The Ordinary recommends performing a patch test prior to incorporating a new product into your skin care routine.

Mix a quarter scoop of the spoon provided with a water-based treatment in the palm of your hand and apply to the face in the morning and or evening. Avoid contact with eyes, if contact occurs rinse thoroughly with water. Wash hands after handling. Do not mix with formulations with a pH of 5 or lower.

Mixing Guide: In its truest form, Niacinamide is readily water-soluble and dissolves in water-based products, such as serums and creams, with ease. The Ordinary's 100 Niacinamide Powder can be mixed into any non-conflicting, water-based treatment, provided that the pH of the base is between 5.1 and 7.0. When it comes to the choice of a water-based base to mix with this formula, there are several options available within The Ordinary brand.

These include the following:

• Hyaluronic Acid 2 B5
• Natural Moisturizing Factors HA
• ''Buffet'' Copper Peptides 1
• Matrixyl 10 HA
• Argireline Solution 10

Given the powder format of the product, one may wonder how much Niacinamide is in the resulting mixture. From a theoretical standpoint, if 1 4 scoop of the powder consists approximately of 0.05g Niacinamide, then when mixed with 4 drops of the selected base, the resulting mixture is estimated to yield a 10-15 concentration of Niacinamide.

Note: The Ordinary does not recommend combining Niacinamide with topical Vitamin C (L-Ascorbic Acid, Ethylated L-Ascorbic Acid and Vitamin C derivatives) in the same regimen. If Vitamin C is used as part of your skincare regimen, The Ordinary advises to apply them at alternate times with this formula (ideally Vitamin C in the PM and this formula in the AM). In addition, The Ordinary does not recommend dissolving Niacinamide Powder in Direct Acids.

Precautions: If irritation occurs, rinse off, cease use, and consult a physician. Use only as directed on unbroken skin. Patch testing prior to use is advised. Refer to this website for a patch test guide, regimen guide, and product compatibility. Keep out of reach of children.