Niacin (nicotinic acid)
Once a cholesterol medicine. It changes the numbers, but in large trials it did not prevent heart attacks or strokes, and it caused serious harm. A statin does what niacin was hoped to do.
At a glance
| Our verdict | Improves cholesterol numbers but did not prevent heart attacks, strokes or deaths in large trials, and raised the risk of diabetes, infection, bleeding and liver damage. |
| Sold for | Cholesterol (claimed) |
| How sure the evidence is | High that it does not prevent heart disease |
| Cost a month | About $10 to $25 (estimated) |
Written for adults in Canada. It explains the evidence; it is not advice for you personally. Last reviewed 20 October 2026.
Supplement Check
Is it right for you?
Taking niacin for cholesterol? Large trials found no benefit and real harm. Your check flags it for a consultation and shows what works instead. Our Supplement Check looks at:
- Liver disease
- An active stomach ulcer
- Diabetes (a caution)
- Gout
- Pregnancy
- Every medicine you take
- The total across everything you already take, against the safe upper limits
Coming soon. The Supplement Check and the Online Health Assessment open once our safety testing is complete.
$59 when it opens, paid once. Adults 18 and over, anywhere in Canada. While the service is new, Dr. French reads every report himself, and your report arrives within 3 working days. More about the Supplement Check
What it is
Vitamin B3 in the form of nicotinic acid, used as a cholesterol medicine at 1 to 3 g a day. It comes as immediate-release (“flush”), “no-flush” and slow-release (sustained- or time-release) products. It is not the same as nicotinamide, the other form of B3, which does not cause flushing and does not change cholesterol. Multivitamins contain small amounts: one sport multivitamin gives 30 mg of nicotinic acid and 30 mg of nicotinamide a day.
How it acts
Nicotinic acid switches on a receptor (GPR109A) that releases prostaglandin D2 and causes the flush. It reduces the liver's output of fat-carrying particles, raising high-density lipoprotein (HDL, “good”) cholesterol and lowering triglycerides, low-density lipoprotein (LDL) cholesterol and lipoprotein(a). Better numbers did not mean fewer heart attacks. A breakdown product of excess niacin (4PY) has been linked to heart and blood-vessel events, and caused blood-vessel inflammation in mice: observational and animal work, not proof. [1]
What it is used for, and what the evidence says
| Use | What the trials found | How sure we are |
|---|---|---|
| Heart attack, stroke and death | A Cochrane review of 23 trials and 34,829 people: no fewer deaths, heart attacks or strokes, and twice as many people stopped because of side effects. [2] | High |
| Added to a statin | AIM-HIGH was stopped early because niacin was not helping. [3] HPS2-THRIVE (25,673 people): no fewer vascular events, and more serious harm: new diabetes and loss of blood-sugar control, infections, bleeding and muscle problems. [4] | High |
| Liver damage by form (harm) | 12 of 23 people (52%) on slow-release niacin developed liver toxicity, against none on immediate-release. [5] | One small randomised trial |
| Excess niacin breakdown products | Higher levels of 4PY were linked to about twice the rate of major heart events (1.89 and 1.99 times in two groups of people), and 4PY caused blood-vessel inflammation in mice. [1] | Low (observational and animal) |
| “Detox” and energy | No trial in our review. The flush is a blood-vessel reaction to prostaglandin, not a sign of anything being cleared. | No evidence |
How sure we are: High means further research is very unlikely to change the answer; Moderate, it might; Low, it may well change; Very low, we are very unsure. These follow the GRADE method that guideline panels use.
Benefits
- Death, heart attack, stroke: No reduction; High
- Added to a statin: No fewer events; more serious harm; High
- Cholesterol numbers (HDL up; LDL, triglycerides down): Changed, without fewer events; High
Risks and side effects
- Flushing: redness, warmth and itching.
- Liver damage, worst with slow-release forms (52% in one trial). [5]
- New diabetes and higher blood sugar, infections, bleeding and muscle problems. [4]
- Raised uric acid and gout.
- Twice as many people stopped it because of side effects. [2]
Interactions with medicines
Niacin has no effect of note on the liver enzymes (cytochrome P450) that clear medicines. Its interactions add to the medicines' effects or side effects.
| Medicine | What can happen | What to do |
|---|---|---|
| Statins | Muscle damage | Do not take; discuss with your doctor |
| Insulin and other diabetes medicines | Blood sugar control is lost | Do not take; discuss with your doctor |
| Blood pressure medicines | Low blood pressure during the flush | Discuss with your doctor |
| Multivitamins and other products with nicotinic acid | Adds to the total | Counted against the 35 mg upper limit |
Who should not take it
- Liver disease.
- An active stomach ulcer.
- Diabetes (a caution).
- Gout.
- Pregnancy: not for cholesterol.
- Prescribed niacin: do not stop it suddenly without the doctor who prescribed it; book a consultation.
- Under 18: outside the Supplement Check.
Dose and timing
We do not recommend a dose. For reference, trials for cholesterol used nicotinic acid 1 to 3 g a day. Health Canada's upper limit is 35 mg a day of synthetic niacin from supplements and fortified food (set for flushing), [6] and its multivitamin rules allow at most 500 mg, with a flushing warning from 10 mg of nicotinic acid. [7] Nicotinamide is counted separately: it does not flush.
