Amplify the effect of your creams with a serum. This is a dermatologically tested product, which means that it's been tested on humans.
From Sephora
First Aid Beauty Facial Radiance Niacinamide Dark Spot Serum 29.5Ml
Asos
First Aid Beauty Facial Radiance Niacinamide Dark Spot Serum 30ml-No colour
This product is also available at 1 unverified store.