Acne serums typically target pH 3.5-5.5 to support the skin barrier and enhance active penetration. Salicylic acid serums work best at pH 3-4 for beta hydroxy acid efficacy. However, very low pH risks irritation; a skilled formulator balances pH with buffering agents and soothing ingredients. Use a pH meter during development. The AJ Cosmo Labs app connects you with chemists who optimize pH stability.
Read the full guide on how to formulate a serum for acne prone skin →