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.”
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.
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.
Also avoid retinol if you're going to be spending a lot of time in direct sunlight without proper sun protection. Retinol can make your skin more sensitive to the sun, so it's important to use sunscreen with at least SPF 30 every day — even when it looks cloudy.
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).
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.
For prescription retinols, you'll typically apply this step onto dry skin before your moisturizer—but always check with your dermatologist. You may be advised to use it after a moisturizer, which buffers the retinol and lessens risk of irritation.