
Background
Niacin is required for the proper function of fats and sugars in the body and to maintain healthy cells. At high doses, niacin might help people with heart disease because of its effects on blood clotting. It might also improve levels of fats called triglycerides in the blood.
Prescription forms of niacin are approved by the US FDA for abnormal cholesterol levels and for preventing vitamin B3 deficiency and related conditions such as pellagra. People use niacin supplements for metabolic syndrome, heart disease, cataracts, high blood pressure, and many other conditions, but there is no good scientific evidence to support most of these other uses.
Do not confuse niacin with NADH, niacinamide, inositol nicotinate, IP-6, or tryptophan. These are not the same.
Safety Safety definitions
A common side effect of niacin is a flushing reaction. This might cause burning, itching, and redness of the face, arms, and chest, as well as headaches. Starting with small doses and taking 325 mg of aspirin before each dose of niacin may help. This reaction usually goes away as the body gets used to niacin.
Special Precautions & Warnings:
Pregnancy and breast-feeding: Niacin is likely safe when taken by mouth while pregnant and breast-feeding. The maximum recommended amount of niacin while pregnant or breast-feeding is 30 mg daily in those under 18 years of age, and 35 mg daily for those 19 years and older.Children: Niacin is likely safe when taken by mouth in doses below the tolerable upper intake level (UL) by age. The UL is 10 mg for children 1-3 years of age, 15 mg for children 4-8 years of age, 20 mg for children 9-13 years of age, and 30 mg for children 14-18 years of age.
Allergies: Niacin might worsen allergies by causing histamine to be released. Histamine is the chemical responsible for allergic symptoms.
Chest pain (angina): Niacin should be used cautiously in people with angina.
Diabetes: Niacin might increase blood sugar. People with diabetes who take niacin should check their blood sugar carefully.
Gallbladder disease: Niacin might make gallbladder disease worse.
Gout: Large amounts of niacin might increase the risk for gout.
Kidney disease: Niacin might accumulate in people with kidney disease. This might cause harm.
Liver disease: Taking high doses of niacin might increase liver damage. Don't use large amounts if you have liver disease.
Low blood pressure: Taking niacin in high doses might lower blood pressure and worsen this condition.
Stomach or intestinal ulcers: Niacin might make ulcers worse. Don't use large amounts if you have ulcers.
Surgery: Niacin might interfere with blood sugar control during and after surgery. Speak with your healthcare provider about whether you should stop taking niacin before a scheduled surgery.
Fatty deposits around tendons (tendon xanthomas): Niacin might increase the risk of infections in xanthomas.
Thyroid disorders: Thyroxine is a hormone produced by the thyroid gland. Niacin might lower blood levels of thyroxine. This might worsen symptoms of certain thyroid disorders.
Effectiveness
- Abnormal levels of cholesterol or blood fats (dyslipidemia). Taking niacin prescription products by mouth in doses of 500 mg or more improves cholesterol levels in people with abnormal cholesterol. Dietary supplement forms of niacin usually come in lower doses and don't seem to improve blood fat levels.
- A disease caused by niacin deficiency (pellagra). Niacin prescription products are US FDA approved for preventing and treating pellagra.
- Abnormal levels of blood fats in people with HIV/AIDS. Taking prescription niacin products by mouth seems to improve levels of cholesterol and blood fats called triglycerides in people with this condition. It is unclear if niacin supplements are helpful.
- A grouping of symptoms that increase the risk of diabetes, heart disease, and stroke (metabolic syndrome). Taking prescription niacin products by mouth seems to increase levels of high-density lipoprotein (HDL or "good") cholesterol and reduce levels of blood fats called triglycerides in people with metabolic syndrome. It is unclear if niacin supplements are helpful.
- Heart disease. Taking niacin by mouth does not prevent heart attack or stroke in people with or without heart disease.
