Cos De Baha — G Glycolic Acid 10% Serum 30ml

Sérum G is the AHA exfoliant from the Cos De Baha range. 10% glycolic acid is the AHA with the smallest molecular weight (76 Da) — this characteristic allows for effective epidermal penetration and keratolytic action on intercorneocyte bonds. At 10%, it is just at the limit recommended by the SCCS (2023 opinion) for leave-on facial AHAs, in the zone of significant exfoliation without reaching the levels of professional peels (30-70%). Arginine, a basic amino acid, is incorporated to buffer the final pH — this is a clever formulation approach that allows for progressive acid release and improves skin tolerance without sacrificing efficacy. The final pH is not communicated by the manufacturer (SCCS limit = pH ≥ 3.8 for leave-on AHAs) — for very reactive skin, a prior patch test is recommended. The 12-ingredient formula is exceptionally clear: no superfluous active ingredients, no fragrance, no potentially sensitizing extracts. Points of caution: glycolic acid is photosensitizing — exfoliated skin is more permeable to UV for 24 to 72 hours after application and in the following days. A morning SPF 50+ is non-negotiable and must be maintained even on days without serum. Do not combine on the same evening with a BHA, retinol, or another exfoliant — risk of cumulative irritation and barrier weakening. On phototypes IV to VI, 10% AHAs can trigger post-inflammatory hyperpigmentation — proceed very cautiously (1 application per week at start). Pregnancy: conditional — consult a healthcare professional; 10% AHAs are not recommended as a first choice during this period.