“I cannot talk fully yet on the product's effectiveness as retinol takes 3-6 months before benefits are observed. But I am rating this a 5 already as it is gentle enough for beginners like me. I have dry acne-prone skin, and so far, my skincare which now involves gentle cleansers, sunscreens, moisturizer with niacinamide, once-a-week BHA exfoliant and once a week of this serum is working well. I started a once-a-week routine and sandwiched it between two moisturizer applications at night. I only used a pea-sized amount of this serum and lots of sunscreen during the day. I keep my bottle in the fridge to keep it away from light and heat.”