Retinoids, AHAs and salicylic acid: what sources say

Three ingredient groups come up together in routines: retinoids, alpha hydroxy acids (AHAs) and salicylic acid. This page says what DermNet NZ and the FDA say about each. It does not say which one anyone should use.

Retinoids

DermNet describes topical retinoids as medications derived from vitamin A, in cream, lotion, foam, emulsion or gel form. It says retinol and retinaldehyde are commonly added to cosmetics, while prescribed ones include adapalene, tazarotene, tretinoin and trifarotene.

DermNet lists these side effects and risks:

• Retinoid dermatitis, meaning redness, peeling and dry skin.
• Irritant contact dermatitis.
• Sun sensitivity.
• Allergic contact dermatitis, which it calls rare.
• A potential risk in pregnancy, particularly with widespread tazarotene use.

DermNet also says retinoids can be irritating close to the eyes or lips, and can make eczema worse because of their drying effect. It says adapalene is the least irritating topical retinoid and tretinoin the most. It describes applying them at bedtime, with a sunscreen and moisturizer combination during the day.

Alpha hydroxy acids

The FDA says the most common AHAs in cosmetic products are glycolic acid and lactic acid. It says AHA products cause exfoliation, or shedding of the surface skin, and the extent depends on the type and concentration of the AHA, its pH and other ingredients.

The FDA says AHAs may increase skin sensitivity to the sun. It recommends label wording that says to use a sunscreen, wear protective clothing and limit sun exposure while using the product and for a week afterwards. In FDA-run studies, sensitivity to UV-caused skin reddening rose by 18 percent after four weeks of AHA use. The FDA says the increase is reversible, with no significant difference one week after use stopped.

The cosmetic industry’s review panel concluded that products with glycolic and lactic acid met its conditions when the AHA concentration was 10 percent or less and the pH was 3.5 or greater, and the product protected skin from sun sensitivity or told users to use daily sun protection. The FDA reports this; it is not an FDA finding.

Salicylic acid

The FDA says salicylic acid is the BHA most commonly used in cosmetics, and adds that from a chemist’s view it is not a true BHA. For products with BHAs, the FDA says to:

• Test on a small area of skin before applying to a large area.
• Stop and consult a physician if irritation or prolonged stinging occurs.
• Follow the label and not exceed the recommended applications.
• Avoid BHA products on infants and children.
• Use sun protection.

Using them together

DermNet’s page on salicylic acid says not to use these on the affected area unless a doctor directs it: other medicated topical agents such as benzoyl peroxide and topical retinoids, and cosmetics or soaps designed to peel or exfoliate. It also says to tell your doctor if you are pregnant or breast-feeding, because salicylic acid can be absorbed through the mother’s skin.

DermNet notes that some topical retinoids are contraindicated in pregnancy. If this applies to you, talk to a doctor or pharmacist.

What Poliage shows

Poliage flags ingredients by CosIng INCI name. The Retinoids flag covers vitamin A forms such as retinol, retinal and retinyl esters, plus tazarotene. The Salicylic acid flag covers salicylic acid and its salts and derivatives. A flag says Contains, then the ingredient and its function. It states what is listed, not a judgment. Check the label on the pack. Poliage gives product information, not medical advice.

Where this comes from

The retinoid details come from the DermNet NZ page on topical retinoids. The AHA details come from the FDA page on alpha hydroxy acids. The BHA advice comes from the FDA page on beta hydroxy acids. The combination and pregnancy statements come from the DermNet NZ page on salicylic acid. All were read on 2026-10-22.