Mandelic Acid (AHA)

Mandelic acid, extracted from bitter almonds, is the largest of the common AHAs — roughly twice the molecular size of glycolic acid. Its slow penetration translates into exceptionally gentle exfoliation with a significantly lower risk of post-inflammatory hyperpigmentation, which makes it the AHA of choice for darker skin tones and reactive complexions. At 5–10% it refines texture, unclogs pores, and has documented antibacterial activity against acne bacteria. Mandelic acid is also more photostable than other AHAs and pairs well with other actives. Results build gradually over weeks of consistent use. Evening application two to three times weekly, followed by moisturiser and daily SPF, is the proven protocol.