Niacin (vitamin B3, as nicotinic acid) was one of the first lipid-lowering drugs, and its story is a useful lesson in the gap between changing a lab number and changing outcomes.
Quick answer: At prescription-level doses, niacin raises HDL and lowers triglycerides and LDL. But large trials of adding niacin to statin therapy found no reduction in heart attacks or strokes and more side effects, so it is now used far less. It can also raise blood sugar and uric acid and affect the liver. This is a prescriber-level decision, not a supplement-aisle one.
What it does to lab numbers
Nicotinic acid in gram-range doses lowers triglycerides by a sizable amount, lowers LDL modestly, and raises HDL. This is why it was popular. The over-the-counter niacin in a multivitamin is a small fraction of these amounts and does not do the same thing. In AIM-HIGH, median HDL rose 25% with niacin compared with 12% with placebo, and LDL fell 14% compared with 7.6%.
What outcome trials found
Two large trials added extended-release niacin to statin treatment in people with heart disease or high cardiovascular risk. In both, the lab numbers changed but cardiovascular events did not fall, and the second trial found more serious adverse effects. Guidelines no longer recommend routine addition of niacin to statins.
| Detail | AIM-HIGH | HPS2-THRIVE |
|---|---|---|
| Participants | 3,414 adults with vascular disease and low HDL, all on simvastatin | 25,673 adults at cardiovascular risk, all on simvastatin (with or without ezetimibe) |
| Treatment | Extended-release niacin 1,500 to 2,000 mg/day vs placebo (with small niacin dose to maintain blinding) | Extended-release niacin/laropiprant 2 g/40 mg vs placebo |
| Follow-up | About 32 months; stopped early | About 4 years |
| Primary outcome | 16.4% vs 16.2% (p = 0.80): no benefit | 13.2% vs 13.7% (p = 0.29): did not meet the primary endpoint |
| Lab changes | HDL +25% vs +12%; LDL -14% vs -7.6% (median, baseline to 3 years) | Not reported in the summary cited here |
| Notable safety findings | Ischemic stroke 1.6% vs 0.9% (small numerical excess) | New-onset diabetes 9.1% vs 7.3%; diabetic complications 11.1% vs 7.5%; bleeding 2.5% vs 1.9%; infections 8.0% vs 6.6%; GI problems 4.8% vs 3.8% |
Sources for the table: the ACC summary of AIM-HIGH and the ACC press release on HPS2-THRIVE. In AIM-HIGH, the trial was stopped about 18 months early because it became evident that adding extended-release niacin would not be beneficial.
The lesson: a better number is not the same as a better outcome
The HDL idea was appealing. People with low HDL had more heart disease, so raising HDL seemed like a way to reduce it. Niacin raised HDL, and the heart events did not fall.
| Measure | Niacin group | Placebo group | What it shows |
|---|---|---|---|
| HDL change | +25% | +12% | The lab number moved more with niacin |
| LDL change | -14% | -7.6% | Also moved more with niacin |
| Primary cardiovascular endpoint | 16.4% | 16.2% | Events did not fall |
The absolute differences in the table are small in the wrong direction for a treatment: 16.4% versus 16.2% is a 0.2 percentage-point gap in favor of placebo, well within chance (p = 0.80). HPS2-THRIVE, a much larger trial, reported 13.2% versus 13.7%, a 0.5 point difference that was not statistically significant (p = 0.29). Neither shows a benefit that would justify the side effects. This is why you should be skeptical when any supplement is marketed for “raising HDL” or “lowering triglycerides” without outcome evidence: the lab number is only a stand-in for what you actually care about.
Flushing and the “no-flush” myth
Niacin causes flushing, itching, and warmth from prostaglandin release. Taking it with food and aspirin (if your clinician agrees) can reduce this. “No-flush” inositol hexanicotinate products do not release enough free nicotinic acid to change lipids in studies, so avoid them if you want a lipid effect. Flushing is also a useful clue about a product: if a bottle labeled niacin does not flush at all, it may be a form that does not do what high-dose nicotinic acid does.
Risks that matter for metabolic health
| Risk | Why it matters | Who should be especially careful |
|---|---|---|
| Higher blood sugar | Niacin can raise glucose; HPS2-THRIVE reported more new-onset diabetes (9.1% vs 7.3%) | Prediabetes, diabetes, insulin resistance |
| Higher uric acid | Can trigger gout | History of gout |
| Liver effects | Enzyme elevations and, uncommonly, serious injury, especially with sustained-release forms | Liver disease, alcohol use, other liver-affecting medicines |
| Muscle problems with statins | Interaction question with statins | Anyone on a statin |
| Flushing and itching | Prostaglandin-mediated warmth and redness | Anyone starting niacin |
- Raises blood sugar, which is a real concern in prediabetes, diabetes, and insulin resistance.
- Raises uric acid, which can trigger gout.
- Liver effects: enzyme elevations and, uncommonly, serious injury, especially with sustained-release forms.
- Interactions: risk of muscle problems with statins; see supplements and statins.
