Brand from United States: Kiehl's. A 3-month intensive serum that mixes powdered retinol with serum just before use.By delivering concentrated retinol powder to the skin at once, it quickly approaches facial changes that tend to appear with age.The serum contains adenosine, which focuses on collagen that supports the skin.It leads to firm skin that bounces back.Please refrain from using it around the eyes.How to use:Open the attached bag and take out the capsule containing the powder.Turn the bottom of the bottle serum up and remove the bottom lid. Keep the removed lid.Fix the capsule inside to the part where the bottom lid is removed so as to close the lid.Push the cap of the capsule into the bottle with your palm.Make sure there is powder in the bottle.Shake the bottle up and down until the powder and liquid are evenly mixed.Remove the capsule, put it back on the original lid, and close it tightly.Use only at night.Please refer to the mixing method above and be sure to mix the bottle serum and powd