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How to Shop for Retinol Serums Like a Pro

Written By Tyler Gaul 07 Nov 2019

Retinol (Vitamin A) and its derivatives ("retinoids," like retinyl palmitate and oxidated retinol) are the gold standard for reversing wrinkles and creating smooth, youthful-looking skin. However, because the skincare industry is considered by the FDA to be "cosmetic," there is very little regulation around what can be labeled as a "Retinol Serum" in the industry. Because of that, the most important thing to consider is:


Not all forms of retinol are created equal.

In fact, most forms are somewhere between a little irritating and totally unusable by your skin. When it comes to ingredient science, skincare companies generally like to keep people in the dark––so they can get away with using ineffective forms that are much easier to produce and bottle. In general, the dermatologists acknowledge three forms of retinol that are worthwhile. 

1) Pure Vitamin A (regular retinol)

Clinical effectiveness: Medium
Molecular stability: Low

Believe it or not, plain retinol is not the most common form of retinoid used in skincare products. This is because it is a very sensitive molecule that will degrade within weeks of exposure to oxygen or UV light. In addition, it must be converted by the skin twice (first to oxidated retinol (or retinal), then to retinoic acid) before it can be used. In that conversion process it is often also converted into a third "storage" form of retinol called retinyl palmitate. With all of this conversion going on, 1) much of the potency of the molecule is lost before it gets to your skin and 2) it creates the dry, inflamed reaction commonly associated with retinoids. Thus, though this is one of the better retinoids commonly available on the market, it is not the ideal solution for ongoing skin renewal. 

2) Prescription retinol (retinoic acid or tretinoin)

Clinical effectiveness: Very High
Molecular stability: Lowest

Prescription retinol usually comes in the molecular form of either retinoic acid or tretinoin. Both of these versions have 100% bioavailability, meaning they do not need to be converted by your skin at all to activate their skin-renewing powers. Thus, they will have by far the greatest impact on removing wrinkles and creating smooth, even, youthful-looking skin. However, because of this 100% bioavailability, prescription retinoids are also notorious for setting your skin ablaze and creating dry, inflamed, and even scaly skin during the renewal process. Thus, most clients have to slowly ease into using prescription retinol over a long period of time and few will ever get to where they can use it daily.  

2) Oxidated retinol

Clinical effectiveness: Very High
Molecular stability: Low

Originally discovered in 1944 by scientists who were researching the molecular components of eyesight, retinol in its oxidate form (sometimes called retinal, with an "a") is created when regular retinol (vitamin A) interacts with enzymes in the skin or body that precisely cut the molecule in two. This new form is the "precursor" to retinoic acid, and is thus easily converted into retinoic acid by the skin. However, because oxidated retinol is not 100% bioavailable, it is only influences a specific type of cell (keratinocytes) at a specific point in its lifecycle. These cells happen to be the most important cells in producing springy, youthful collage-filled skin and have the greatest impact on reducing signs of aging. Because of this, oxidated retinol's clinical impact is nearly identical to that of retinoic acid, but without the drying inflammatory response.

This is simply the most advanced, precise and effective form of retinoid on the market. But since it is equally as delicate as prescription retinol, few companies have even attempted to bottle it. Protocol has completely reinvented the formulation and bottling process using proprietary technology to allow oxidated retinol to be perfectly preserved in our airless and UV-proof bottle. 

Shop the Oxidated Retinol™ Serum here.


Further reading:

Journal of Cosmetic Dermatology, Mar 1, 2016, A comparative study of the effects of retinol and retinoic acid on histological, molecular, and clinical properties of human skin

Archives of dermatology., 1995 Sep;131(9):1037-44., Two concentrations of topical tretinoin (retinoic acid) cause similar improvement of photoaging but different degrees of irritation. A double-blind, vehicle-controlled comparison of 0.1% and 0.025% tretinoin creams.

Lancet (London, England)., 1993 May 8;341(8854):1181-2., First trimester topical tretinoin and congenital disorders.