Nannochloropsis Oculata Extract

Nannochloropsis oculata extract is a microalgae-derived skin-conditioning/antioxidant ingredient typically used at low concentrations in leave-on products, and it is not a classic primary irritant like acids, retinoids, or surfactants. However, as a complex botanical/algal extract containing multiple bioactive molecules (proteins, pigments, lipids), it carries a small but real risk of irritation or allergic-type reactivity in highly sensitized or eczema-prone patients. Given limited robust clinical irritation datasets compared with more standardized actives, I rate it as generally gentle but not inert. Safety Notes: In mass-market leave-on products (serums, creams, eye products), Nannochloropsis oculata extract is often used as a minor “marine/algae” supporting active at ~0.0005–0.05% due to typical supplier dilutions (e.g., extract-in-glycerin/butanediol) and cost/odor/color constraints. Mid-range formulations commonly land around ~0.1–1% when the extract is a marketed feature, especially in anti-aging/firming leave-on products. The upper end (~3–5%) is observed in consumer-available “high-algae” gels/ampoules/masks and some rinse-off cleansers where higher loading is feasible, noting that at very high levels the INCI may represent a diluted extract rather than 100% dry biomass.