Three claims worth checking
SPF mainly describes protection against UVB under test conditions. Broad-spectrum means the product also covers UVA. Water resistance tells you how long the tested protection lasts during water exposure; it does not mean waterproof. The AAD recommends broad-spectrum SPF 30 or higher and a water-resistant formula.
Application changes the result
A strong number on the tube cannot compensate for a thin or missed application. The AAD says most adults need around one ounce to cover exposed body skin, with at least a teaspoon for the face. Apply to ears, neck and other uncovered areas too. Reapply about every two hours outdoors and after swimming or sweating, following the bottle's directions.
Choose the formula you will wear
Texture and finish affect whether a person uses sunscreen consistently. For dark-spot concerns, a tinted formula with iron oxides may help with visible light. Sunscreen is one part of protection: shade and protective clothing reduce exposure as well. If a product stings or causes a rash, stop using it and ask a clinician about alternatives.
Frequently asked questions
What SPF should I use daily?
The AAD recommends SPF 30 or higher with broad-spectrum protection.
Does water resistant mean waterproof?
No. Water resistance has a tested time limit, and sunscreen still needs reapplication.
How often should I reapply outdoors?
About every two hours, and after swimming or sweating according to the product directions.
Sources and further reading
Sources checked 2026-10-08. This article is general education, not a diagnosis or individual treatment plan. Ask a qualified clinician about persistent symptoms, pregnancy or medication questions.