Dosing & administration
Niacin is also found in many foods, including meat, fish, milk, eggs, vegetables, and cereals. The amount that should be consumed on a daily basis is called the recommended dietary allowance (RDA). In males 14 years and older, the RDA is 16 mg NE. In females 14 years and older, the RDA is 14 mg NE. While pregnant, the RDA is 18 mg NE. While breast-feeding, the RDA is 17 mg NE. In children, the RDA depends on age. Speak with a healthcare provider to find out what dose might be best for a specific condition.
Interactions with pharmaceuticals
Alcohol (Ethanol)
Interaction Rating=Moderate Be cautious with this combination.
Niacin can cause flushing and itchiness. Consuming alcohol along with niacin might make the flushing and itching worse. There is also some concern that consuming alcohol with niacin might increase the chance of having liver damage.
Allopurinol (Zyloprim)
Interaction Rating=Moderate Be cautious with this combination.
Allopurinol is used to treat gout. Taking large doses of niacin might worsen gout and decrease the effects of allopurinol.
Aspirin
Interaction Rating=Minor Be watchful with this combination.
Aspirin is often used to reduce the flushing caused by niacin. These low doses of aspirin don't seem to cause any issues when taken with niacin. But taking higher doses of aspirin, such as 1 gram daily, might decrease how fast the body gets rid of niacin. This could cause there to be too much niacin in the body and possibly lead to side effects. Stick with lower doses of aspirin, such as 325 mg or less.
Gemfibrozil (Lopid)
Interaction Rating=Moderate Be cautious with this combination.
Taking niacin along with gemfibrozil might increase the risk for muscle damage in some people. Use with caution.
Medications for diabetes (Antidiabetes drugs)
Interaction Rating=Moderate Be cautious with this combination.
High doses of niacin might increase blood sugar levels. Taking niacin along with diabetes medications might reduce the effects of these medications. Monitor your blood sugar closely.
Medications for high blood pressure (Antihypertensive drugs)
Interaction Rating=Moderate Be cautious with this combination.
Niacin might lower blood pressure. Taking niacin along with medications that lower blood pressure might cause blood pressure to go too low. Monitor your blood pressure closely.
Medications that can harm the liver (Hepatotoxic drugs)
Interaction Rating=Moderate Be cautious with this combination.
Niacin might harm the liver. Some medications can also harm the liver. Taking niacin along with a medication that can harm the liver might increase the risk of liver damage.
Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)
Interaction Rating=Moderate Be cautious with this combination.
Niacin might slow blood clotting. Taking niacin along with medications that also slow blood clotting might increase the risk of bruising and bleeding.
Medications used for lowering cholesterol (Bile acid sequestrants)
Interaction Rating=Moderate Be cautious with this combination.
Some medications called bile acid sequestrants can decrease how much niacin the body absorbs. This might reduce the effects of niacin. Take niacin and these medications at least 4-6 hours apart.
Medications used for lowering cholesterol (Statins)
Interaction Rating=Moderate Be cautious with this combination.
Taking niacin along with statins might increase the risk for muscle damage in some people. Use with caution.
Nicotine patch (Nicoderm)
Interaction Rating=Moderate Be cautious with this combination.
Niacin can sometimes cause flushing and dizziness. Nicotine patches can also cause flushing and dizziness. Taking niacin and using a nicotine patch may increase the risk of flushing and dizziness.
Probenecid (Benemid)
Interaction Rating=Moderate Be cautious with this combination.
Probenecid is used to treat gout. Taking large doses of niacin might worsen gout and decrease the effects of probenecid.
Sulfinpyrazone (Anturane)
Interaction Rating=Moderate Be cautious with this combination.
Sulfinpyrazone is used to treat gout. Taking large doses of niacin might worsen gout and decrease the effects of sulfinpyrazone.
Thyroid hormone
Interaction Rating=Moderate Be cautious with this combination.
