In other DermTV episodes I’ve discussed that Retin-A is not compatible with some other exfoliants because of the brittle nature of Retin-A… meaning that it’s so easily broken or inactivated by other chemicals, especially acids. But time and time again, viewers specifically ask about whether they can use Retin-A and glycolics. The short answer is yes, and I’ll explain when you can and when you can’t, but I’d also like to ask, why would you want to?
First, glycolic acid, the gold standard of chemical exfoliants, is sufficiently powerful to inactivate Retin-A if applied at the same time, regardless of which is applied first. You’ll get the benefit of the glycolic, which isn’t compromised by the brittle Retin-A, but most probably the Retin-A will be inactivated. Fortunately that does no harm to your skin; it simply cancels out the benefit of the Retin-A.
But you can use both Retin-A and glycolic acid in the same skincare regimen as long as they are applied hours apart from each other, such as Retin-A in the morning and glycolic at bedtime. That allows Retin-A to work without interference. And yes, I said Retin-A in the morning…. The increased sun sensitivity from Retin-A is cumulative and occurs after many days of use and doesn’t depend on what time of the day you use it. So as always, sunscreen is a must.
But my bigger question is, why would you want or need to use both glycolic and Retin-A. Very simply, adding Retin-A to a regimen already using therapeutic levels of glycolic is unlikely to add any additional efficacy and merely increases the potential for retinoid irritation, sun sensitivity or other side effects much more common with retinoids than glycolics. There isn’t anything that Retin-A does that glycolic doesn’t.
If your glycolic isn’t achieving adequate exfoliation in two to four weeks, Retin-A still isn’t the answer. It just means it’s time to increase the strength of your glycolic. For people without sensitive skin, I believe that the therapeutic starter strength of glycolic is 8%. My patients usually progress, as needed, from 8% to 10% and finally to 15% glycolics, to achieve in office results at home.
Now don’t get me wrong. In the 80s, I used Retin-A with my patients because it was the best exfoliant available at the time. But after glycolic was introduced, I made the switch and have never looked back. For more beautiful, healthier and younger looking skin, my vote is glycolic, and so is my patients’.