Apply sunscreen first or apply primer first?

In general, primer (or sunscreen base) is less irritating to the skin and can be applied directly onto the skin. It serves to protect the skin from radiation and damage caused by other cosmetics. Sunscreen, on the other hand, is relatively more irritating to the skin and mainly protects against damage from ultraviolet (UV) rays. Therefore, it is usually recommended to apply primer first, followed by sunscreen. Both primer and sunscreen provide protection against UV rays in sunlight. Moderate sun exposure allows UV rays to promote the conversion of vitamin D in the body and facilitate calcium absorption. However, excessive sun exposure can damage the skin. UV rays may cause skin redness, swelling, and pain, and in severe cases, can even lead to skin cancer. Thus, if prolonged exposure to sunlight is unavoidable, it is important to take protective measures for the skin. Applying primer first followed by sunscreen can provide double protection. If after prolonged sun exposure, the skin develops abnormal symptoms such as swelling, pain, or redness, it may be necessary to visit a dermatology clinic for medical evaluation and treatment.