For first use, press firmly with both thumbs on the packaging lid until the cartridge is fully engaged to release the vitamin C. Unscrew the white cap and check that all of the vitamin C powder has been released. Screw on the dropper and shake the product for 10 seconds to blend in the vitamin C. Apply 5 drops to the cleansed face and neck.
Every evening; as a 1- to 3-month treatment course