Supplement analysis backed by scientific evidence · PT

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Limited evidenceHeart & metabolic

Vitamin B3 (Niacin)

Niacin reliably raises HDL and lowers triglycerides, but two large outcome trials showed no reduction in cardiovascular events on top of statins — and real harm, including new-onset diabetes, infections and bleeding. The lipid numbers move; the patients do not benefit.

What the science says

  • Improves lipid numbers (raises HDL, lowers triglycerides and Lp(a)) Strong evidence

    Extended-release niacin at 1.5-2 g/day raises HDL-C by roughly 20-25%, lowers triglycerides by 20-30% and reduces Lp(a) by around 20%. This is consistent across dozens of trials — it is the single best-documented biochemical effect of any B vitamin.

  • Reduces cardiovascular events Limited evidence

    AIM-HIGH randomised 3,414 patients with atherosclerotic disease and low HDL on simvastatin to extended-release niacin 1.5-2 g/day and was stopped early for futility despite the expected HDL rise. HPS2-THRIVE randomised 25,673 patients to niacin plus laropiprant and found no reduction in major vascular events plus a significant excess of serious adverse events. Two large trials, both negative — this claim is effectively refuted for statin-treated patients.

  • Causes clinically meaningful harm at pharmacologic doses Strong evidence

    HPS2-THRIVE found significant excesses of new-onset diabetes, disturbances of diabetes control, serious infection and serious bleeding with niacin/laropiprant. Combined with flushing and hepatotoxicity risk, this harm profile is the main reason niacin has fallen out of guideline use.

  • Treats pellagra and niacin deficiency Strong evidence

    Niacin cures pellagra (dermatitis, diarrhoea, dementia), which is why it was discovered in the first place. Deficiency is rare in fortified-grain countries but occurs in alcohol use disorder, carcinoid syndrome, Hartnup disease and isoniazid therapy. Ordinary nutritional doses of 15-20 mg/day suffice.

Dosage & safety

Studied doseRDA is 16 mg NE/day for men and 14 mg NE/day for women — trivially met by diet. Lipid trials used 1,500-2,000 mg/day of extended-release nicotinic acid, titrated up over weeks. Nicotinamide (niacinamide) does not raise HDL and does not cause flushing; 500 mg twice daily has separate dermatology evidence for reducing non-melanoma skin cancer. Inositol hexanicotinate ('no-flush niacin') releases little free nicotinic acid and does not meaningfully alter lipids.
SafetyProstaglandin-mediated flushing (burning, itching, redness) affects most users at gram doses and is the main reason for discontinuation; taking with food or pretreating with aspirin blunts it. Dose-dependent hepatotoxicity — sustained-release formulations carry the highest risk and fulminant hepatic failure has been reported. Raises fasting glucose and precipitates new-onset diabetes; worsens glycaemic control in existing diabetes. Increases uric acid and can trigger gout. Increased serious infection and bleeding in HPS2-THRIVE. Interacts with statins (myopathy risk) and antihypertensives (additive hypotension). Prescription niacin products exist in many countries; gram-level use should be physician-supervised, and it is no longer recommended as add-on therapy to statins.

Scientific references

Where to buy

Life Extension, Vitamin B3 Niacin, 500 mg, 100 Capsules

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