Niacinamide and retinol can be combined in one product, which may be easier and more convenient. But they're also available as separate products. If you're using these ingredients in separate products, it's recommended to apply niacinamide first and to then follow with retinol.
Using niacinamide before retinol works well. So does combining them into one product. A 2016 study found that a product containing retinol, niacinamide, hexylresorcinol, and resveratrol improved fine lines, sallowness, wrinkling, hyperpigmentation, and skin tone.
Niacinamide and retinol can be used together with a five-minute gap between application but are likely to be just as effective if you use them at separate times of the day.
Don't Mix: Retinol with vitamin C, benzoyl peroxide, and AHA/BHA acids. AHA and BHA acids are exfoliating, which can dry out skin and cause further irritation if your skincare routine already includes retinol. As for benzoyl peroxide and retinol, they cancel each other out.
Norwalk, CT, dermatologist Deanne Mraz Robinson, MD, stresses these ingredients are great when they hit your skin solo, but a definite no-no when applied together. “A mixture of retinoids/retinols with alphahydroxy acids, like glycol, can lead to extreme irritation and redness.”
Layering products correctly is important if you want your products to work. If you place one product on your skin, like a serum, and follow up with another product whose molecules are smaller than the first, like a toner, then the second product cannot penetrate the first layer.
Retinol is best applied at night, since it can increase your skin's sensitivity to the sun. When you do go outside, be sure to use sunscreen to protect your face. Also, keep in mind that you don't need to use retinol on a daily basis for it to be effective at treating acne. Two to three times per week may be enough.
Strength and Timeframe
In general, retinoids are stronger than retinol. They contain a higher concentration of the product, and the molecular structure of vitamin A in this form allows it to turn over skin cells at a faster rate than retinol.
Hyaluronic Acid and Niacinamide
These water-based treatments are a great pair and are made for all skin types — especially babes with dry, acne-prone skin. You'll find niacinamide, a form of vitamin B3, in my Rewind Retinol Serum. Use hyaluronic acid first, followed by my retinol for the best results.
The Niacinamide Powder should never be used with a product that has a non-water-based formula or a pH below 5 or above 7. Especially, it should never be combined with a vitamin C or direct acid (such as AHAs, BHAs, and PHAs).
People use niacinamide to prevent vitamin B3 deficiency and related conditions such as pellagra. It is also used for acne, diabetes, cancer, osteoarthritis, aging skin, skin discoloration, and many other conditions, but there is no good scientific evidence to support most of these uses.