You should generally reapply sunscreen every two hours to maintain effective protection from UV rays
. However, if you are swimming, sweating, or towel drying, you need to reapply more frequently-potentially every 40 to 80 minutes-to ensure the sunscreen remains effective
. Even if you use a high SPF sunscreen, reapplication every two hours is necessary because no sunscreen provides continuous protection for eight hours
. If you are indoors away from windows, reapplication may not be needed as often, possibly every 4 to 6 hours, since UV exposure is lower in that environment
. But if you spend time near windows or go outside intermittently, you should follow the two-hour rule from the time of sun exposure
. In summary:
- Reapply every 2 hours during regular outdoor activity.
- Reapply every 40 to 80 minutes if swimming, sweating, or towel drying.
- Reapply less frequently (every 4-6 hours) if indoors away from windows.
- Use enough sunscreen (about one ounce for the body) and cover all exposed areas thoroughly
This routine helps prevent sunburn, skin damage, and reduces the risk of skin cancer.
