Retinoids, Retinols, and Retinoic Acids, Oh My!
Okay, technically retinoids are a large class of chemical compounds related to vitamin A. Retinol and retinoic acid (Retin A®) are both types of retinoids, but you will often hear of retinoids as the products you need a prescription for, and retinols as those sold over the counter. Our bodies can convert retinol into retinoic acid, but it takes a while. So the over-the-counter products can do what the prescription products do, but significantly more slowly.
Common Prescription Retinoids
*tretinoin, (the generic name for retinoic acid) including Retin A®, Avita®, and Renova®;
*adapalene (Differen®), and
The gentler, slower, over-the-counter retinoids (retinols) have too many trade names to list.
For our purposes we will refer to all topical vitamin A products as retinoids. But remember, while all topical vitamin A products are retinoids, not all retinoids are topical. Isotretinoin is a retinoid that is administered orally. (See the articles about Accutane)
Retinoids are used to treat acne, dark spots, sun damage, wrinkling, rough skin texture, and other signs of aging. Of all the anti-aging ingredients to have been developed over the last 80 years, only retinoids have consistently, clinically, proven their value, but they were originally developed as a treatment for acne!
Vitamin A has been known since the 1940s to be an essential vitamin for the nutritional health of the skin. Early research showed vitamin A could stimulate new cell growth in the skin and produce a softer, smoother appearance. The early experiments had subjects consume the vitamin orally. But taking the amount necessary to visibly change the skin soon created the side effects of vitamin A toxicity – everything from hair loss to liver damage to softening of the skull!
In the 1970s scientist began focusing on topical applications of a vitamin A cousin, retinoic acid (they originally called it vitamin A acid) with remarkable results, and the enormous industry of retinoids was born.
Retinoids work in two ways.
First, when formulated to penetrate the outer layers of the skin, they produce rapid skin cell growth. Normally the skin takes 28 days from first formation of a cell in the basal layer of the epidermis until it is sloughed off. Retinoic acid speeds this process up to 14 to 16 days. It also stimulates the formation of more collagen and blood vessels in the dermis, thickening and plumping the skin in the process.
Second, retinoids also have an exfoliating effect, causing more rapid shedding of the outer layer. The outermost layer of the epidermis, which scientists call the stratum corneum, is normally 14 layers of densely packed skin cells. The use of topical retinoic acid sloughs off several of these cell layers, thinning the stratum corneum to eight or nine layers of more loosely woven skin cells.
The combination of the rapid regeneration of cells and the sloughing of the outer cell layers results in the peeling away of dark spots and the exfoliation of acne impactions or comedones. Over time these actions improve acne, soften the skin, lift dark spots and reduce the appearance of wrinkles.
Combat Skin Irritation
The downside of this little miracle worker is that it can be highly irritating to the skin. It can cause redness and visible peeling that is quite uncomfortable, and frankly, unsightly. People on prescription retinoids have asked me, “How long will it make me ugly before it will make me beautiful?”
To combat the irritation, some manufacturers have formulated retinoids in various creams, in hopes they would be more soothing, but the creams produce other problems. The vitamin A binds to the creamy ingredients, rendering it unavailable to the skin. Many ingredients in cream formulations are pore clogging, counteracting the benefit the product has for acne. The cream form of Retin A® contains isopropyl myristate, and if you’ve read the pore clogging article, you know that it is perhaps the most comedogenic product of all time.
The best solution for the irritation caused by most retinoids is a gradual break-in schedule to allow your skin to adapt without becoming irritated. Start with low dosages worn only two nights a week. First wash with a mild cleanser and allow the skin to dry for 15 minutes. Letting it dry is important because retinoids cause more irritation when applied to damp skin. Even if it feels dry to the touch, it is important to let more than just the very outer layer dry. Then apply only a pea sized amount of the retinoid, avoiding the eye area and lips. If the skin is still tacky after application, you have used too much product. Wait another 15 minutes to allow the product to absorb into the skin. Then apply a high-quality, non-clogging moisturizer. If you apply the moisturizer too soon, the vitamin A can bind to it and not work on your skin. This sounds more complicated than it is!
After two to three weeks of this regimen, if there is no irritation, increase the wearing schedule to every other night for three weeks to a month.
If there is irritation don’t increase the schedule until the skin has had a chance to normalize. But also check for other sources of irritation that may be interacting with the retinoid. Are you using a space heater or other hot air source that may be drying out your skin? Do you point your hair dryer toward your face while drying your hair. Over-dried skin is much more susceptible to irritation from the retinoid. Heat sources like these are also a culprit in creating or worsening dark patches on the skin, particularly skin of color, so eliminate them.
Also check your moisturizer, or anything else you are using on your skin, including make-up, for irritating ingredients.
Products you have been using without irritation before the retinoid may actually have mildly irritating ingredients that only cause you a problem in combination with the retinoid. Don’t give up on the retinoid. It is a very valuable and beneficial skin treatment. Get rid of the other sources of irritation.
If there are no other sources of irritation, back off a little on the retinoid, but keep using it. If you are consistent with the level just below irritation, your skin will adjust and you will be able to increase.
After a month of every other night with no irritation, increase to two nights on, one night off, for another month. If you still have no irritation, go to every night for a month. Then you can go up to the next level of potency and start again with two nights a week.
Only wear retinoids at night, as sunlight makes them highly unstable. Always wear a good sunscreen during the day, because your skin will be more sun-sensitive due to the exfoliation. But you were wearing that anyway, weren’t you?
Don’t Let Retinoids Inflame Skin
Like Benzoyl Peroxide, retinoids are a valuable tool in overcoming acne, but when applied without proper guidance, the cure can be as bad as the disease. Retinoids should not be allowed to inflame your skin to achieve the results you are seeking.
Scientists have created many variations of retinoic acid, in an attempt to make it less irritating to the skin and therefore easier to use. Almost none have been completely successful. The challenge is a Goldilocks problem: when creating esters of vitamin A, either the molecule is too large to be able to penetrate the outer skin to reach the part where the activity must take place, as in the case of vitamin A palmitate, or it is so small that it recrystallizes out of the solution necessary for application, as is the case of vitamin A acetate.
The Baby Bear answer comes to us in a lesser known retinoid cousin called vitamin A propionate which is an ester of vitamin A and propionic acid. Vitamin A propionate has the molecular weight and configuration to be transdermally deliverable (it can get to the part of the skin that can use it) and stable in solution. Interestingly enough, vitamin A propionate was developed by the very man, James E Fulton, Jr. MD, PhD, who originally developed Retin A®. He is perhaps the foremost acne researcher in the world today, and he was determined to overcome the irritation of his original invention.
Dr. Fulton designed his vitamin A propionate product to take skin type into account, and so there are various levels and different protocols depending on the type of skin being treated. It works as rapidly as Vitamin A acid, but with far less irritation. Due to the lower irritation factor, a prescription is not required, but due to the variation according to skin type, it is only dispensed through skin care professionals.