Niacin (vitamin B3)

Best for

Raise cellular NAD+ levels

Large effect, needs confirmation · 1000–1500 mg/day for 4–48 weeks · 7 studies , n=184

46 papers · 4 claims · 94 outcomes scored · 4 positive

Outcomes

What niacin (vitamin b3) actually does, by outcome

Each row is one outcome with effect size, evidence base, the dose that worked in trials, and time to first effect. Magnitude tiers come from native-unit MCID where available, Cohen's d otherwise.

Outcome Effect size Evidence Dose Weeks Rank

Raise cellular NAD+ levels Large effect, needs confirmation

Replenish the coenzyme that powers hundreds of metabolic reactions.

7 RCTs n=184 1000–1500 mg 4–48 wk #2/2

29599478·32320006·35235774·35620522 +3 more

large

7 RCTs n=184

1000–1500 mg

4–48 wk

#2 /2

Raise good cholesterol levels Likely benefit

Boosts the cholesterol that pulls fat out of artery walls.

17 meta-analyses n=199k 500–3000 mg 6–166 wk #2/71

17583186·20216298·21565796·22892157 +13 more

moderate

17 meta-analyses n=199k Meta-analyzed I²=92%

500–3000 mg

6–166 wk

#2 /71

Lower bad and total cholesterol Proven benefit

Cuts the cholesterol that builds into artery plaque over time.

12 meta-analyses n=163k 500–3000 mg 8–166 wk #3/103

23444397·23872591·24035168·25750540 +8 more

moderate

12 meta-analyses n=163k Meta-analyzed I²=100%

500–3000 mg

8–166 wk

#3 /103

Lower triglycerides Likely modest benefit

Reduces the blood fats that rise after meals and drive heart risk.

11 meta-analyses n=158k 500–2000 mg 8–166 wk #2/89

22840917·22892157·23444397·23872591 +7 more

small

11 meta-analyses n=158k Meta-analyzed I²=80%

500–2000 mg

8–166 wk

#2 /89

Outcome	Effect	Evidence	Dose	Weeks	Rank
Raise cellular NAD+ levels Large effect, needs confirmation	large	7 RCTs n=184	1000–1500 mg	4–48 wk	#2/2
Raise good cholesterol levels Likely benefit	moderate	17 meta-analyses n=199k Meta-analyzed	500–3000 mg	6–166 wk	#2/71
Lower bad and total cholesterol Proven benefit	moderate	12 meta-analyses n=163k Meta-analyzed	500–3000 mg	8–166 wk	#3/103
Lower triglycerides Likely modest benefit	small	11 meta-analyses n=158k Meta-analyzed	500–2000 mg	8–166 wk	#2/89

Buy well

Recommended Niacin (vitamin B3) products

Real products that dose Niacin (vitamin B3) where the research does, in a clean formulation, from brands we've audited. We only list ones we'd stand behind.

Chosen for adequate Niacin (vitamin B3) dosing vs. the studied range, a clean formulation (grade A–C), and independent brand-quality audits. Not sponsored.

Risk profile

Adverse events and known drug interactions

Safety events

hepatitis / hepatic toxicity severe

Revascularization (CABG, PCI, carotid endarterectomy) severe

Stroke severe

vasovagal syncope severe

hepatic encephalopathy severe

severe coagulopathy severe

hemodynamic instability / hypotension severe

Flushing moderate

Drug interactions

Isoniazid major decreases concentration

Cisplatin major decreases effect

Oxaliplatin major decreases effect

Antineoplastic Agents major decreases effect

Warfarin major increases toxicity

Indomethacin moderate decreases effect

MK-0524 moderate decreases effect

Laropiprant (DP1 Antagonist) moderate decreases effect

other moderate decreases effect

Laropiprant (PGD2 Receptor Antagonist) moderate decreases effect

Co-studied with

Supplements that share evidence with niacin (vitamin b3)

Drug:Simvastatin 21 shared outcomes · d=0.47
Drug:Ezetimibe 3 shared outcomes · d=0.10

Sources

Generated August 14, 2026

Niacin (vitamin B3)

What niacin (vitamin b3) actually does, by outcome

Recommended Niacin (vitamin B3) products

Adverse events and known drug interactions

Supplements that share evidence with niacin (vitamin b3)

More evidence for Niacin (vitamin B3)

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