Cos De Baha — L1 Bakuchiol 2% · Retinol 0.15% Serum 30ml

Cos De Baha's L1 is built around a well-thought-out progression logic: 0.15% retinol (≈ 4,950 IU) introduces the skin to retinoids without triggering the intolerance reactions frequent with higher concentrations. At this dose, anti-aging effects are measurable but develop gradually—which is exactly what one looks for in a first-time use. 2% bakuchiol is combined for its action on the same RAR/RXR receptors via a distinct signaling pathway. A word of caution here: the reference clinical studies (Dhaliwal et al., BJD 2019 — Bluemke 2022) validated 0.5% bakuchiol in isolated use, never in combination with retinol in a finished product. The synergy is therefore mechanistically plausible but not clinically demonstrated, and the 2% concentration used here is about 4 times higher than the studied doses: we are extrapolating on the ingredient; nothing can be stated about the combined formula. 400 ppm adenosine is a recognized cosmetic active for its action on fibroblasts and smoothing. 2% niacinamide is modest but contributes to retinol tolerance and skin tone uniformity. Points of vigilance: the presence of Lavandula angustifolia and Rosa damascena in the INCI introduces a risk of sensitization for reactive skin via natural fragrance allergens (linalool, geraniol, citronellol — Annex III of EU Regulation 1223/2009); the "Fragrance Free" badge sometimes displayed by the brand does not correspond to this INCI and is not endorsed. For phototypes IV-VI, the introduction of retinol—even at a low dose—must be even more gradual due to the risk of reactive post-inflammatory hyperpigmentation. Absolute contraindication during pregnancy and breastfeeding. The serum is the right entry point before a possible progression to L2 (0.5%) then L3 (1%) for skins that wish to advance over time.