Arctostaphylos Uva Ursi Leaf Extract

Arctostaphylos uva-ursi (bearberry) leaf extract is used for brightening/antioxidant effects (often via arbutin and related phenolics/tannins) typically around ~0.1–2% in leave-on products. Botanical extracts—especially those containing tannins/phenolic compounds—show a measurable rate of irritant reactions on sensitive or eczematous skin in patch testing and real-world use, and can add cumulative irritation when combined with other actives (acids/retinoids). Given the variability in extract composition and the higher risk in compromised skin, I score it as moderate and recommend patch testing for reactive patients. Safety Notes: In commercial brightening and “spot corrector” leave-on products, Uva Ursi (bearberry) leaf extract is frequently used at very low levels (~0.01–0.1%) as part of multi-extract botanical blends where it serves as label-claim support rather than the primary active. Dedicated consumer brightening serums/creams sometimes use it as a key botanical active around 1–3%, and high-strength OTC formulations (typically leave-on) are observed up to about 5% extract, with higher levels uncommon due to color/odor, solubility, and irritation risk tied to arbutin-like phenolics; rinse-off products are generally at the lower end because of short contact time.