Maybe this article from futurederm.com will help you understand alcohols:
The Most Misunderstood Skincare Ingredient: Alcohol
All too often, consumers will refuse to buy a product because it contains high concentrations of some form of alcohol. Yet, according to Dr. Audrey Kunin, board-certified dermatologist and founder of DERMAdoctor.com, not all alcohols are dry and irritating. In fact, according to Kunin, there are seven dense alcohols — cetyl alcohol, cetearyl alcohol, cetostearyl alcohol, cetyl alcohol 40, C12-15 alcohols, stearyl alcohol and lanolin alcohol — that are not drying or irriating. Instead, these agents are used in products as emulsifiers, thickening agents and stabilizers, allowing skin care products to have silky-smooth formulations. In addition, lanolin alcohol and stearyl alcohols also act as moisturizing factors, so not only are they not drying, they are moisturizing.
Is lanolin an allergen?
Because lanolin is derived naturally from the sebaceous glands of sheep, lanolin has often been thought of as an allergen or sensitizing agent. However, according to Begoun, a 2001 study in the British Journal of Dermatology found that the mean annual rate of sensitivity to the allergen amongst 24,449 patients was only 1.7%, with a 50% concentration of lanolin. Lower concentrations of lanolin would most likely result in even lower rates of sensitivity. As such, lanolin alcohol, an emollient derived from lanolin, should not act as an allergen or sensitizing agent in most individuals as well. If you have a known allergy to sheep’s wool or any reservations, you should consult your dermatologist.
Which alcohols are safe in skin care products?
An easy way to remember these alcohols when shopping: the 5 “C” alcohols, and “steer left,” where “steer” stands for stearyl alcohol and the “l” in “left” for lanolin alcohol. An additional note: It may be noted that cetyl, cetearyl, cetostearyl and cetyl alcohol 40 are all derived from coconut oil, and so they should not be used by anyone with coconut allergies.
So how did alcohol achieve its poor reputation?
According to Paula Begoun, author of Don’t Go to the Cosmetics Counter Without Me, low molecular weight alcohols are often drying and irritating in skincare formulations. In addition, according a CNN article on skin care, the Mayo Clinic states that moisturizing products containing low molecular weight alcohols are not as effective because they evaporate quickly from the skin. The low molecular weight alcohols most commonly found in skincare products are (the first three are the same, under different names): ethanol, ethyl alcohol, denatured alcohol, methanol, benzyl alcohol, isopropyl alcohol, and SD alcohol. (Denatured or “SD” means that the alcohols are processed so that they cannot be ingested.) The five different agents are used as a solvent, antiseptic, or degreasing agent in skin care formulations. When found high on the ingredients list, they can be drying and irritating. However, according to Kunin, if the ingredient is contained lower in the ingredients list, they may simply be acting as a degreasing agent, making for a better texture of the skin care formulation.
What does alcohol consumption do to the skin?
Excessive alcohol consumption damages skin in two primary ways. One, alcohol will dilate the blood vessels, leading to telangiectasias or chronic dilation of the capillaries, and a flush of the face. Under increased pressure, the stretched vessels may break, appearing as broken capillaries on the face. It may also be noted that it is known that alcohol consumption aggravates symptoms of patients with rosacea.
Two, alcohol interferes with the body’s processing of vitamin A (including retinoids). According to Stryker et. al, the consumption of alcohol leads to a reduced absorption of vitamin A from the diet. Because vitamin A is a known antioxidant with anti-aging properties, decreasing its absorption may lead to advanced aging. In addition, retinoids may not be as effective following excessive alcohol consumption, as Leo and Lieber note there is competition between ethanol and retinoic acid precursors, leading to accelerated breakdown of retinol through the cross-induction of degradative enzymes. With retinoids available for less time in the system, it is highly probable less efficacy is achieved, and more probable that the retinoids produce toxic by-products. The latter was verified by Leo and Lieber, as ethanol promotes the toxicity of both vitamin A and ß-carotene in the body. The researchers thereby caution that discretionary (reduced) amounts of vitamin A and ß-carotene are used by drinking populations to decrease the risk of toxicity in the body. No studies to date have been done investigating the efficacy and toxicity of topical retinoids in combination with alcohol consumption, so ask your dermatologist if you are concerned.
The Bottom Line?
Alcohols that are safe to use are the 5 C’s and “steer left” (stearyl and lanolin alcohols). Other lower-molecular weight alcohols may not be drying or irritating if they are found low on the ingredients list. Alcohol consumption leads to increased flushing of the skin, decreased absorption and efficacy of vitamin A, and increased toxicity of vitamin A and ß-carotene, so be aware of excessive alcohol consumption when using products that contain vitamin A. The bottom line: for improved skin appearance, don’t be as scared of alcohol in your skin care regime (using the guidelines above), but be fearful of excessive alcohol in your glass.
