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Niacin (Vitamin B-3), Niacinamide

Be aware that the U.S. Food and Drug Administration does not strictly regulate herbs and dietary supplements. There is no guarantee of strength, purity or safety of products containing or claiming to contain niacin. Decisions to use herbs or supplements should be carefully considered. Individuals using prescription drugs should discuss taking herbs or supplements with a pharmacist or health care professional before starting.


Vitamin B-3 is composed of niacin (nicotinic acid) and is a source of niacinamide. Scientists have studied niacin for the following health problems:

High cholesterol
Niacin has been observed to have substantial benefits in lowering high cholesterol levels. It is particularly effective in raising levels of high-density lipoprotein (HDL or "good cholesterol") levels, but it is less effective at lowering low-density lipoprotein (LDL or "bad cholesterol") levels than some other cholesterol-lowering drugs. Niacin is currently used as one of the first-line treatments of high cholesterol either alone or in combination with other cholesterol-lowering drugs. Niacinamide, which is also present in vitamin B-3, does not have the same effects as niacin on cholesterol levels. Some studies show that niacin can raise homocysteine levels, which may increase the risk of cardiovascular disease.
Pellagra (niacin deficiency)
Pellagra is a disease caused by niacin deficiency. Symptoms of pellagra include skin irritation, diarrhea, dementia or depression. The disease may affect chronic abusers of alcohol. However, diabetes, liver disease, pregnancy and some drugs may also cause niacin deficiency. Both niacin and niacinamide are approved by the U.S. Food and Drug Administration for treating niacin deficiency.
Atherosclerosis (clogged arteries), prevention of heart disease
Niacin has been shown to lower cholesterol levels. Lower cholesterol has been associated with slowing the progression of clogged arteries, and unclogged arteries lessen the risk of heart disease. However, niacin has also been shown to increase the levels of homocysteine, a compound in the blood that increases the risk of clogged arteries.

Scientific evidence from studies in humans supports the use of niacin in combination with other drugs to reduce the risk of clogged arteries in people with high cholesterol. However, more research is needed to determine whether niacin can reduce clogged arteries and prevent heart disease and death when it is used alone.
Niacinamide, a chemical in vitamin B-3, has been proposed as a possible therapy to prevent diabetes or delay the need for insulin. Animal studies of niacinamide use in diabetes have suggested that it may increase the time that oral drug treatment is effective and delay the need for insulin injections. Research in humans has shown mixed results with niacinamide, and most studies had flaws in their designs. More research is needed to determine if niacinamide provides any advantages in delaying or preventing the onset of insulin dependence in individuals with diabetes.

The use of niacin for the treatment of dyslipidemia associated with type 2 diabetes has been controversial because of the possibility of worsening glycemic control. However, a recent randomized, controlled, multicenter trial showed that of 148 patients in the study, only four discontinued because of inadequate glucose control. These researchers reported doses of 1,000 to 1,500 milligrams per day (in a controlled-release formulation) to be a treatment option for type 2 diabetics with dyslipidemia. Check with your physician and pharmacist before starting niacin.
Results from one study suggest that niacinamide, a chemical in vitamin B-3, may help to improve flexibility, reduce inflammation and lessen the need for drugs that are commonly used for pain in people with osteoarthritis. The study was small, and more research is needed to determine if niacinamide provides benefits for this condition.
Alzheimer's disease, cognitive decline
Dementia can be caused by severe niacin insufficiency, but it is unknown whether variation in intake of niacin in the usual diet is linked to neurodegenerative decline. One large, prospective study examined whether dietary intake of niacin was associated with incident Alzheimer's disease and cognitive decline. The authors concluded that dietary niacin may protect against Alzheimer's disease and age-related cognitive decline. Further research is needed to confirm these results.

Unproven Uses    

Niacin has been suggested for many other uses, based on tradition or on scientific theories. However, these uses have not been thoroughly studied in humans, and there is limited scientific evidence about safety or effectiveness. Some of these suggested uses are for conditions that are potentially very serious and even life-threatening. You should consult a health care professional before taking niacin for any unproven use.

