Excessive exposure to ultraviolet (UV) radiation can cause skin damage, premature aging, and skin cancer. This study aimed to formulate and evaluate a marine herbal sunscreen stick using Kappaphycus alvarezii, zinc oxide, and natural ingredients such as beeswax, shea butter, coconut oil, carrot seed oil, and vitamin E. The prepared formulations were evaluated for physical appearance, pH, spreadability, antioxidant activity, anti-inflammatory activity, and Sun Protection Factor (SPF). The optimized formulation showed good physical properties, satisfactory spreadability, a skin-friendly pH (6–7), 56% antioxidant activity, 61% anti-inflammatory activity, and an SPF value of 15. The results indicate that the marine herbal sunscreen stick provides effective UV protection and has promising antioxidant and anti-inflammatory properties. Therefore, it may serve as a safe and eco-friendly alternative to conventional sunscreens.

Objective: To formulate and evaluate a marine herbal sunscreen stick containing Kappaphycus alvarezii and natural ingredients for photoprotective efficacy.