How often should I use this mask, and are the lifting and smoothing effects permanent?

This is a single-use booster mask, not a daily treatment. Most people get good results using it once or twice a week — for example, before an event, after travel, or whenever the skin looks dull and tired. The hydrolysed collagen forms a light moisture-holding film that temporarily improves the look of firmness and smoothness by reducing the feeling of dryness; the strawberry extract contributes a brighter, more refreshed appearance. These effects are cosmetic and last several hours to a day, not permanently. They work best when the mask is part of a balanced routine: daily cleansing, a suitable moisturiser, and sun protection. Overusing sheet masks (daily or multiple days in a row) can overwhelm the barrier, especially with fragranced formulas, and does not increase the benefit. Store unopened sachets in a cool, dry place away from direct sunlight; the serum can degrade faster if kept warm. Once opened, use immediately — do not reseal. This product is not a substitute for targeted treatments (retinoids, acids, prescription care) but can complement them on off-days when you want a low-effort hydration and clarity boost.