In HPS2-THRIVE, new-onset diabetes occurred in 9.1% of the niacin/laropiprant group and 7.3% of the placebo group, a difference of 1.8 percentage points, or about 1.25 times as many. Diabetic complications were 11.1% versus 7.5%. Bleeding was 2.5% versus 1.9%, and infections 8.0% versus 6.6%. These are the kinds of findings that moved niacin from a routine add-on to a niche medicine.
Blood sugar note: If you take insulin, sulfonylureas, or other glucose-lowering medicine, niacin can change your glucose control in either direction as doses are adjusted. Symptoms of low blood sugar include shakiness, sweating, confusion, and a fast heartbeat. Do not start high-dose niacin without your prescriber. See supplements and metformin for the general principle of checking supplements against diabetes medicines.
Who niacin might still be discussed for
Niacin has not disappeared from medicine. Prescribers may still consider it in specific circumstances, for example when other options are unsuitable, and the decision rests on a person’s lipid pattern, medicines, and risks. That is a decision made with monitoring of glucose, uric acid, and liver tests, not an over-the-counter experiment. If a clinician raises niacin, ask what outcome they hope to improve, how it will be monitored, and what the alternatives are.
Forms of vitamin B3: why the label matters
“Niacin” and “vitamin B3” cover several chemical forms. Nicotinic acid is the form that flushes and the form studied for lipids. Niacinamide, also called nicotinamide, is a different form that does not cause flushing and is not the one used for lipid treatment. Inositol hexanicotinate is the so-called “no-flush” form discussed above. A label that says only “B3” or “niacin complex” without naming the form cannot be matched to the research, and that is a reason to ask the manufacturer or choose a different product. If you want to read a label with confidence, our guide to reading a supplement label covers what to look for.
How to evaluate a supplement that promises to fix HDL or triglycerides
The niacin story is a template for evaluating any lipid claim. Ask four questions. First, which number does the product claim to change, and is that the same as the outcome you care about? Second, was it tested in a large trial with real outcomes, or only for lab changes? Third, what were the side effects, and did the trial look for them in the right people? Fourth, was the product in the trial the same as the product you can buy? For niacin, the honest answers are that it changes lab numbers, the outcome trials were disappointing, the side effects included more diabetes and bleeding, and the trial products were prescription formulations used under supervision. Those answers are the reason this page treats niacin as a topic for a prescriber, and they are the same questions to ask of every other supplement in our cholesterol and triglyceride guides.
Where it fits
See supplements for high triglycerides and supplements for cholesterol for the comparison, and the complete guide to high triglycerides and what low HDL means for the numbers. The hub is supplements for metabolic syndrome. Better-characterized options for LDL include beta-glucan, and the other supplements in the group include bergamot and red yeast rice, which carries its own statin-type risks.
Common mistakes
- Chasing HDL. Raising HDL with niacin did not reduce events in the large trials.
- Using multivitamin niacin as a lipid treatment. The amounts are far lower than the gram-range doses studied.
- Choosing a “no-flush” product for a lipid effect. Studies do not support it.
- Adding niacin to a statin on your own. Muscle and liver questions apply.
- Ignoring blood sugar. Niacin can raise glucose.
- Starting without baseline labs. Glucose, uric acid, and liver tests are part of the picture.
Questions to bring to your appointment
- Do my lipid numbers justify any medicine or supplement beyond lifestyle changes?
- How would niacin affect my blood sugar and uric acid?
- Are there better-studied options for my triglycerides or HDL?
- If we try it, what labs do we check before and after?
Frequently asked questions
Does niacin raise HDL?
At prescription-level doses, yes. In AIM-HIGH, median HDL rose 25% with extended-release niacin versus 12% with placebo. But raising HDL did not reduce heart attacks or strokes in the large trials.
Does niacin lower the risk of heart attack?
Two large trials that added extended-release niacin to statin therapy, AIM-HIGH and HPS2-THRIVE, did not find a significant reduction in major cardiovascular events, and the second reported more serious adverse effects.
Is the niacin in my multivitamin enough to affect cholesterol?
No. The amounts in a multivitamin are a small fraction of the gram-range doses studied for lipids.
Do “no-flush” niacin products work for cholesterol?
Inositol hexanicotinate products do not release enough free nicotinic acid to change lipids in studies, so they are not a way to get the lipid effect without flushing.
Can niacin raise blood sugar?
Yes. It can, and HPS2-THRIVE reported more new-onset diabetes with niacin/laropiprant (9.1% vs 7.3%). People with prediabetes, diabetes, or insulin resistance should discuss it with a prescriber.
Can I take niacin with a statin?
That is a prescriber decision. The large trials of adding niacin to statins did not show a benefit, and combining them can raise muscle-problem risk. Do not combine them on your own.
About the author: Charles Kirkland is the founder of Metabolic Clarity Labs and author of The Journey Back. He is not a physician. This is general education, not a medically reviewed treatment plan.
Sources checked October 31, 2026. Discuss personal decisions with a qualified clinician or pharmacist. Do not start, stop, or change prescribed treatment based on this article.
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