The body naturally produces thyroid hormones. Niacin might decrease thyroid hormone levels. Taking niacin with thyroid hormone pills might decrease the effects of thyroid hormone.
Interactions with herbs & supplements
Chromium: Taking niacin and chromium together might lower blood sugar. If you have diabetes and take chromium and niacin supplements together, monitor your blood sugar to make sure it doesn't get too low.
Herbs and supplements that might harm the liver: Niacin might harm the liver. Taking it with other supplements that can also harm the liver might increase the risk of liver damage. Examples of supplements with this effect include garcinia, greater celandine, green tea extract, kava, and kratom.
Herbs and supplements that might lower blood pressure: Niacin might lower blood pressure. Taking it with other supplements that have the same effect might cause blood pressure to drop too much. Examples of supplements with this effect include andrographis, casein peptides, L-arginine, niacin, and stinging nettle.
Herbs and supplements that might slow blood clotting: Niacin might slow blood clotting and increase the risk of bleeding. Taking it with other supplements with similar effects might increase the risk of bleeding in some people. Examples of supplements with this effect include garlic, ginger, ginkgo, nattokinase, and Panax ginseng.
Selenium: Taking niacin along with antioxidants, including selenium, might reduce the beneficial effects that niacin has on cholesterol levels.
Vitamin C: Taking niacin along with antioxidants, including vitamin C, might reduce the beneficial effects that niacin has on cholesterol levels.
Vitamin E: Taking niacin along with antioxidants, including vitamin E, might reduce the beneficial effects that niacin has on cholesterol levels.
Zinc: People who are malnourished and have niacin deficiency, such as those with alcohol use disorder, make extra niacin if they take zinc. There might be an increased risk of niacin-related side effects such as flushing and itching if niacin and zinc are taken together.
Interactions with foods
Products
View all products- Nicotinamide ascorbate (Vitamin B3) 256 mg equiv. ascorbic acid 151 mg equiv. nicotinamide 105 mg
- Calcium ascorbate dihydrate (Vitamin C) 780 mg equiv. ascorbic acid 640 mg
- Citrus bioflavonoids (Hesperidin) 18 mg
- Cysteine hydrochloride 9.7 mg
- Sodium ascorbate (Vitamin C) 139 mg equiv. ascorbic acid 123 mg
- Magnesium ascorbate monohydrate (Vitamin C) 55 mg equiv. ascorbic acid 49 mg
- Potassium ascorbate dihydrate (Vitamin C) 24 mg equiv. ascorbic acid 17 mg
- Nicotinamide riboside chloride (Vitamin B3) 100 mg equiv. ribose 52 mg
- D-Ribose 4.6 g
- Acetyl levocarnitine hydrochloride (Acetyl-L-carnitine) 1 g
- Calcium pyruvate 666 mg equiv. calcium 100 mg
