Retinoid + AHA
Keep them apartKeep them apart. A retinoid plus an AHA (glycolic, lactic, mandelic) at the same time can overwhelm your barrier - two proven actives, one irritated face.
You don't have to choose. Alternate nights (retinoid one night, AHA the next), or put the acid in the morning and the retinoid at night. Same ingredients, none of the pile-up.
A few things make this pair riskier: sensitive or rosacea-prone skin, strong acid concentrations, and starting both at once. Go slow, one new active at a time, and patch-test.
If you use an AHA in the morning, finish with SPF - exfoliated skin is more sun-sensitive.
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