Comedogenic checker

Non-comedogenic is a label word that means the product is made so it will not clog pores. The American Academy of Dermatology (AAD) tells people with acne to look for sunscreen that says "non-comedogenic" or "won't clog pores", and to pick a mild cleanser with the same words on the label. The word describes the finished product. The rabbit ear grades in this checker describe single ingredients.

Comedogenic ingredients are ones that caused plugged pores, called comedones, in lab tests. In Fulton's 1989 rabbit ear study, isopropyl myristate, isopropyl isostearate, myristyl myristate, laureth-4 and oleth-3 got the top grade of 5 out of 5. Lauric acid, cocoa butter and acetylated lanolin alcohol got 4. These grades come from animal tests of single ingredients. Paste a label above to see each grade and its source.

In Fulton's 1989 rabbit ear table, cocoa butter and coconut butter scored 4 out of 5, and sesame, corn, avocado, soybean, evening primrose and cottonseed oil scored 3. Safflower and sunflower oil scored 0. The paper says results for oils depend on the source, and refined sesame, avocado and olive oil scored lower. Morris and Kwan (1983) gave sweet almond oil 3, and olive and avocado oil 0.

Coconut oil has no grade under that name in the two rabbit ear tables this checker uses. Fulton's 1989 table lists "coconut butter" at 4 out of 5, a grade the paper counts as positive, and says results for all oils depend on the source of the raw material. The table does not say whether its coconut butter matches the coconut oil in your product, so the checker shows coconut oil as "no published rating found".

Ethylhexyl palmitate scored 4 out of 5 in Fulton's 1989 rabbit ear table, a grade the paper counts as positive. Morris and Kwan (1983) tested "octyl palmitate" and gave it 2 to 3. The checker keeps the two apart, because PubChem, the chemical database of the US National Institutes of Health, lists octyl palmitate and 2-ethylhexyl palmitate as two different compounds. The amount in a product also changes the effect.

Jojoba oil scored 0 to 2 out of 5 in Fulton's 1989 rabbit ear table, and the paper marks this result as depending on the source of the raw material. Fulton wrote that for beeswax and jojoba oil, "some commercial preparations are more comedogenic than others." That study counted a grade of 0 to 1 as not significant and 2 to 3 as borderline. Sulfated jojoba oil scored 3.

Glycerin scored 0 out of 5 for pore clogging and 0 for irritation in Fulton's 1989 rabbit ear table, the lowest grades on the scale. Propylene glycol and sorbitol also scored 0 in the same table. A 0 is still a lab result for one ingredient tested at 10 percent on a rabbit's ear. Your skin may react to a finished product in its own way, so a patch test helps.

Dimethicone scored 1 out of 5 for pore clogging in Fulton's 1989 rabbit ear table, and that paper counts a grade of 0 to 1 as not significant. Cyclomethicone scored 0 and simethicone scored 1. Fulton wrote that "the silicones and sterols do not appear to be a problem." A 2014 review of acne moisturizers in the Journal of Clinical and Aesthetic Dermatology also called dimethicone noncomedogenic.

Plain lanolin scored low in both rabbit ear tables: 0 to 1 out of 5 as anhydrous lanolin in Fulton's 1989 study, and 0 in Morris and Kwan's 1983 study. Some lanolin derivatives scored 4 or more. Acetylated lanolin alcohol scored 4 in 1989 and 4 to 5 in 1983, and PEG-16 lanolin scored 4. Fulton linked the acetylated lanolin alcohol result to its cetyl acetate additive.

Comedogenic means able to cause comedones, the plugged pores seen as blackheads and whiteheads, and a tiny plug inside a pore is the earliest sign of acne. In 1972, Kligman and Mills described "acne cosmetica", a low-grade acne in adult women linked to cosmetics. A 2006 JAAD study by Draelos and DiNardo tested products on people and concluded that finished products made with comedogenic ingredients are not always comedogenic.

Comedogenic effects are real in lab tests: rabbit ears treated with some ingredients formed plugged pores that researchers measured under a microscope. How well this predicts human skin is less certain. In 1984, Fulton's group called the rabbit ear an imperfect model and the best one they had. In 1989, Fulton wrote that it "still remains uncertain" whether high-scoring ingredients always clog pores in people.

Castor oil scored low in both rabbit ear tables. Fulton's 1989 table gave it 1 out of 5, a grade that paper counts as not significant, and says results for oils depend on the source. Morris and Kwan's 1983 table gave undiluted castor oil 0 to 1. In the 1989 table, hydrogenated castor oil scored 1 and PEG-40 castor oil scored 0.