If your doctor continues it: liver tests, blood sugar or average blood sugar (HbA1c), and uric acid.
What we know about Canadians
Pellagra, the disease of niacin deficiency, is essentially absent in Canada because flour is fortified. We found no Canadian survey of nicotinic-acid supplement use. Our population review lists anyone taking high-dose niacin, along with people stacking several products and older women, among those most likely to go over an upper limit; no Canadian survey has measured how many do. Even one standard multivitamin can come close: that multivitamin's 30 mg of nicotinic acid is 86% of the 35 mg limit.
How sure are we: very low. No Canadian data on niacin use or intake above the limit; deficiency statement from fortification, not a measured survey.
An honest comparison: heart attack and stroke prevention
Cost a month in Canadian dollars, estimated.
| Option | Effect | How sure we are | Cost a month (CAD) |
|---|---|---|---|
| Niacin (nicotinic acid) | No fewer events; more serious harm [2, 4] | High | $10 to $25 |
| Mediterranean-style diet, soluble fibre | Not compared in numbers in this review | Not graded | — |
| Statin (for example rosuvastatin) | 22% fewer major vascular events for each 1 mmol/L lower LDL cholesterol [8] | High | $10 to $15 |
Read honestly: niacin costs about the same as a statin, and in large trials it did not prevent heart attacks or strokes, while the statin does.
Why we don't recommend it
We do not sell niacin (nicotinic acid) and our check never recommends it. In large trials it did not prevent heart attacks, strokes or deaths, and it caused diabetes, infections, bleeding and liver damage.
Already taking it for cholesterol? Book a consultation before you continue. If a doctor prescribed it, do not stop it suddenly without them. Nicotinamide is a different form of B3 and this advice does not apply to it.
Niacin improves cholesterol numbers, which is why it was used. But two large outcome trials and a Cochrane review of almost 35,000 people found no fewer heart attacks, strokes or deaths, and more serious harm, worst with slow-release forms. A generic statin costs about the same and prevents events. So our current advice is not to sell niacin, and to flag anyone taking it for cholesterol for a consultation.
Supplement Check
Before you buy it, get it checked
Taking niacin for cholesterol? Large trials found no benefit and real harm. Your check flags it for a consultation and shows what works instead. Our Supplement Check looks at:
- Liver disease
- An active stomach ulcer
- Diabetes (a caution)
- Gout
- Pregnancy
- Every medicine you take
- The total across everything you already take, against the safe upper limits
Coming soon. The Supplement Check and the Online Health Assessment open once our safety testing is complete.
$59 when it opens, paid once. Adults 18 and over, anywhere in Canada. While the service is new, Dr. French reads every report himself, and your report arrives within 3 working days. More about the Supplement Check
Disclosure of financial interest
White Pine Medical earns money from products bought through our Fullscript dispensary. Dr. French's Code of Ethics requires him to tell you this. You do not have to buy anything from us: every product is named by its ingredient and dose so you can buy it at any pharmacy, and the advice is the same wherever you buy it, or if you buy nothing.
References
- Ferrell M, Wang Z, Anderson JT, Li XS, Witkowski M, DiDonato JA, et al. A terminal metabolite of niacin promotes vascular inflammation and contributes to cardiovascular disease risk. Nat Med. 2024;30(2):424-434.
- Schandelmaier S, Briel M, Saccilotto R, Olu KK, Arpagaus A, Hemkens LG, et al. Niacin for primary and secondary prevention of cardiovascular events. Cochrane Database Syst Rev. 2017;6(6):CD009744.
- AIM-HIGH Investigators, Boden WE, Probstfield JL, Anderson T, Chaitman BR, Desvignes-Nickens P, et al. Niacin in patients with low HDL cholesterol levels receiving intensive statin therapy. N Engl J Med. 2011;365(24):2255-67.
- HPS2-THRIVE Collaborative Group, Landray MJ, Haynes R, Hopewell JC, Parish S, Aung T, et al. Effects of extended-release niacin with laropiprant in high-risk patients. N Engl J Med. 2014;371(3):203-12.
- McKenney JM, Proctor JD, Harris S, Chinchili VM. A comparison of the efficacy and toxic effects of sustained- vs immediate-release niacin in hypercholesterolemic patients. JAMA. 1994;271(9):672-7.
- Health Canada. Dietary reference intakes tables: reference values for vitamins [Internet]. Ottawa: Health Canada; [read 20 Oct 2026]. Available from: https://www.canada.ca/en/health-canada/services/food-nutrition/healthy-eating/dietary-reference-intakes/tables/reference-values-vitamins.html.
- Health Canada. Multi-Vitamin/Mineral Supplements monograph, version dated 26 Jun 2026 (risk statement added 24 Apr 2026). https://webprod.hc-sc.gc.ca/nhpid-bdipsn/atReq?atid=multi_vitmin_suppl&lang=eng
- Cholesterol Treatment Trialists' (CTT) Collaboration, Baigent C, Blackwell L, Emberson J, Holland LE, Reith C, et al. Efficacy and safety of more intensive lowering of LDL cholesterol: a meta-analysis of data from 170,000 participants in 26 randomised trials. Lancet. 2010;376(9753):1670-81.
Costs marked as estimates are typical Canadian retail or pharmacy prices, before any drug plan. Certainty grades are ours unless the review gave its own.