Age-related macular degeneration
Alcohol dependence
Bell's palsy
Brain disorders
Cancer prevention
Cataract prevention
Chemotherapy side effects
Drug-induced hallucinations
High blood pressure
HIV treatment and prevention
Intermittent claudication
Ischemic injury prevention
Low blood sugar levels
Memory loss
Ménière's syndrome
Menstrual cramps
Migraine headaches
Motion sickness
Multiple sclerosis
Non-ST-segment elevation acute coronary syndromes
Orgasm enhancement
Peripheral vascular disease
Premenstrual syndrome
Raynaud's phenomenon
Ringing in the ears
Skin disorders
Smoking cessation
Tardive dyskinesia
Taste disturbance (diminished/distorted sense of taste)
Thyroid disease
Tumor detection
Vascular spasm

Potential Dangers    


Side Effects

Pregnancy And Breast-Feeding


Interactions with drugs, herbs and other supplements have not necessarily been thoroughly studied. The interactions listed below have been reported in scientific publications. If you are taking prescription drugs, speak with a health care professional or pharmacist before using herbs or dietary supplements.

Interactions With Drugs

Interactions With Herbs And Dietary Supplements

Use of niacin with chromium polynicotinate, sitosterols and grape seed proanthocyanidin may cause greater cholesterol-lowering effects than any of the agents used alone. However, some research suggests that the use of niacin with antioxidants may slightly decrease the cardiovascular benefits of niacin. More studies are needed in this area. Because niacin alters thyroid hormone levels, it should be used carefully with other supplements that affect thyroid hormone levels, such as bladderwrack.

In theory, niacin may increase the risk of bleeding when taken with other products that are also believed to increase the risk of bleeding. Examples include Ginkgo biloba and garlic (Allium sativum). When niacin is used with herbs such as borage, chaparral, valerian or uva ursi, there may be an increased risk of liver toxicity. Niacin has been shown to increase blood sugar levels and may decrease the blood sugar-lowering properties of herbs such as bitter melon. Combining niacin with vitamin A and vitamin E may lower cholesterol levels more than niacin alone.


The doses listed below are based on scientific research, publications or traditional use. Because most herbs and supplements have not been thoroughly studied or monitored, safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients even within the same brand. Combination products often contain small amounts of each ingredient and may not be effective. Appropriate dosing should be discussed with a health care professional before starting therapy; always read the recommendations on a product's label. The dosing for unproven uses should be approached cautiously, because scientific information is limited in these areas.

The recommended daily dietary intake of niacin ranges from 16 to 35 milligrams. Taking niacin supplements with food may reduce the likelihood of stomach upset. Doses are usually started low and increased slowly to minimize flushing, although aspirin or ibuprofen may reduce the flushing adverse effect.

Adults (Aged 18 Or Older)

Children (Younger Than 18): There are not enough scientific data to recommend niacin for use in children, and niacin is not recommended because of potential side effects. Note that there are concerns about the lack of evidence regarding treatment of childhood lipid disorders, including the long-term psychological and metabolic effects. At this time, diet alteration is acceptable first-line treatment, without the use of lipid-lowing drugs, until adulthood is reached.


Vitamin B-3 is composed of niacin (nicotinic acid) and is a source of niacinamide. Niacin and niacinamide have been suggested as treatments for many conditions. There is scientific support for the use of niacin in lowering total cholesterol and low-density lipoprotein (LDL or "bad cholesterol") levels and in raising levels of high-density lipoprotein (HDL or "good cholesterol"). Niacin is also a well-established treatment for pellagra (niacin deficiency). There is some evidence that niacin may provide benefits for clogged arteries and may prevent heart disease. There is not enough scientific evidence to support the use of niacin or niacinamide for any other medical condition.

Niacin may cause many adverse effects, including flushing, headache, dizziness and itching. Niacin may also raise blood sugar levels, alter thyroid hormone levels, increase uric acid levels and cause liver damage. Therefore, niacin should be used carefully in people with diabetes, thyroid disease, gout and liver disease. It should also be avoided in pregnant or breast-feeding women and in children. Niacin may increase the risk of bleeding. Consult a health care professional immediately if you have any side effects.

The information in this monograph was prepared by the professional staff at Natural Standard, based on thorough systematic review of scientific evidence. The material was reviewed by the Faculty of the Harvard Medical School with final editing approved by Natural Standard.


