A cream containing vitamin A managed to reduce wrinkles significantly in elderly people, scientists report.
Ageing skin is more frail
Not only did the cream make skin appear more youthful, tissue samples from 23 people revealed it boosted levels of important skin repair chemicals.
Michigan University Medical School experts described their findings in the journal Archives of Dermatology.
Robust scientific research supporting the claims of many "anti-ageing" creams is hard to obtain.
As people age, their skin produces less collagen, as a result becoming thinner and less smooth.
This is not the first study to support the use of vitamin A creams to improve the appearance of ageing skin.
Earlier this year, a favourable report from Manchester University scientists on a "No.7" cream, screened as part of a BBC Horizon documentary, caused stores to run out of the product within days.
The Michigan team do not say which particular cream they used, only that it contained a "retinol", or vitamin A component.
They recruited 36 people with an average age of 87 and, over a 24-week period, asked them apply the retinol cream on the inner arm on one side, and a cream with no active component on the other.
After the 24 weeks, the skin appearance was assessed, and a small sample taken for analysis.
Underarm skin was chosen because it suffers less exposure to the sun, which can accelerate skin ageing.
Not everyone finished the study, and it was assumed by the researchers that the 13 people who dropped out had not seen any benefits in how their skin looked.
However, even with this added in to the results, there was a significant improvement between the retinol and non-retinol arms.
The small skin samples taken supported this - showing an increase in the production of glycosaminoglycan and procollagen, two skin components, in the samples exposed to retinol.
One of these is thought to improve the appearance of skin by retaining extra water and "plumping" it up, while the other is a basic building block of skin structure, so could in theory be helping repair it.
In addition, there may be other benefits to the elderly person aside from vanity - the researchers believe that their rejuvenated skin samples might be better able to withstand damage and less susceptible to ulceration, a frequent problem for older people in poor health.
"Safe and effective therapies to reverse the atrophy of natural skin aging do not exist currently," they wrote.
"Topical retinol improves fine wrinkles associated with natural aging."
A spokesman for the British Skin Foundation said a type of vitamin A cream, known as Tretinoin, was already prescribed by dermatologists to treat skin ageing.
"They work by improving the topmost layers of the skin, increasing cells production and helping to increase collagen which gives the skin its structure."
She said that shop-bought creams might be less effective, because they have a lower concentration of the active ingredient compared to those available from dermatologists.