Break the vial with the appropriate cylinder and insert the dosing cup. Apply the content of 1 vial in the evening, spreading the product drop by drop on a well cleansed face and neck (avoid the eye area). Do not use in combination with other retinoid-based treatments. Gradual application is recommended, by limiting initial use to once or twice a week, gradually increasing the frequency up to daily evening application. Do not expose yourself to the sun, we recommended to use a high-protection sunscreen the next morning during periods of product use. In case of irritation, stop the treatment. Do not use during pregnancy and breastfeeding.