Niacin (Nicotinic Acid, Vitamin B3)
Pronunciation: (NYE-uh-sin).
- Generic name
- Niacin (nicotinic acid, Vitamin B3)
- Brand names
- Endur-acin, Nicotinic Acid, Nicotex, Niacin, Nicotin, Niacor
- Drug class
- Cardio-Metabolic
Availability and supply rules vary by country
Trade names by country: United States
Australia: · Full directory
What Niacin (nicotinic acid, Vitamin B3) is and how it works
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how Niacin (nicotinic acid, Vitamin B3) works
Niacin (nicotinic acid) inhibits hepatic synthesis of very-low-density lipoprotein (VLDL), leading to decreased LDL cholesterol and triglycerides. It also reduces the breakdown of HDL, increasing HDL cholesterol. The exact mechanism for lipid modification is not fully understood but involves inhibition of lipolysis in adipose tissue and decreased hepatic esterification of triglycerides. (1) (2) (3)
What Niacin (nicotinic acid, Vitamin B3) is used for
Dyslipidemia (specifically hypertriglyceridemia and low HDL cholesterol)
Dyslipidemia (specifically hypertriglyceridemia and low HDL cholesterol) (2) (3)
Pellagra (niacin deficiency)
Cardiovascular disease prevention (in certain patient populations)
Cardiovascular disease prevention (in certain patient populations) (2) (3)
Before taking Niacin (nicotinic acid, Vitamin B3)
Do not take / not appropriate for
- Contraindicated in active liver disease, unexplained persistent elevations of liver enzymes, active peptic ulcer disease, and hypersensitivity to niacin. (Contraindication) (2)
Tell your clinician about
(2) (3)How to take Niacin (nicotinic acid, Vitamin B3)
- General Instructions: Take niacin exactly as prescribed by your healthcare provider. Do not increase your dose or frequency without medical advice.. Adult Dosing: For cholesterol management: Start with 250 mg once daily at bedtime, gradually increasing as tolerated to a typical maintenance dose of 1-2 g/day in divided doses. Maximum dose is usually 6 g/day. For deficiency: 50-100 mg 3 times daily.. Pediatric Dosing: For deficiency: 5-20 mg daily, depending on age and clinical need. Use in children for cholesterol management is rare and should be under specialist supervision.. Administration: Take with food to reduce stomach upset. Extended-release forms should be swallowed whole, not crushed or chewed.. When To Stop: Seek medical attention promptly if you develop severe side effects, signs of liver problems, or allergic reactions, and let the clinician you see advise on whether to continue or stop the medicine.. Storage: Store at room temperature, away from moisture and heat. Keep out of reach of children.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (2) (3)
Missed dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose—do not double up.
Overdose
Symptoms of overdose may include severe flushing, nausea, vomiting, diarrhea, abdominal pain, dizziness, and liver toxicity. Seek emergency medical attention or contact a poison control center immediately. (2) (3)
Side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Flushing
Incidence: Reported in the clinician-authored database; frequency not established
Itching
Incidence: Reported in the clinician-authored database; frequency not established
Nausea
Incidence: Reported in the clinician-authored database; frequency not established
Vomiting
Incidence: Reported in the clinician-authored database; frequency not established
Diarrhea
Incidence: Reported in the clinician-authored database; frequency not established
Increased blood sugar
Incidence: Reported in the clinician-authored database; frequency not established
Liver problems
Incidence: Reported in the clinician-authored database; frequency not established
Serious warnings
May cause severe liver toxicity, especially at high doses — serious
Symptoms: May cause severe liver toxicity, especially at high doses. Can worsen peptic ulcers or cause gastrointestinal bleeding. May increase blood sugar levels—monitor in diabetes. Can cause significant flushing; pre-medication with aspirin may help. Use with caution in patients with gout or kidney disease.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2) (3)
Contraindications recorded in the clinician database — serious
Symptoms: Contraindications recorded in the clinician database: Contraindicated in active liver disease, unexplained persistent elevations of liver enzymes, active peptic ulcer disease, and hypersensitivity to niacin. Use with caution in patients with a history of liver disease, diabetes, gout, renal impairment, or gallbladder disease. Monitor for hepatotoxicity, hyperglycemia, and hyperuricemia.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2) (3)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Recorded interactions | Niacin can interact with statins (increasing risk of muscle toxicity), antihypertensive drugs (increased risk of hypotension), anticoagulants (increased bleeding risk), and diabetes medications (may affect blood sugar control). Always inform your healthcare provider of all medications and supplements you are taking. | (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
Requires a primary-source research pass before this section can be completed. (2) (3)
Breastfeeding
Requires a primary-source research pass before this section can be completed. (2) (3)
Children
Frequency: Not recommended for pediatric use. Weight Based: Not established for pediatric use. Max Daily Dose: Not recommended for pediatric use. Max Single Dose: Not recommended for pediatric use. Age Restrictions: Safety not established in children (2) (3)
Renal_impairment
Requires a primary-source research pass before this section can be completed. (2) (3)
Hepatic_impairment
Requires a primary-source research pass before this section can be completed. (2) (3)
Monitoring
(2) (3)Storage
Requires a primary-source research pass before this section can be completed.
Professional information
Clinician-facing context only. This section does not replace current product labeling.