- Magnesium citrate 647 mg equiv. magnesium 100 mg
- Calcium pantothenate (Vitamin B5) 65 mg equiv. pantothenic acid 60 mg
- Taurine 50 mg
- Biotin 1 mg
- Nicotinamide (Vitamin B3) 222 mg
- Nicotinic acid (Vitamin B3) 5.55 mg
- Cyanocobalamin (Vitamin B12) 111 μg
- Retinyl palmitate 557 μg equiv. vitamin A 300 μg RE
- Cholecalciferol 2.78 μg equiv. vitamin D3 111 IU
- d-alpha-Tocopheryl acetate 40.9 mg equiv. vitamin E 54.3 IU
- Zinc amino acid chelate 55.6 mg equiv. zinc 11.1 mg
- Ascorbic acid (Vitamin C) 111 mg
- R,S-alpha lipoic acid 22.2 mg
- Levocarnitine fumarate (L-carnitine) 22.2 mg
- L-tyrosine 55.6 mg
- Thiamine hydrochloride (Vitamin B1) 55.6 mg
- Riboflavin (Vitamin B2) 22.2 mg
- Calcium pantothenate (Vitamin B5) 111 mg equiv. pantothenic acid 102 mg
- Pyridoxal 5-phosphate (P5P) 33.3 mg equiv. pyridoxine 22.8 mg
- Folic acid 200 μg
- Biotin 55.5 μg
- Lecithin 111 mg
- Chromium picolinate 402.25 μg equiv. chromium 50 μg
- Potassium phosphate - monobasic 38.7 mg equiv. potassium 11.1 mg
- Magnesium phosphate pentahydrate 53.8 mg equiv. magnesium 11.1 mg
- Calcium ascorbate (Vitamin C) 111.1 mg equiv. ascorbic acid 91.3 mg
- Calcium hydrogen phosphate dihydrate 95.4 mg equiv. calcium 22.2 mg
- Manganese amino acid chelate 1.1 g equiv. manganese 111 μg
- Selenomethionine 27.8 μg equiv. selenium 11.1 μg
- Copper gluconate 79.3 μg equiv. copper 11.1 μg
- L-glutamine 55.6 mg
- L-glycine 1.8 g
- Taurine 111 mg
- Cysteine hydrochloride 11.1 mg
- Citrus bioflavonoids (Hesperidin) 55.5 mg
- Camellia sinensis ext. 5.55 mg
- Nicotinamide (Vitamin B3) 220 mg
- Thiamine hydrochloride (Vitamin B1) 56 mg
- Pyridoxine hydrochloride (Vitamin B6) 50 mg
- Riboflavin (Vitamin B2) 30 mg
- Cyanocobalamin (Vitamin B12) 400 μg
- Calcium pantothenate (Vitamin B5) 105 mg
- Taurine 125 mg
- L-glutamine 100 mg
- Ascorbic acid (Vitamin C) 75 mg
- Potassium phosphate - dibasic 50 mg equiv. potassium 22 mg
- Choline bitartrate 50 mg
- Lecithin 50 mg
- L-lysine 50 mg
- Potassium aspartate 50 mg equiv. potassium 10 mg
- Calcium hydrogen phosphate dihydrate 49 mg equiv. calcium 12 mg
- Magnesium citrate 44 mg equiv. magnesium 7 mg
- Zinc sulphate monohydrate 42 mg equiv. zinc 15 mg
- Tocopherols concentrate - mixed (high-alpha type) (Vitamin E) 15 mg equiv. d-alpha-tocopherol 2.5 mg
- Borax 4.4 mg equiv. boron 500 μg
- Chromium nicotinate 500 μg equiv. chromium 50 μg
- Folic acid 395 μg
- Selenomethionine 63 μg equiv. selenium 25 μg
- Manganese sulphate monohydrate 55 μg equiv. manganese 18 μg
- Biotin 50 μg
- Potassium iodide 46 μg equiv. iodine 35 μg
- Copper gluconate 43 μg equiv. copper 6 μg
- Cholecalciferol (Vitamin D3) 1 μg
- Iron bisglycinate 50 mg equiv. iron 10 mg
- Dunaliella salina ext. 67 mg
- Nicotinamide (Vitamin B3) 220 mg
- Nicotinic acid (Vitamin B3) 5 mg