  1. Natural Standard: An organization that produces scientifically based reviews of complementary and alternative medicine (CAM) topics
  2. National Center for Complementary and Alternative Medicine (NCCAM): A division of the U.S. Department of Health & Human Services dedicated to research

Selected Scientific Studies: Niacin

Some of the more recent studies are listed below:

  1. Armstrong EP, Zachry WM 3rd, Malone DC. Cost-effectiveness analysis of simvastatin and lovastatin/extended-release niacin to achieve LDL and HDL goal using NHANES data. J Manag Care Pharm 2004;May-Jun, 10(3):251-258.
  2. Ascaso JF, Fernandez-Cruz A, Gonzalez Santos P, et al. Significance of high density lipoprotein-cholesterol in cardiovascular risk prevention: recommendations of the HDL Forum. Am J Cardiovasc Drugs 2004;4(5):299-314.
  3. Ayyobi AF, Brunzell JD. Lipoprotein distribution in the metabolic syndrome, type 2 diabetes mellitus, and familial combined hyperlipidemia. Am J Cardiol 2003;Aug 18, 92(4A):27J-33J.
  4. Backes JM, Gibson CA. Effect of lipid-lowering drug therapy on small-dense low-density lipoprotein. Ann Pharmacother 2005;Mar, 39(3):523-526. Epub 2005;Jan 25.
  5. Ballantyne CM, Corsini A, Davidson MH, et al. Risk for myopathy with statin therapy in high-risk patients. Arch Intern Med 2003;Mar 10, 163(5):553-564. Comment in: Arch Intern Med 2003;Jul 14, 163(13):1615-1616. Author reply, 1616.
  6. Bays HE, Dujovne CA, McGovern ME, et al. ADvicor Versus Other Cholesterol-modulating Agents Trial Evaluation: comparison of once-daily, niacin extended-release/lovastatin with standard doses of atorvastatin and simvastatin (the ADvicor Versus Other Cholesterol-Modulating Agents Trial Evaluation [ADVOCATE]). Am J Cardiol 2003;Mar 15, 91(6):667-672.
  7. Berra K. Clinical update on the use of niacin for the treatment of dyslipidemia. J Am Acad Nurse Pract 2004;Dec, 16(12):526-534.
  8. Bhatnagar D. Should pediatric patients with hyperlipidemia receive drug therapy? Paediatr Drugs 2002;4(4):223-230. Review.
  9. Bilchick KC, Henrikson CA, Skojec D, et al. Treatment of hyperlipidemia in cardiac transplant recipients. Am Heart J 2004;Aug, 148(2):200-210.
  10. Birjmohun RS, Hutten BA, Kastelein JJ, Stroes ES. Efficacy and safety of high-density lipoprotein cholesterol-increasing compounds: a meta-analysis of randomized controlled trials. J Am Coll Cardiol 2005;Jan 18, 45(2):185-197.
  11. Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med 2001;345(22):1583-1592.
  12. Bucher HC, Griffith LE, Guyatt GH. Systematic review on the risk and benefit of different cholesterol-lowering interventions. Arterioscler Thromb Vasc Biol 1999;19(2):187-195.
  13. Canner PL, Furberg CD, Terrin ML, McGovern ME. Benefits of niacin by glycemic status in patients with healed myocardial infarction (from the Coronary Drug Project). Am J Cardiol 2005;Jan 15, 95(2):254-257.
  14. Capuzzi DM, Morgan JM, Carey CM, et al. Rosuvastatin alone or with extended-release niacin: a new therapeutic option for patients with combined hyperlipidemia. Prev Cardiol 2004;Fall, 7(4):176-181.
  15. Capuzzi DM, Morgan JM, Weiss RJ, et al. Beneficial effects of rosuvastatin alone and in combination with extended-release niacin in patients with a combined hyperlipidemia and low high-density lipoprotein cholesterol levels. Am J Cardiol 2003;Jun 1, 91(11):1304-1310.
  16. Cheung MC, Zhao XQ, Chait A, et al. Antioxidant supplements block the response of HDL to simvastatin-niacin therapy in patients with coronary artery disease and low HDL. Arterioscler Thromb Vasc Biol 2001;21(8):1320-1326.
  17. Elam MB, Hunninghake DB, Davis KB, et al. Effect of niacin on lipid and lipoprotein levels and glycemic control in patients with diabetes and peripheral arterial disease: the ADMIT study. A randomized trial: Arterial Disease Multiple Intervention Trial. JAMA 2000;284(10):1263-1270.
  18. Gerber MT, Mondy KE, Yarasheski KE, et al. Niacin in HIV-infected individuals with hyperlipidemia receiving potent antiretroviral therapy. Clin Infect Dis 2004;Aug 1, 39(3):419-425. Epub 2004;Jul 16.
  19. Goldberg AC. A meta-analysis of randomized controlled studies on the effects of extended-release niacin in women. Am J Cardiol 2004;Jul 1, 94(1):121-124.
