Proper Doses of Retin-A Do Smooth Skin, Studies Find
TUCSON, Ariz. — The largest and longest study yet on the anti-aging effects of Retin-A confirms that the acne cream does smooth wrinkles, but reducing doses apparently reduces its effectiveness, researchers say.
“There is no question that the more you use, the more you improve,†said University of Arizona researcher Clayton Owens. “In those people who used the strongest doses, what we saw was a decrease in fine wrinkling, in roughness and in uneven coloring.â€
The University of Michigan found a year ago that Retin-A--a synthetic form of Vitamin A known as tretinoin, long used to treat acne--dramatically reduced the ravages of aging and sun damage in a short-term study of about 30 people.
Since then, nationwide studies have been under way on how well it works and whether it is safe. The federal government has yet to approve it for this use, but it is available by prescription from physicians.
Last year, the U.S. Food and Drug Administration issued a strong statement condemning indiscriminate use of Retin-A to treat wrinkles.
FDA Commissioner Frank E. Young said there is no conclusive evidence that the drug reduces wrinkles. “Long-term animal studies and well-controlled clinical trials involving larger numbers of patients in various age groups are needed to assess the risks and benefits,†he said.
Significant Side Effects
The Michigan study used a high dose of the drug, and patients suffered significant known side effects of Retin-A: peeling, burning, redness and overall irritation of the skin.
A six-month study of more than 300 patients last year at the University of Arizona, Duke University, New York University and the University of Minnesota used lower and varying doses of the drug to learn whether side effects could be eased while still getting the positive anti-aging effects, Owens said.
Divided into four groups, the 300-plus patients used daily doses of Retin-A ranging from the highest tretinoin concentration of 0.05, to a moderate dose of 0.01, to a weak dose of 0.001, to a zero-dose in the placebo group. The Michigan study used concentrations twice as high, at 0.10 strength.
Nearly 90% of patients using the 0.05 dose showed at least some improvement, with half showing moderate to strong improvement, Owens said. Those using lower doses showed some effects of the Retin-A, but the results were much weaker and “questionable,†he said.
The patients in the study were from 50 to 70 years old and were chosen because they showed moderate, not severe, signs of sun-damaged skin: mostly fine, but also some coarse wrinkling, also blotchy coloring and rough texture.
All of these factors were visibly and statistically rated, as were the side effects. In addition, the length and depth of wrinkles were measured in plastic impressions, and skin biopsies were analyzed microscopically.
Patients used the Retin-A daily, along with sunscreens and moisturizers.
“The biggest improvement was in the skin pigment, in evening out the skin’s color and getting rid of blotches and brown spots,†Owens said. “The next biggest improvement was in fine wrinkling--the cross-hatches below the eye and in the crow’s-feet area. After that, we saw improvement in texture--in smoothing out rough skin.â€
There was also some improvement in deeper, coarser wrinkles in some patients, but since that problem was not prevalent in most of the patients, it was difficult to measure that impact scientifically, he said.
Owens also said the side effects of Retin-A were less than expected.
Some Peeling, Redness
“Most people had mild to moderate side effects--mostly peeling and some redness. By and large, the side effects were tolerated well. Usually, the effects would last a few days, then go away, then come back for a few days. After a few months, the skin seems to get used to the drug. Only three or four people had constant irritation, but nobody had any serious problems.â€
So what is the best dosage of Retin-A to halt the ravages of time?
“I know this will sound like a cop-out,†Owens answered. “But that is something that has to be determined between the patient and the doctor. People react differently to the stuff. The doctor has to assess your skin type. He will know when the irritation is too much, and if you are using enough to get good results. That is why Retin-A will remain a prescription drug for some time.â€
