In general, the use of sunscreen is always recommended; not only to prevent sunburn, but also because sun exposure can cause skin damage and premature aging. We especially recommend sun protection for products that stimulate cell renewal (e.g. products with the active ingredients BHA or Retinol) or have a brightening effect (e.g. products like the Brightening Booster or the Spot and Discoloration Treatment). You can always find information about when sun protection is important on the pages of our products. We recommend that you use a sunscreen with an SPF of at least 30 for optimal protection.