Retinoids are known for being one of the gold standard topical acne treatments—I often prescribe them to my patients. But I’ve noticed there seems to be a lot of confusion out there about how to use retinoids properly, especially in conjunction with other popular active ingredients like vitamin C and benzoyl peroxide. If you’re like some of my patients, you may have heard that you should only use retinoids at night or that they can degrade quickly in your medicine cabinet. Both are true to an extent and, complicating matters even further, you want to be very careful when combining these powerful vitamin A derivatives with other products—in this case, you really can have too much of a good thing. Here are a few pointers that will help you become a retinoid ace, whether you’re a beginner or a skincare pro.

When should I use retinoids for acne?

In the past, many have recommended using retinoids only at night due to sunlight causing the formula to degrade. The question on whether or not you can only use retinoids at night has created some confusion because our advice has changed slightly. While first generation retinoids like tretinoin were not photostable, nowadays, there are a number of prescription retinoids that are photostable. This means they have been formulated in a way that they don’t degrade in the presence of sunlight. Those include adapalene, tazarotene, trifarotene, and even tretinoin, as long as it's in the micronized form or formulated with microspheres. You can use those during the day for everything from helping to soften fine lines [1] to fading hyperpigmentation [2] to, yes, helping treat acne. [3] But, as always, make sure you’re using a sunscreen as well. 

OTC retinol acne products are different though

My advice changes, however, if you’re using an over-the-counter retinoid like retinol, retinol ester, or retinal, which is a different derivative of vitamin A than the kind a doctor can prescribe. Most of the over-the-counter retinols are mostly likely not photostable, so if you're buying a retinol cream for acne off the shelves, use it before bed. Then, if you’re using, or have been prescribed, another active ingredient to fight acne like glycolic acid or salicylic acid, you can use that product in the morning. 

What about benzoyl peroxide and retinoids?

Benzoyl peroxide is another commonly used ingredient to fight acne. I tend to recommend that my patients use BP in the morning if for no other reason than it can bleach your sheets and pillowcases. If you’re also using an OTC retinol acne product in conjunction with a benzoyl peroxide cream or lotion, go ahead and use the former at night and the latter during the day. Prescription retinoids for acne are a different story altogether—they can be stronger that their OTC counterparts, so I’d definitely want you to consult with your dermatologist before combining retinoids for acne with a topical benzoyl peroxide.  

So what’s the best way to use vitamin C?

First, if you’re not using a product with vitamin C here’s why you might want to consider it: Research suggests it’s a strong anti-inflammatory that brightens and helps your skin produce new collagen. [4] It’s also an antioxidant that may help to scavenge skin-damaging free radicals generated by the sun.

As for when to use it, that's an interesting question: There are studies that suggest applying vitamin C in the morning in conjunction with a good sunscreen can help protect your skin from UV damage better than the SPF alone. [5] That’s why it may be more beneficial to use a product with vitamin C as part of your morning regimen, making sure you layer a non-comedogenic sunscreen with an SPF of 30 to 50 on top. 

You can use vitamin C and retinoids 

But, please, proceed with caution. These are powerful ingredients, so start by alternating them until you can see how your complexion tolerates the combination—one day, use your vitamin C in the morning, the other, use your prescription retinoid in the AM or your retinol at night. If you decide to give it a go, I have a request: Make sure you use an extra-gentle non comedogenic cleanser without additional active ingredients so you’re not over-stripping your skin and upping your chances of irritation.

References:

[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2699641/

[2]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2921758/

[3]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5574737/#:~:text=The%20AAD%20states%20“retinoids%20are,a%20recent%20study%20of%20prescribing 

[4]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3673383/

[5]: https://www.sciencedirect.com/science/article/pii/S1087002415305128