Stability & the pH Sweet Spot
The good news is that niacinamide is one of the most stable vitamins in use. The main thing to look for when evaluating a niacinamide serum is the pH of the formulation. The pH range should be between 4 to 6 — and the reason is that outside this range, niacinamide can much more easily convert into niacin, which is irritating to the skin.
Look for niacinamide products formulated in a pH range of 4 to 6. The sweet spot appears to be around 5 to 5.5, where the rate of niacinamide breakdown is at its lowest.
Why Niacinamide Is a Skincare Superstar
Niacinamide is used in a huge variety of skincare products — and for good reason. It's one of the most researched and proven ingredients available. Here's what it brings to your routine:
Another huge advantage of niacinamide is that it's usually well tolerated even by those of us with very sensitive skin. For a much deeper look at how all of this works, check out our comprehensive guide:
Click here for Maelove's Deep Guide to Niacinamide →
Niacin: The Evil Cousin
If you've experienced irritation from a niacinamide product in the past, it might be that you used a product that was not well formulated — and that led to niacinamide converting into niacin. Niacin is a known skin irritant that causes skin flushing: redness often accompanied by an itching and burning sensation. This can occur as a response to topical niacin or large doses of oral niacin.
Those with schizophrenia are often missing this niacin flush response (Messamore et al. 2003) — an interesting observation that has been used as a diagnostic marker in research.
Those who are more science-savvy might ask: isn't niacin also a form of Vitamin B3? You're correct. If you take it orally, both niacin and niacinamide are forms of Vitamin B3 that your body can use. However, as a topical, niacin doesn't cross the stratum corneum while niacinamide does. And more importantly, though niacinamide is well tolerated by even those with the most sensitive skin, niacin is a known irritant that causes flushing in most people.
When you put niacinamide in a skincare product whose pH is not properly calibrated, you're much more likely to end up with unwanted niacin. Always check that a niacinamide product is formulated within the pH 4–6 range.
The Science Behind Hydrolysis
Here is a study from Finholt and Higuchi entitled "Rate studies on the hydrolysis of niacinamide" — hydrolysis basically means breaking down. For example, "hydrolyzed collagen" means broken-up collagen. In the same way, niacinamide hydrolyzes into niacin.
If you look at the chart from Finholt and Higuchi's research, the lowest point of the rate of niacinamide hydrolysis falls between pH 4 to 6 — with 5 to 5.5 appearing to be the sweet spot. This is precisely where we formulated our NIA 10 Calming Serum.
- Feldmann RJ and Maibach HI (1970). "Absorption of Some Organic Compounds Through the Skin in Man." J Invest Dermatol 54(5): 399–404.
- Finholt P, Higuchi T (1962). "Rate Studies on the Hydrolysis of Niacinamide." J Pharm Sci 51(7): 655–661.
- Franz TJ (1975). "Percutaneous Absorption on the Relevance of In Vitro Data." J Invest Dermatol 64(3): 190–195.
- Messamore E, Hoffman WF, Janowsky A (2003). "The niacin skin flush abnormality in schizophrenia: a quantitative dose-response study." Schizophr Res 62(3): 251–258.
