Ulva Lactuca Extract

Ulva lactuca (sea lettuce) extract is typically used at low concentrations as a soothing/antioxidant and humectant-supporting botanical, and it is not inherently pH-active or keratolytic. Clinical experience and patch-test data for seaweed-derived extracts generally suggest good tolerability, but—as with many botanicals—there is a non-zero risk of irritation or sensitization in highly reactive or eczematous patients due to complex polysaccharide/protein fractions and potential trace contaminants. Given this low but real risk in compromised skin, it fits best as a generally well-tolerated “gentle” ingredient rather than exceptionally gentle/inert. Safety Notes: In mass-market leave-on skincare, Ulva lactuca (sea lettuce/green algae) extract is commonly used at very low levels (often via a diluted supplier solution) around 0.0005–0.05% active to support marketing claims and add antioxidant/soothing positioning without impacting odor/color or stability. Mid-range serums/creams and masks more typically land around 0.1–1% active extract. High-strength consumer products marketed as “algae/seaweed concentrates” (leave-on ampoules/serums, some wash-off masks) can reach ~2–5% depending on extract type (glycerin/water vs powder) and sensory/stability constraints; higher levels are uncommon due to tackiness, marine odor, and color shift.