Does light break down tretinoin (Retin A) cream?

Dear Dr. Bailey,

If I put tretinoin 0.025% cream on a half hour after I cleanse, and then wait around in very low light (TV or computer) for several hours before I go to bed, is the tretinoin breaking down/degrading from that low light?

Thanks for your answer, ‘Cura’

Dear ‘Cura’,

Wow, I really like how you are thinking through the details of your tretinoin therapy.  This is a question that is actually quite complex.  The short answer is that quite possibly the visible light from light bulbs may degrade Retin A to some extent.  Just how much and how quickly is impossible to know because it depends on the output of your light bulbs.

The tretinoin in Retin A cream is very prone to inactivation by light.  UVA breaks it down the most but the peak wavelength that does this is 420nm, which is just into the visible light spectrum right outside of the UVA wavelength spectrum. This means that visible light from light bulbs can break down your tretinoin.  So can sunlight with its visible light rays, UVA and UVB rays.

I recommend to my patients that they apply their tretinoin as the last thing they do before going to sleep. Most of us sleep in the dark and this takes care of the light/tretinoin issue.  I keep my tretinoin on my bedside table for that purpose.

It’s also important to wear a broad spectrum sunscreen that reliably blocks both UVA and UVB during the day to keep light out of your tretinoin treated skin. I prefer the mineral sunscreen agents for this job and recommend only reputable sunscreen products with at least 5% or more micronized zinc oxide.  The mineral sunscreens basically sit as a particle shield on the outer surface of the skin and prevent light from passing through to any of the skin layers.

This is a very well thought out question.  I hope I’ve been able to help.

Warm Regards,

Cynthia Bailey MD, Dermatologist

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If you found this information helpful, you may also want to read:

How To Correctly Use Retin A (Tretinoin) For Acne and Anti Aging Skin Care

Start the Best Anti Aging Skin Care Now and See Results In the New Year

How To Pick The Best Sunscreen


Int J Pharm. 2008 March 20; 352(1-2): 123–128.

UVA is the major contributor to the photodegradation of tretinoin and isotretinoin: implications for development of improved pharmaceutical formulations
Bassam M. Tashtoush,1 Elaine L. Jacobson,2 and Myron K. Jacobson2*

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3 Responses to “Does light break down tretinoin (Retin A) cream?”

  1. Cura Pelle January 20, 2011 at 4:08 pm #

    I suppose the only kind of radiation coming at me from the computer screen or TV is of the electromagnetic variety. So, I should be alright. I can’t afford the Replenix right now, so I try to have the tretinoin on my skin for a couple of hours, then pat it with water and put on some olive oil such that I have a few hours of direct tretinoin-skin contact and then some moisturizer.

    A dermatologist prescribed me Retin-A at 27 when I had no real problems, just dryness from washing with soap and water and using no moisturizer or sunscreen. I thought I knew better, so I went with his other recommedations but passed on the Retin-A. Now, I’m making up for lost time. Shucks! I could’ve been augmenting my collagen already!

  2. Joshua Powell January 31, 2011 at 4:57 am #

    Hi Dr. Bailey,

    I’m curious as to why the product information leaflet for my Retin-A gel (brand-name, from Ortho, UK) states to apply it twice daily? Surely they wouldn’t suggest applying it in the morning if it were broken down? The product information leaflet in Retin-A Cream (also brand name, from Ortho) in Australia says exactly the same thing too.

    It has me puzzled, as I have always believed light broke down the active ingredients.



  3. Cynthia Bailey MD January 31, 2011 at 1:40 pm #

    I can not explain this package information. The data on tretinoin photo-degradation is clear. It can also cause a sun light induced redness on the skin when light hits the product as it sits on the skin and this can add to tretinoin intolerance. The US product information is clear about applying the product at night before retiring. You pose a very curious question. I would recommend that you ask the company. Thanks for bringing this to my attention. Very interesting…..
    Warm Regards, Cynthia Bailey MD