Niacin (Nicotinic Acid)
Also known as: nicotinic acid, vitamin B3, pyridine-3-carboxylic acid, flushing niacin, immediate-release niacin
Nicotinic acid is the acid form of vitamin B3 and, with nicotinamide, one of the two standard niacin sources in supplements. Both are almost completely absorbed and converted to the NAD coenzymes that run hundreds of redox reactions. Nicotinic acid is distinctive for causing a harmless but unpleasant skin flush at 30 to 50 mg or more, and for lipid effects that only appear at gram-level drug doses. Supplement formulas keep it at nutritional levels, while multi-hundred-milligram lipid regimens are prescription territory with liver and glucose monitoring.
Research summary
Precursor to NAD+ and NADP+, coenzymes for energy metabolism and redox reactions; also activates the GPR109A receptor, which drives prostaglandin-mediated flushing.
Dosage
Daily amounts, of compound.
| Lowest studied | Typical range | Highest studied | Upper limit |
|---|---|---|---|
| 14 mg | 16–35 mg | 35 mg | 35 mg |
NIH ODS — UL is 35 mg/day of supplemental niacin (both nicotinic acid and nicotinamide) for adults 19+, based on flushing; does not apply under medical supervision
RDA is 16 mg NE for men and 14 mg NE for women; DV 16 mg NE (1 mg niacin = 1 NE). NIH ODS reports flushing from 30 to 50 mg or more, reduced by taking with food, dose ramping, or extended-release forms. dose_max_studied is capped at the UL for validation; ODS describes drug-level use of 1,000 to 3,000 mg/day for lipids, with hepatotoxicity risk (higher for extended-release), glucose intolerance, hypotension, and eye effects, so those amounts belong to medical use. Some niacin-only supplements contain 500 mg or more per serving, well above the UL.
Standardization: ≥99% nicotinic acid (USP)
Source material: synthetic
Forms of Niacin (Vitamin B3)
| Form | Typical dose | Element % | Formats | Price |
|---|---|---|---|---|
| Niacin (Nicotinic Acid) | 16–35 mg | — | Capsule, Tablet, Powder, Liquid | low |
| Niacinamide (Nicotinamide) | 16–35 mg | — | Capsule, Tablet, Powder, Gummy, Liquid | low |
Format suitability
- Capsule
- Powder
- Tablet
- Softgel
- Gummy
- Liquid
Flushing makes it unsuitable for chewables and gummies at meaningful doses; nicotinamide is used there instead.
Formulation notes
High doses can raise blood glucose and interact with antidiabetes drugs and statins; hepatotoxicity with sustained high doses. Include a flush warning on any product above about 30 mg.
- Has an upper limit
- Notable drug interactions
Sources
Related ingredients
Vitamin B12 (Cyanocobalamin)
VitaminCyanocobalamin is the synthetic, highly stable form of vitamin B12 used in most supplements and fortified foods.
Typical: 100–1,000 mcg
Vitamin B12 (Methylcobalamin)
VitaminMethylcobalamin is one of the two coenzyme forms of vitamin B12 that the body uses directly, in this case for the methionine synthase reaction that recycles homocysteine and supports methylation.
Typical: 100–1,000 mcg
Thiamin HCl (Vitamin B1)
VitaminThiamin hydrochloride is one of the two standard water-soluble salts of vitamin B1 used in supplements (the other is the mononitrate).
Typical: 1.5–100 mg
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Fatty acidFish oil concentrate is a refined marine oil enriched in the long-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Typical: 500–2,000 mg
CoQ10 (Ubiquinone)
AntioxidantCoenzyme Q10 in its oxidized form, ubiquinone, is the standard, most-studied CoQ10 ingredient.
Typical: 100–300 mg