COSRX - The Retinol 0.5 Oil

Start small and slow! During evening care, apply 1 to 2 drops to hand and tap with fingertips from inside out, let absorb. Limit initial use to three times per week; gradually increase frequency to every other night, use as tolerated. Have an 'adaption period' when using retinol

Week 1-2: Frequency : use only 2-3 times a week at night.
How to Use : After cleansing, at the moisturizer step, apply 1-2 drops to areas of concern. e.g. under eyes, mouth, forehead and neck.

Week 3: Frequency : may apply every other day at night
How to use : After cleansing, at the moisturizer step, may spread over the entire face.

The "building tolerance" phase can be shortened or extended depending on individual differences. Maintain this phase until no discomfort is experienced. Gradually increase frequency and areas of application.