General
Indication: Dyslipidemia (specifically hypertriglyceridemia and low HDL cholesterol)
Dose summary: Two distinct FDA-labeled dosing regimens exist depending on formulation. Extended-release niacin (Niaspan): initiate at 500 mg once daily at bedtime; increase by no more than 500 mg per 4-week period; maintenance range 1000-2000 mg once daily at bedtime; doses above 2000 mg/day are not recommended. Immediate-release niacin (Niacor): start with 250 mg (one-half tablet) as a single daily dose after the evening meal; frequency and total daily dose may be increased every 4-7 days as tolerated, usually to 1.5-2 g/day; if lipid control is inadequate after 2 months, dose may be increased up to 3 g/day in divided doses; maximum is generally 6 g/day.
Renal context: Extended-release niacin (Niaspan) FDA label: use in patients with renal impairment has not been formally studied; NIASPAN should be used with caution in patients with renal impairment. Immediate-release niacin (Niacor) FDA label contains no specific renal dose-adjustment guidance; it directs general monitoring rather than a numeric adjustment. Renal function and dose tolerance should be assessed by the prescriber in either case. (2) (3)
Hepatic guidance
Both FDA labels reviewed for this page treat hepatic status as a gating safety issue rather than a dose-adjustment table. Extended-release niacin (Niaspan) is contraindicated in active liver disease or significant/unexplained hepatic dysfunction, including unexplained persistent transaminase elevations. Immediate-release niacin (Niacor) has no numeric hepatic dose adjustment, but its label directs closer observation and liver-function monitoring in patients with a past history of jaundice or hepatobiliary disease, and periodic liver function testing during treatment in general.
Frequently asked questions
What is niacin used for?
Niacin is used to treat and prevent vitamin B3 deficiency (pellagra) and to manage cholesterol levels in certain patients, helping to lower LDL cholesterol and triglycerides and raise HDL cholesterol.
What are the most common side effects of niacin?
The most common side effect is flushing (redness and warmth of the face/neck). Other common effects include mild headache, upset stomach, and nausea.
How can I reduce flushing caused by niacin?
Taking niacin with food and avoiding hot beverages or alcohol around the time of dosing can help. Your doctor may recommend taking aspirin 30 minutes before niacin to reduce flushing.
Is niacin safe during pregnancy or breastfeeding?
Niacin is generally considered safe at recommended dietary doses during pregnancy and breastfeeding, but high doses for cholesterol management should only be used if clearly needed and prescribed by a doctor.
Can niacin interact with other medications?
Yes, niacin can interact with statins, antihypertensives, anticoagulants, and diabetes medications. Always inform your healthcare provider about all medicines you take.
How long does it take for niacin to work on cholesterol?
Improvements in cholesterol levels may be seen within a few weeks, but maximum benefit may take several months. Regular monitoring is important.
Do I need regular blood tests while taking niacin?
Yes, your doctor will monitor your liver function, cholesterol levels, and blood sugar regularly while you are on niacin therapy.
What happens if I take too much Niacin (Vitamin B3)?
Taking too much Niacin can lead to symptoms such as severe flushing, itching, gastrointestinal upset, and liver damage. In extreme cases, it may cause hypotension or arrhythmias. If you suspect an overdose, seek immediate emergency medical attention. Do not attempt to self-treat an overdose.
Can I drink alcohol while taking Niacin (Vitamin B3)?
It is generally advised to limit or avoid alcohol consumption while taking Niacin. Both Niacin and alcohol can cause flushing and may increase the risk of liver damage. Combining them can exacerbate these effects and potentially lead to more severe side effects. Always consult your healthcare provider for personalized advice.
Is Niacin (Vitamin B3) safe during pregnancy?
Niacin's safety during pregnancy is categorized as 'Consult doctor.' While some Niacin is essential, high doses can be harmful. It is crucial to consult your healthcare provider before taking Niacin if you are pregnant, planning to become pregnant, or breastfeeding. They can assess the risks and benefits for your specific situation.
What is the mechanism of action of Niacin (nicotinic acid, Vitamin B3)?
Niacin (nicotinic acid) inhibits hepatic synthesis of very-low-density lipoprotein (VLDL), leading to decreased LDL cholesterol and triglycerides. It also reduces the breakdown of HDL, increasing HDL cholesterol. The exact mechanism for lipid modification is not fully understood but involves inhibition of lipolysis in adipose tissue and decreased hepatic esterification of triglycerides. (1) (2) (3)
What is the generic name of Niacin (Nicotinic Acid, Vitamin B3)?
The generic name is Niacin (nicotinic acid, Vitamin B3). It is sold under brand names including Endur-acin, Nicotinic Acid, Nicotex, Niacin, Nicotin, Niacor.
What class of drug is Niacin (nicotinic acid, Vitamin B3)?
Niacin (Nicotinic Acid, Vitamin B3) is classed as: Cardio-Metabolic.
References
- Niacin (Vitamin B3) Medicine RecordMedGuideGlobal · Global · accessed 2026-08-07 · source 1
- NIASPAN (niacin) extended-release tablet, prescribing informationU.S. Food and Drug Administration (DailyMed) · United States · accessed 2026-08-07 · source 2
- NIACOR (niacin) immediate-release tablet, prescribing informationU.S. Food and Drug Administration (DailyMed) · United States · accessed 2026-08-07 · source 3
- NICOMIDE (NIACINAMIDE, ZINC GLYCINATE, LEVOMEFOLATE CALCIUM, CUPRIC OXIDE, SELENIUM AND CHROMIUM) TABLET [AVION PHARMACEUTICALS, LLC] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 4
- Niacin — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 5
- Niacin — RxNorm normalized drug concept (RXCUI 7393)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 6
Brand names by country
Single-ingredient Niacin (nicotinic acid, Vitamin B3) names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Niacor500 mg · avondale pharmaceuticals, llc