Retinol Precautions
1. From low to high concentration Retinol should be applied 1 nights per week to start. If the skin isn’t irritated by it, After 2 week, move up to 2 nights a week. After 4 week, move up to 3 nights a week. After 6 week, move up to 4 nights a week. After 9 week, change to use every day. After 11 week, start with a retinol 0.5. If you have sensitive or dry skin, it is recommended that you use a lower strength retinol product and start with only using it a few days per week. Slowly, you can build up to using it every night. 2. Use Retinol Only at Night and Wear SPF Every Day "Retinol makes...