You can determine if sunscreen is working effectively by observing the following: No Sunburn: If you don't experience sunburn, it's an indication that the sunscreen is providing protection against UVB rays. No Skin Sensitivity: If your skin is not becoming red or irritated after sun exposure, it suggests that cruelty-free sunscreen is providing adequate protection against UVA rays. Even Skin Tone: Sunscreen products help prevent uneven skin tone and hyperpigmentation. No Tanning: If your goal is to maintain your current skin tone, using a high-SPF sunscreen should help prevent tanning.