Saccharomyces Lysate

Saccharomyces lysate is a yeast-derived ferment/lysate used in low concentrations as a skin-conditioning, barrier-supporting, humectant-like ingredient, and it is generally well-tolerated in clinical and consumer use. However, because it contains a complex mixture of yeast cell components, it has a small but real risk of irritation or allergy in highly reactive/atopic individuals compared with truly inert excipients. Scoring it as gentle (0.3) reflects its typically low irritancy while acknowledging sensitization potential in compromised eczema-prone skin. Safety Notes: In commercial skincare, Saccharomyces Lysate (a yeast-ferment/lysate skin-conditioning ingredient) is often used at low supportive levels around 0.05–0.5% in mass-market moisturizers, cleansers, and toners where it functions as part of a broader “ferment” complex. Most leave-on serums/essences that feature ferments more prominently tend to fall ~1–5% active lysate (or lysate equivalent), while high-strength consumer “ferment/biome” concentrates and ampoules can reach about 10% where odor, color, and stability/compatibility constraints become limiting. There is no specific FDA/EU maximum limit for this INCI; practical formulation and sensory constraints typically set the upper bound, and both rinse-off and leave-on products use it with higher levels more common in leave-on concentrates.