was observed only when the cream was applied topically - if it was applied to intact areas of the skin, wound healing was not accelerated. This indicates that the mechanism of rosemary works strictly at the site of damage.

Scientists warn: despite the encouraging results, it is too early to draw conclusions about the use of rosemary in home cosmetics. Before using such products should consult a doctor. However, due to the plant's low cost and availability, the researchers hope that in the future it could be used to treat wounds in humans, especially those prone to rough scarring.

"If you use rosemary in your skincare routine and you see the effects - it may well be real," said Professor Leung. - "I am proud that young scientists have found a scientific explanation for observations from everyday life."