Niacin (B3)
Niacin (vitamin B3) is the raw material for NAD+ and NADP+, the cofactors that energy metabolism in every cell runs on. At a normal dietary status, there is no evidence that extra niacin raises energy levels or fat burning.
What the research shows
No sound research in humans.
Two independent reviews of B vitamins in athletes, Woolf and Manore (2006) and Peeling (2023), reach the same conclusion: extra intake improves performance only in people whose nutritional status is poor or marginal. In people with a normal status, no measurable gain in strength, endurance or perceived energy has been found. Correcting a deficiency is therefore a different question from the energy claim on a pre-workout label, and only the first one is supported. The Minto (2017) meta-analysis covers the tolerable upper intake level and says nothing about performance. The Yang (2016) review describes the role of niacin in NAD metabolism, which explains the mechanism without testing the claim.
Who it makes sense for: Worth taking if your intake is genuinely too low, for example on a very restricted diet, with alcohol use, or with a condition that impairs absorption. For anyone eating normally, the 15 to 35 mg in a pre-workout does nothing for performance. The warm, tingling skin that many people read as proof it works is the familiar nicotinic acid flush, and it says nothing about energy or strength.
How we weigh evidenceClinical dosage
Origin
Natural & syntheticNiacin (vitamin B3) is naturally found in chicken, tuna, turkey, peanuts, mushrooms, and avocado. Your body can also produce it from the amino acid tryptophan. In supplements as nicotinic acid (causes flushing) or nicotinamide (no flushing).
Safety
The US upper limit for supplements is 35 mg per day, to prevent flushing. In Europe that limit for nicotinic acid is 10 mg per day, considerably lower. A meta-analysis across 47 studies and nearly 12,000 people calls the 35 mg limit fairly conservative. Above that limit flushing can occur: warmth and reddening of the skin.
For comparison
100g of chicken breast contains about 13mg of niacin, almost your entire daily need. The niacin flush in pre-workouts feels like you're blushing rapidly across your whole body. It's comparable to the warm feeling after a hot shower, but from the inside.
Dosage by weight and gender
The recommended daily niacin intake is 16mg for men and 14mg for women (IOM). Pre-workouts sometimes use higher doses (20-50mg nicotinic acid) for the flush effect. Body weight doesn't play a significant role. The upper limit is 35mg per day as supplement. Pregnant women need 18mg per day.
Frequently asked questions
What does niacin do in pre-workout?
Niacin (vitamin B3) plays a role in energy metabolism. In pre-workouts, nicotinic acid is sometimes added for the 'flush', a warm, tingling sensation from vasodilation. This doesn't directly improve performance but provides a sensory effect. Nicotinamide doesn't cause flushing.
Is niacin dangerous?
Niacin is an essential vitamin and safe at normal doses. The niacin flush (redness, warmth) is harmless and fades after 30-60 minutes. At very high doses (>500mg nicotinic acid per day) liver issues may occur. Pre-workout doses are well below this threshold.
Why does my skin tingle after pre-workout?
That can have two causes: beta-alanine or niacin. Beta-alanine causes tingling (paresthesia) mainly in the face and hands. Niacin (nicotinic acid) causes a warm, red flush across your whole body. Both are harmless and temporary.
Scientific sources
The clinical dosages on this page are based on peer-reviewed research.
- NAD(+) metabolism: Bioenergetics, signaling and manipulation for therapyYang Y et al. (2016)Funded by: Amerikaanse NIH (NIDDK en NIGMS).
- Definition of a tolerable upper intake level of niacin: a systematic review and meta-analysis of the dose-dependent effects of nicotinamide and nicotinic acid supplementationMinto C et al. (2017)
- B-vitamins and exercise: does exercise alter requirements?Woolf K et al. (2006)
- Considerations for the Consumption of Vitamin and Mineral Supplements in Athlete PopulationsPeeling P et al. (2023)Funded by: Auteurs verklaren geen belangenverstrengeling.
Pre-workouts with Niacin (B3)
BSN N.O.-Xplode
3 flavors
Legendary pre-workout from BSN with 6g citrulline, 3g creatine, and 200mg caffeine. Popular for years with a complete formula for energy and pump.
5% Nutrition 5150
2 flavors
Hardcore pre-workout with 400mg caffeine from multiple sources, 4g citrulline, and 2.5g beta-alanine. Not for beginners — one of the strongest pre-workouts on the market.
Cellucor C4 Ripped
2 flavors
C4 variant for the cutting phase with L-Carnitine and CLA. Less caffeine (150mg), no creatine — focused on fat burning.
Cellucor C4 Ultimate
Premium C4 with 300mg caffeine, 6g citrulline malate, 3.2g beta-alanine, and 3g creatine. Fully clinically dosed — top of the C4 line.
We keep the dosages and values on this page as accurate as possible based on selected studies. New research may change these values. Nothing on this page is medical advice. If you have any doubts, always consult a doctor.