Niacin
Also known as: Vitamin B3, Nicotinic acid, Niacinamide, Nicotinamide
Effective Dosage
No established dose from provided studies for general supplementation
What the Science Says
Niacin is an essential B vitamin (vitamin B3) that your body needs to convert food into energy and build NAD+, a molecule critical for hundreds of metabolic reactions. Clinical research shows it can modulate the immune system — in one trial of glioblastoma patients, niacin increased circulating memory T cells and natural killer cells while shifting the immune environment toward an anti-tumor profile. It is also the definitive treatment for pellagra, a deficiency disease causing skin, gut, and neurological symptoms, with a systematic review of over 1,200 cases showing full symptom resolution within about 27 days of supplementation.
What It Doesn't Do
Won't improve male fertility or pregnancy rates — a large RCT found an antioxidant blend containing niacin actually trended toward lower pregnancy rates. Not proven to treat cancer on its own. No evidence from these studies that it builds muscle, burns fat, or boosts athletic performance. The antimicrobial effects seen in lab meat-preservation studies don't translate to taking a supplement to fight infections in your body.
Evidence-Based Benefits
Niacin is essential for converting food into energy and plays a critical role in DNA repair and the production of stress and sex hormones in the adrenal glands. It has been shown to improve cholesterol levels, particularly by lowering LDL cholesterol and triglycerides while raising HDL cholesterol.
Strong EvidenceEffective at: 14-35 mg daily
Source: auto-research
Absorption & Bioavailability
Generally considered good when taken orally; no specific bioavailability data reported in the provided studies
Red Flags to Watch For
- High-dose niacin causes cutaneous flushing (skin redness, burning, itching) — a well-documented side effect linked to its GPR109A receptor activity
- An antioxidant supplement containing niacin was associated with a significantly lower ongoing pregnancy rate (15.5% vs 21.5%) in a large RCT — do not assume it is universally beneficial
- Niacin is used as a placebo control in some psilocybin trials, meaning researchers consider it pharmacologically inert for depression — don't expect mood benefits
- Drug interactions exist: isoniazid (a TB drug) is a leading cause of drug-induced pellagra by blocking niacin metabolism — check with a doctor if on medications
- Pellagra risk is highest in food-insecure populations and those with malabsorption disorders; supplementing without addressing the root cause is insufficient
Products Containing Niacin
See how Niacin is used in these analyzed products:
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-04-06