  20. Goldberg A, Alagona P Jr, Capuzzi DM, et al. Multiple-dose efficacy and safety of an extended-release form of niacin in the management of hyperlipidemia. Am J Cardiol 2000;85(9):1100-1105.
  21. Goldstein MR. Use of niacin during non-ST-segment elevation acute coronary syndromes. JAMA 2005;May 4, 293(17):2092-2093. Author reply, 2093.
  22. Grundy SM, Vega GL, McGovern ME, et al. Diabetes Multicenter Research Group: efficacy, safety, and tolerability of once-daily niacin for the treatment of dyslipidemia associated with type 2 diabetes. Results of the assessment of diabetes control and evaluation of the efficacy of niaspan trial. Arch Intern Med 2002;162(14):1568-1576.
  23. Guyton JR, Capuzzi DM. Treatment of hyperlipidemia with combined niacin-statin regimens. Am J Cardiol 1998;82(12A):82U-84U.
  24. Guyton JR, Goldberg AC, Kreisberg RA, et al. Effectiveness of once-nightly dosing of extended-release niacin alone and in combination for hypercholesterolemia. Am J Cardiol 1998;82(6):737-743.
  25. Guyton JR, Blazing MA, Hagar J, et al. Extended-release niacin vs. gemfibrozil for the treatment of low levels of high-density lipoprotein cholesterol: Niaspan-Gemfibrozil Study Group. Arch Intern Med 2000;160(8):1177-1184.
  26. Hannan F, Davoren P. Use of nicotinic acid in the management of recurrent hypoglycemic episodes in diabetes. Diabetes Care 2001;24(7):1301.
  27. Kashyap ML, McGovern ME, Berra K, et al. Long-term safety and efficacy of a once-daily niacin/lovastatin formulation for patients with dyslipidemia. Am J Cardiol 2002;89(6):672-678.
  28. Komaroff AL. By the way, doctor: my CRP was 4 in April and rose to 5 in June. I've taken niacin to lower my LDL: it didn't work for that, but did increase my HDL and lower my triglycerides. My question: besides taking a statin, what can I do to lower my CRP? Harv Health Lett 2005;Jan, 30(3):8.
  29. McKenney JM, McCormick LS, Schaefer EJ, et al. Effect of niacin and atorvastatin on lipoprotein subclasses in patients with atherogenic dyslipidemia. Am J Cardiol 2001;88(3):270-274.
  30. Morris MC, Evans DA, Bienias JL, et al. Dietary niacin and the risk of incident Alzheimer's disease and of cognitive decline. J Neurol Neurosurg Psychiatry 2004;Aug, 75(8):1093-1099.
  31. Pozzilli P, Browne PD, Kolb H. Meta-analysis of nicotinamide treatment in patients with recent-onset IDDM: The Nicotinamide Trialists. Diabetes Care 1996;19(12):1357-1363.
  32. Schectman G, Hiatt J. Dose-response characteristics of cholesterol-lowering drug therapies: implications for treatment. Ann Intern Med 1996;125(12):990-1000.
  33. Sprecher DL. Raising high-density lipoprotein cholesterol with niacin and fibrates: a comparative review. Am J Cardiol 2000;86(12A):46L-50L.
  34. Taylor AJ, Sullenberger LE, Lee HJ, et al. Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol (ARBITER) 2: a double-blind, placebo-controlled study of extended-release niacin on atherosclerosis progression in secondary prevention patients treated with statins. Circulation 2004;Dec 7, 110(23):3512-3517. Epub 2004;Nov 10.
  35. Whitney EJ, Krasuski RA, Personius BE, et al. A randomized trial of a strategy for increasing high-density lipoprotein cholesterol levels: effects on progression of coronary heart disease and clinical events. Ann Intern Med 2005;Jan 18, 142(2):95-104.
  36. Wild S, Byrne CD. The role of treatment to increase HDL-cholesterol and decrease triglyceride concentrations in prevention of coronary heart disease in Type 2 diabetes. Diabet Med 2004;Sep, 21(Suppl 4):8-11.
  37. Wink J, Giacoppe G, King J. Effect of very-low-dose niacin on high-density lipoprotein in patients undergoing long-term statin therapy. Am Heart J 2002;143(3):514-518.
  38. Wolfe ML, Vartanian SF, Ross JL, et al. Safety and effectiveness of Niaspan when added sequentially to a statin for treatment of dyslipidemia. Am J Cardiol 2001;87(4):476-479, A7.
  39. Wong SF, Jakowatz JG, Taheri R. Management of hypertriglyceridemia in patients receiving interferon for malignant melanoma. Ann Pharmacother 2004;Oct, 38(10):1655-1659. Epub 2004;Aug 10.

Last updated July 14, 2005