1What the words and numbers mean
| On the label | What it describes |
|---|---|
| SPF 30, SPF 50 | Sun protection factor. A rating about UVB, the rays most linked to sunburn. Higher numbers are a small step up, not a doubling. |
| Broad spectrum | The product is labeled to cover UVA rays as well as UVB. |
| Water resistant (40 or 80 minutes) | How long the label says protection lasts while swimming or sweating, tested under set conditions. It does not mean waterproof. |
| Mineral filters | Ingredients such as zinc oxide or titanium dioxide, which sit on the surface of the skin. |
| Chemical filters | Ingredients that absorb UV light, listed by names such as avobenzone or octocrylene. |
2Why the directions mention reapplying
Most sunscreen directions say to reapply at regular intervals, commonly about every two hours, and after swimming, sweating or towel drying. The reason is practical: sunscreen wears off, rubs off and gets rinsed off. Follow the directions printed on the product you actually have.
Amount matters as well. The SPF on the label is measured using a generous layer, and many people apply less than that.
3Sunscreen is one layer of several
Public health agencies usually describe sun protection as a set of habits, not one product: shade during the middle of the day, clothing that covers, a hat with a brim, sunglasses, and sunscreen on skin that is left uncovered. Our routine guide shows where sunscreen fits in a morning.
4When to ask someone qualified
If you notice a new spot, or a change in an existing one, that is a question for a clinician, not a label. The same goes for any question about your own skin type, medications, or history. This site explains labels; it cannot assess your skin.
General information only. Serumelo is not a medical provider, clinic, pharmacy, or retailer, and this is not medical, professional, or financial advice. Products and labels change. Check the packaging in your hands and ask a qualified professional about your own skin.