RESEARCH MONOGRAPH · KDC-MN-197

Niacin (Nicotinic Acid)

May 9, 2026 Kodiac biolabs Research Revised May 30, 2026 2 min read

Our opinion on this compound

80/100

Genuinely effective for lipids, genuinely useless as an NAD precursor at supplement doses

Nicotinic acid is one of those compounds where you have to be careful about which question you're asking, because it has two completely different pharmacological identities depending on the dose. At low doses it's vitamin B3, an NAD precursor that's been understood since the pellagra work of the 1920s and 30s. At high doses (1-3 grams) it's a lipid-modifying drug with a real but increasingly obsolete role in clinical lipidology. The pharmacology at those two ranges is essentially unrelated.

The high-dose lipid story: niacin remains the best LDL/Lp(a) modifier we have outside of PCSK9 inhibitors, raises HDL meaningfully, and lowers triglycerides. The AIM-HIGH and HPS2-THRIVE trials, however, failed to show cardiovascular outcome benefit when added to statins, which has largely killed clinical use despite the lipid panel effects being real. Mechanism is HCAR2 (GPR109A) agonism in adipocytes (the niacin flush mechanism) plus direct effects on hepatic apoB secretion.

The vitamin-dose story: nicotinic acid does raise NAD+ in tissues, but only to the same extent as nicotinamide does, and modern interest has shifted decisively to nicotinamide riboside and nicotinamide mononucleotide because the kinetics and tissue distribution are different. Nicotinic acid as a NAD booster has been mostly superseded by NR and NMN in the longevity-research space, partly because of the flush issue and partly because of pharmacokinetics.

What's interesting and underappreciated: HCAR2 (GPR109A) is genuinely a useful pharmacological target outside lipids. The receptor is expressed on adipocytes, immune cells, and intestinal epithelium, and signal there mediates the anti-inflammatory effects of beta-hydroxybutyrate and short-chain fatty acids. Niacin is the cleanest tool compound we have for studying HCAR2 in vivo. That's probably its most useful current research application.

Sourcing is trivial, this is a commodity B vitamin and USP-grade material is cheap. The flush is the classic dose-limiting effect: cutaneous prostaglandin D2 release, peaks 20-30 minutes after ingestion, fully tachyphylactic with chronic dosing. Slow-release formulations have hepatotoxicity risk that immediate-release doesnt. For research use the immediate-release crystalline material is what you want.

Underrated as a tool compound for HCAR2 work, otherwise eclipsed by newer NAD precursors. Worth knowing the dose-dependent identity split before designing any experiment.

Evidence: 88
Mechanism: 88
Reliability: 80
Safety: 70
Sourcing: 92
Value: 88
Signal: 65
Staying power: 70

Plain-language summary Intrigue 55 / 100

Niacin (nicotinic acid) is vitamin B3 in its acid form, distinct from nicotinamide. It causes flushing (a vasodilatory side effect) at therapeutic doses. Used historically for high cholesterol and as a NAD+ precursor. Not stocked by Kodiac. This monograph is provided for research and educational reference.

Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

Vitamin B3 / NAD+ precursor

Vitamin B3 used at high doses for dyslipidemia and at low doses as an essential nutrient and NAD+ precursor.

Abstract

Niacin (nicotinic acid; CAS 59-67-6; molecular formula C6H5NO2; molecular weight 123.11) is vitamin B3, used at low doses (10 to 30 mg) as an essential nutrient and NAD+ precursor, and at high doses (1 to 3 grams) for dyslipidemia management. The high-dose niacin lipid effect (LDL reduction, HDL elevation, triglyceride reduction) is mediated through hepatic VLDL synthesis effects. The flushing response (cutaneous vasodilation, warmth, itching) at high doses is a prostaglandin-mediated effect that can be mitigated by aspirin pre-treatment or by use of immediate-release formulations with gradual titration. Niacinamide (nicotinamide) does not produce flushing but lacks the lipid effects.

Mechanism of action

NAD+ precursor (essential nutrient role). High-dose lipid effects through hepatic VLDL synthesis modulation.

Reported research dose ranges

Reported research dose ranges in the literature.

References

Carlson LA. Nicotinic acid: the broad-spectrum lipid drug. J Intern Med 2005.

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KDC-MN-197

The full reference document is provided strictly for research use only. It reports research dose ranges from the published literature, not instructions for use in humans or animals.

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FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

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Niacin (Nicotinic Acid)

Abstract

Mechanism of action

Reported research dose ranges

References

Read the full monograph

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Abstract

Mechanism of action

Reported research dose ranges

References

Read the full monograph

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