- Thiamine hydrochloride (Vitamin B1) 50 mg equiv. thiamine 43.26 mg
- Pyridoxine hydrochloride (Vitamin B6) 50.13 mg equiv. pyridoxine 40 mg
- Pyridoxal 5-phosphate (P5P) 10 mg equiv. pyridoxine 6.38 mg
- Riboflavin 5-phosphate sodium (Activated B2) 27.4 mg equiv. riboflavin 20 mg
- Mecobalamin (Vitamin B12) 500 μg
- Selenomethionine 64.6 μg equiv. selenium 26 μg
- Retinol acetate 885 μg equiv. vitamin A 750 μg RE
- Calcium pantothenate (Vitamin B5) 100 mg equiv. pantothenic acid 88 mg equiv. calcium 8.4 mg
- Calcium folinate (Activated folate) 278 μg equiv. folinic acid 200 μg
- Levomefolate calcium (Activated folate) 217 μg equiv. levomefolic acid 200 μg
- Calcium ascorbate dihydrate (Vitamin C) 121 mg equiv. ascorbic acid 100 mg equiv. calcium 11.4 mg
- Cholecalciferol 2.5 μg equiv. vitamin D3 100 IU
- d-alpha-Tocopheryl acid succinate 28 mg equiv. vitamin E 34 IU
- Tocopherols concentrate - mixed (low-alpha type) (Vitamin E) 13.5 mg
- R,S-alpha lipoic acid 10 mg
- Biotin 150 μg
- Ananas comosus (Bromelain) 6 mg
- Choline bitartrate 40 mg
- Citrus bioflavonoids (Hesperidin) 5 mg
- Cysteine hydrochloride 21.74 mg
- L-glutamine 40 mg
- Citrus bioflavonoids (Hesperidin) 5 mg
- Inositol 25 mg
- Lecithin 15 mg
- L-lysine 35 mg
- Rutin (Rutoside) 10 mg
- Taurine 85 mg
- Chromium nicotinate 208.3 μg equiv. chromium 25 μg
- Cupric citrate 17 μg equiv. copper 6 μg
- Potassium iodide (Iodine) 40.6 μg equiv. iodine 31 μg equiv. potassium 9.55 μg
- Magnesium phosphate pentahydrate 48.4 mg equiv. magnesium 10 mg
- Manganese gluconate 438.6 μg equiv. manganese 50 μg
- Potassium phosphate - monobasic 48.7 mg equiv. potassium 14 mg
- Zinc gluconate 109.9 mg equiv. zinc 14.4 mg
- Molybdenum trioxide 75 μg equiv. molybdenum 50 μg
- Rosa canina powder 10 mg
- Nicotinamide (Vitamin B3) 200 mg
- Ascorbic acid (Vitamin C) 100 mg
- d-alpha-Tocopheryl acid succinate 82.64 mg equiv. vitamin E 100 IU
- Tocopherols concentrate - mixed (low-alpha type) (Vitamin E) 14.7 mg
- Retinol acetate 431.2 μg equiv. vitamin A 375 μgRE
- Cyanocobalamin (Vitamin B12) 400 μg
- Cholecalciferol 2.5 μg equiv. vitamin D3 100 IU
- Zinc amino acid chelate 50 mg equiv. zinc 10 mg
- Thiamine hydrochloride (Vitamin B1) 50 mg
- Riboflavin (Vitamin B2) 50 mg
- Calcium pantothenate (Vitamin B5) 100 mg equiv. pantothenic acid 91.6 mg equiv. calcium 8.39 mg
- Pyridoxine hydrochloride (Vitamin B6) 50 mg equiv. pyridoxine 41.14 mg
- Folic acid 400 μg
- Biotin 100 μg
- Phytomenadione (Vitamin K1) 30 μg
- Borax 8.82 mg equiv. boron 1 mg
- Calcium citrate 237 mg equiv. calcium 50 mg
- Chromium nicotinate 416.67 μg equiv. chromium 50 μg
- Copper gluconate 1.43 mg equiv. copper 200 μg
- Magnesium oxide - heavy 41.46 mg equiv. magnesium 25 mg
- Manganese amino acid chelate 5 mg equiv. manganese 1 mg
- Molybdenum trioxide 113 μg equiv. molybdenum 75 μg
