Glycolic acid usage frequency depends on the product's strength, your skin type, and tolerance. For beginners, it is recommended to start using glycolic acid 1-2 times per week to allow your skin to build tolerance without irritation. As your skin adapts, you can increase usage to 2-3 times a week, which is generally considered optimal for most people to see benefits like smoother, brighter skin. Some people with tougher, more accustomed skin may use it daily, but this should be approached cautiously and preferably under guidance. It is best to use glycolic acid at night since it increases your skin's sensitivity to the sun, requiring diligent sunscreen use during the day. Avoid combining glycolic acid with other potent exfoliants or retinoids simultaneously to minimize irritation. Always follow up with moisturizer to prevent dryness and protect your skin barrier. If you have sensitive skin, start with lower concentrations (around 1-5%) and observe how your skin reacts, reducing frequency if you notice redness, dryness, or irritation. Regular and consistent use with proper sun protection can maximize glycolic acid’s skin-renewing benefits safely.