The rationale of this study is to establish a robust method for assessing sun protection product efficacy in preventing erythema and tanning. Employing both artificial ultraviolet-A Irradiation and natural direct sunlight exposure, the investigation seeks to provide a reliable methodology, ensuring reproducibility and enabling a direct comparison between these methods. Meticulously determining optimal UV dosages, the study prioritizes inducing skin responses for evaluation while avoiding adverse effects like blistering. The localized validation of UV exposure techniques, tailored to the Indian population, contributes significantly to the field by addressing diverse skin types and environmental conditions. By incorporating both artificial and natural (direct sunlight) UV exposure methods, the study aspires to enhance the safety and effectiveness of future dermatological investigations, benefiting both the scientific community and the broader population.

Inclusion Criteria:

1. 06 Healthy adult subjects aged between 18 to 45 years (both inclusive).
2. Healthy adult male and non-pregnant|non-lactating females.
3. Female of childbearing potential have self-reported negative urine pregnancy test.
4. Subjects with Fitzpatrick skin types III to V will be included. Alternatively, subjects with a Skin colorimetric Individual Typology Angle (ITA) value ranging from 20° to 41° at the application site (forearms) to be included to ensure a diverse representation of skin tones.
5. Absence of known photosensitivity disorders to maintain the integrity of the study outcomes.
6. Subjects must exhibit a willingness to comply with study plan, including follow-up visits and product applications.
7. No history of skin cancer to or any adverse skin conditions, and not under any medication(s) likely to interfere with the study results.
8. Subjects willing to follow study direction and willing to give written informed consent for the participation.

Exclusion Criteria:

1. Active skin diseases, such as eczema or psoriasis, that could potentially influence skin reactions.
2. Use of photosensitizing medications that interfere with UV-induced skin responses.
3. Pregnancy or breastfeeding status, as hormonal changes during these periods can affect skin reactions.
4. Individuals with a history of severe adverse reactions to skincare or cosmetic products, ensuring participant safety.
5. Presence of open wounds, infections, or cuts at the application sites to prevent complications during the study.
6. Subjects with a history of significant sunburns in the past three months, minimizing the potential for confounding effects.