Niacin (B3)
Nicotinic acid / nicotinamide / vitamin B3 · Metabolic
Moves lipid numbers convincingly and failed to move outcomes, the clearest surrogate-endpoint lesson in this catalog.
What it is
Vitamin B3, and one of the sharpest examples in this catalog of why "vitamin" does not mean "harmless". At nutritional amounts it prevents deficiency; at the gram-level amounts sold for cholesterol it is effectively a drug, one whose major outcome trials failed and which carries real liver risk in the wrong form.
How it works
Niacin becomes NAD, needed by hundreds of enzymes, that is the vitamin role, and deficiency (pellagra) is dramatic and rare. The cholesterol effect is entirely separate pharmacology at doses 50-100x the vitamin requirement: it suppresses fat release from adipose tissue, lowering triglycerides and LDL while raising HDL. Impressive on paper, which is exactly what made the trial failures so instructive.
Which form to buy
The form in the cholesterol literature. Causes intense flushing, harmless but genuinely unpleasant.
The trial-matched form, flush and all.
Less flushing; hepatotoxic and requiring monitoring, though its liver record is substantially better than OTC SUSTAINED-release products, which carry the highest risk.
Prescription territory, not a self-directed choice.
The formulation associated with the greatest hepatotoxicity risk.
The riskiest way to buy niacin.
Releases little free nicotinic acid, so it neither flushes nor lowers lipids. Sold precisely because it does nothing.
The clearest example of a supplement that works by not working.
No flushing, no lipid effect; has its own genuine dermatology evidence including skin-cancer prevention research.
A different compound for different jobs.
What it actually does, graded
The uncontested vitamin role. Rare in fortified-food countries.
Gram-level nicotinic acid reliably raises HDL and lowers triglycerides and LDL, the numbers genuinely move.
AIM-HIGH found no incremental benefit added to intensive statins, and HPS2-THRIVE (which tested ER niacin PLUS laropiprant) was null with more serious adverse events. Historically, the pre-statin Coronary Drug Project DID show fewer recurrent heart attacks and lower 15-year mortality, niacin worked before statins existed, not alongside them.
A different form entirely. ONTRAC: 386 immunocompetent Australians with 2+ prior non-melanoma skin cancers, 500 mg twice daily, 23% fewer new keratinocyte cancers, with no benefit after stopping, no melanoma finding, and NCI calling general-population evidence inadequate.
Pros and cons
- A genuine vitamin with a genuine deficiency disease behind it
- The lipid effects are real and were once standard therapy
- Cheap
- Adding it to modern statin therapy produced no outcome benefit, which is why guidelines moved away
- Liver toxicity is a real risk at high amounts, greatest with OTC sustained-release products
- Flushing is intense enough that many people quit
- It can worsen blood-sugar control and raise uric acid
What to expect
- Flushing within 15-30 minutes of immediate-release nicotinic acid, hot, red, prickly, and harmless.
- Lipid changes over weeks at pharmacological amounts, under medical supervision.
- At ordinary vitamin amounts: nothing, correctly.
Interactions
Is it for you?
- Diagnosed deficiency, or a lipid strategy your clinician is actively directing
- You are self-treating cholesterol with gram-level niacin, that is drug-dose territory where the outcome trials failed
- You bought "no-flush" niacin expecting lipid effects, it does not produce them
Who should avoid it
- Anyone with liver disease, gout, or poorly controlled diabetes, at high amounts
- Anyone taking gram-level amounts without medical supervision
Research on this supplement
Papers about this supplement, not proof of the claims above. A title says what was studied, which is sometimes a negative result or a different question entirely.
- Meta-analysis of the effect of nicotinic acid alone or in combination on cardiovascular events and atherosclerosis
- Daily Vinegar Ingestion Improves Depression and Enhances Niacin Metabolism in Overweight Adults: A Randomized Controlled Trial
What the evidence says
Pharmacological niacin raises HDL and lowers triglycerides substantially, the numbers look excellent. Then AIM-HIGH and HMSTC/HPS2-THRIVE tested whether that translated into fewer cardiovascular events on top of statins, and it did not; HPS2-THRIVE found excess serious adverse events. Nicotinamide is a separate form used in dermatology that does not cause flushing or move lipids.
What studies used
Requirements sit near 14-16 mg/day; the lipid trials used gram-scale prescription doses. Published studies had not established a preferred timing.
Reported from published studies and product labelling — a record of what was used in research, not a recommendation. What is right for you is a conversation with a clinician.
Watch out for
- The flush is harmless but intense; sustained-release forms marketed to avoid it carry greater hepatotoxicity risk
- Gram-scale niacin can raise blood glucose, uric acid and liver enzymes, this is prescription territory, not a supplement decision
Evidence base
established literature
Large human evidence base: several phase 3 or 4 trial reports, plus multiple meta-analyses or systematic reviews.
This letter measures how much human research exists, not whether it works for you — the tier above (Moderate) is the read on quality.
Research (12)
- Dyslipidaemia in nephrotic syndrome: mechanisms and treatmentNat Rev Nephrol · 2018
- Comparative effects of vitamin and mineral supplements in the management of type 2 diabetes in primary care: A systematic review and network meta-analysis of randomized controlled trialsPharmacol Res · 2023
- Extended-release niacin (nicotinic acid)/laropiprantDrugs · 2009
- Mechanism of action of niacinAm J Cardiol · 2008
- Hyperlipidaemia and cardiovascular disease: low HDL-cholesterol as a therapeutic target in statin-treated patients: a role for nicotinic acid (niacin)?Curr Opin Lipidol · 2010
- Niacin and laropiprantDrugs Today (Barc) · 2010
- [Niacin in therapy]Postepy Hig Med Dosw (Online) · 2007
- Cholesterol efflux potential and antiinflammatory properties of high-density lipoprotein after treatment with niacin or anacetrapibArterioscler Thromb Vasc Biol · 2010
- Meta-analysis of the effect of nicotinic acid alone or in combination on cardiovascular events and atherosclerosisAtherosclerosis · 2010
- Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary diseaseN Engl J Med · 2001
- Advancing therapy for hypercholesterolemiaExpert Opin Pharmacother · 2010
- Fibrates and niacin: is there a place for them in clinical practice?Expert Opin Pharmacother · 2014
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