Shop Skincare › L-Mandelic Serum L-Mandelic Serum from $40.00 An alpha hydroxy acid serum that contains the chirally correct versions of both l-mandelic acid and l-lactic acid. An alpha hydroxy acid serum that contains the chirally correct versions of both l-mandelic acid and l-lactic acid. Strength: Select Strength 5% 8% 11% Quantity: Add To Cart Added!