Nicotinamide vs Niacinamide vs Niacin: Which Is Which for Skin

Vitamin B3 comes in several forms. Nicotinamide and niacinamide are identical: same molecule, two names. "Niacinamide" is the name usually used in skincare, "nicotinamide" in medical studies.

Niacin, also called nicotinic acid, is a different form. Your body can turn both into the same active coenzymes, but at high doses they act very differently: niacin causes flushing and affects cholesterol, nicotinamide does neither.

Niacin (nicotinic acid) at doses well above the daily requirement causes the well-known "niacin flush": warmth, redness, itching and tingling of the face and upper body, usually within half an hour. It is uncomfortable but usually harmless.

High-dose niacin was used as a prescription cholesterol treatment. At those doses, especially in slow-release forms, it can cause liver damage, raise blood sugar and trigger gout. It was not the form used in the skin cancer trials and should not be swapped in for nicotinamide.

Nicotinamide does not cause flushing and does not change cholesterol. This is the form that was used in the ONTRAC trial (The New England Journal of Medicine, 2015), where 500 mg twice daily was linked to about 23% fewer new non-melanoma skin cancers over a year in people who had already had at least two.

At the studied dose it was well tolerated. At much higher doses (several grams a day), liver problems have been reported, and people with kidney disease clear it more slowly. That is why a doctor should be involved before taking it at study doses.

Topical niacinamide, usually at 2-5% (sometimes higher) in serums and moisturizers, is popular for redness, oiliness, uneven tone and the skin barrier. There is reasonable evidence for some of these cosmetic uses, and it is generally well tolerated on the skin.

It is not the same as the oral treatment studied for skin cancer. No trial has shown that a niacinamide cream lowers skin cancer risk, and a serum does not replace sunscreen.

Daily requirement: adults need about 14-16 mg of niacin equivalents a day, which most people get from food (meat, fish, grains, legumes). A typical multivitamin contains around that amount.

Skin cancer trials: 500 mg of nicotinamide twice a day, 1,000 mg in total, which is roughly 60 times the daily requirement. This is a medical dose, not a vitamin top-up.

Cholesterol treatment (niacin): historically 1-2 grams a day or more, only under medical supervision. This is a different drug use and a different form.

Look for the words "nicotinamide" or "niacinamide" in the supplement facts, and check the amount per capsule and per serving. If the label just says "niacin" or "nicotinic acid", it is the flushing form.

Be careful with "no-flush niacin". It is usually inositol hexanicotinate, which is neither nicotinamide nor the form studied for skin, and evidence on how much B3 it actually delivers is weak. B-complex and multivitamin products contain much smaller amounts of B3 than the trials used.

If you have had several non-melanoma skin cancers, nicotinamide is a reasonable question to raise with your dermatologist. Niacin is not a substitute, and a niacinamide serum is not the same thing. If you have never had skin cancer, there is no trial evidence that any form of B3 lowers your risk.

Whatever you decide, talk to your doctor first, especially if you have kidney or liver disease, have had a transplant, are pregnant or breastfeeding, or take regular medicines. Sunscreen, shade and regular skin checks stay the foundation.