How many drops of niacinamide should I use?

Use 2-3 drops of niacinamide serum.

According to instructions, you should:

1. Use the dropper provided with the serum.
2. Dispense a few drops (specifically 2-3 drops) onto your fingertips.
3. Apply the serum evenly to your face and neck.
4. Gently dab it in.
5. Follow up with a niacinamide gel moisturizer and a niacinamide hybrid sunscreen for best results.