- Selenomethionine 64.58 μg equiv. selenium 26 μg
- Citrus bioflavonoids (Hesperidin) 50 mg
- Choline bitartrate 50 mg equiv. choline 20 mg
- Myo-inositol 50 mg
- Beta-carotene (Carotenoids) 4 mg
- Nicotinamide (Vitamin B3) 200 mg
- Glucosamine sulphate potassium chloride 663 mg equiv. glucosamine sulphate 500 mg
- Lecithin 100 mg
- Boswellia serrata ext. 57 mg
- Curcuma longa ext. 4 mg
- Sodium ascorbate (Vitamin C) 112.5 mg equiv. ascorbic acid 100 mg
- Magnesium orotate dihydrate 103.6 mg equiv. magnesium 6.6 mg
- Manganese amino acid chelate 25 mg equiv. manganese 5 mg
- Cholecalciferol 2.5 μg equiv. vitamin D3 100 IU
- Silybum marianum ext. 5 mg
- Vitis vinifera ext. 1 mg
- Nicotinamide (Vitamin B3) 200 mg
- Glucosamine sulphate potassium chloride 663 mg equiv. glucosamine sulphate 500 mg equiv. potassium chloride 163 mg
- Cholecalciferol 2.5 µg equiv. vitamin D3 100 IU
- Boswellia serrata ext. 57.1 mg
- Sodium ascorbate (Vitamin C) 112.5 mg equiv. ascorbic acid 100 mg
- Lecithin 100 mg
- Magnesium orotate dihydrate 103.58 mg equiv. magnesium 6.7 mg
- Manganese amino acid chelate 25 mg equiv. manganese 5 mg
- Silybum marianum ext. 5 mg
- Vitis vinifera ext. 1 mg
- Curcuma longa ext. 4 mg
- Nicotinamide (Vitamin B3) 187.5 mg
- Calcium pantothenate (Vitamin B5) 546 mg equiv. pantothenic acid 500 mg
- Zinc gluconate 57.43 mg equiv. zinc 7.5 mg
- Retinyl acetate 206.4 μg equiv. vitamin A 175 μg RE
- Biotin 500 μg
- Urtica dioica ext. 93.75 mg
- Copper gluconate 2.7 mg equiv. copper 375 μg
- Silica - colloidal anhydrous 26.7 mg equiv. silicon 12.5 mg
- Folic acid 125 μg
- Nicotinamide (Vitamin B3) 150 mg
- Calcium folinate (Activated folate) 542 μg equiv. folinic acid 500 μg
- Hydroxocobalamin (Vitamin B12) 500 μg
- Thiamine hydrochloride (Vitamin B1) 63.5 mg equiv. thiamine 50 mg
- Riboflavin 5-phosphate sodium (Activated B2) 26.3 mg equiv. riboflavin 20 mg
- Calcium pantothenate (Vitamin B5) 218.3 mg equiv. pantothenic acid 200 mg
- Pyridoxal 5-phosphate (P5P) 31.3 mg equiv. pyridoxine 20 mg
- Inositol 100 mg
- Biotin 500 μg
- Nicotinamide (Vitamin B3) 150 mg
- Thiamine nitrate (Vitamin B1) 100 mg equiv. thiamine 81.1 mg
- Riboflavin (Vitamin B2) 50 mg
- Calcium pantothenate (Vitamin B5) 110 mg equiv. pantothenic acid 100.8 mg
- Pyridoxine hydrochloride (Vitamin B6) 75 mg equiv. pyridoxine 61.7 mg
- Folic acid 150 µg
- Cyanocobalamin (Vitamin B12) 150 µg
- Biotin 150 µg
- Choline bitartrate 137.5 mg
- Inositol 100 mg
- Camellia sinensis ext. 113.8 mg
- Nicotinamide riboside chloride (Vitamin B3) 150 mg
- Total Magnesium 360 mg
- Magnesium aspartate dihydrate 1.4 g equiv. magnesium 105 mg
- Magnesium glycerophosphate 1.15 g equiv. magnesium 127 mg
- Magnesium citrate 792.1 mg equiv. magnesium 128 mg
- Taurine 3 g
- Potassium aspartate 47.6 mg equiv. potassium 10 mg