
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 (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
- 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 (Vitamin B3) 130 mg
- Riboflavin 5-phosphate sodium (Activated B2) 25 mg equiv. riboflavin 19.7 mg
- Pyridoxal 5-phosphate monohydrate (P5P) 23.5 mg equiv. pyridoxine 15 mg
- Calcium pantothenate (Vitamin B5) 196.5 mg equiv. pantothenic acid 180 mg
- Thiamine hydrochloride (Vitamin B1) 63.6 mg equiv. thiamine 50 mg
- Biotin 500 μg
- Nicotinamide (Vitamin B3) 130 mg
- Calcium pantothenate (Vitamin B5) 196.5 mg equiv. pantothenic acid 180 mg
- Thiamine hydrochloride (Vitamin B1) 63.6 mg equiv. thiamine 50 mg
- Co-methylcobalamin (Vitamin B12) 400 µg
- Biotin 500 µg
- Riboflavin 5-phosphate sodium (Activated B2) 25 mg equiv. riboflavin 19.7 mg
- Pyridoxal 5-phosphate (P5P) 23.5 mg equiv. pyridoxine 15 mg
- Levomefolate calcium (Activated folate) 433 µg equiv. levomefolic acid 400 µg
- Nicotinamide (Vitamin B3) 130 mg
- Pyridoxal 5-phosphate (P5P) 23.5 mg equiv. pyridoxine 15 mg
- Calcium folinate (Activated folate) 513 μg equiv. folinic acid 400 μg
- Hydroxocobalamin (Vitamin B12) 400 μg
- Calcium pantothenate (Vitamin B5) 196.5 mg equiv. pantothenic acid 180 mg
- Thiamine hydrochloride (Vitamin B1) 63.6 mg equiv. thiamine 50 mg
- Biotin 500 μg
- Riboflavin 5-phosphate sodium (Activated B2) 25 mg equiv. riboflavin 19.7 mg
- Nicotinamide (Vitamin B3) 100 mg
- Nicotinic acid (Vitamin B3) 5 mg
- Beta-carotene (Carotenoids) 3 mg
- Thiamine hydrochloride (Vitamin B1) 30 mg
- Riboflavin (Vitamin B2) 20 mg
- Pyridoxine hydrochloride (Vitamin B6) 50 mg equiv. pyridoxine 41.14 mg
- Cyanocobalamin (Vitamin B12) 100 μg
- Calcium ascorbate dihydrate (Vitamin C) 110 mg equiv. ascorbic acid 90.9 mg equiv. calcium 10.3 mg
- Zinc amino acid chelate 75 mg equiv. zinc 15 mg
- Cholecalciferol (Vitamin D3) 5 μg equiv. vitamin D 200 IU
- d-alpha-Tocopheryl acid succinate 82.6 mg equiv. vitamin E 100 IU
- Calcium pantothenate (Vitamin B5) 100 mg equiv. pantothenic acid 91.6 mg equiv. calcium 8.4 mg
- Folic acid 400 μg
- Biotin 100 μg
- Choline bitartrate 25 mg
- Inositol 25 mg
- Calcium citrate tetrahydrate 84 mg equiv. calcium 17.7 mg
- Magnesium amino acid chelate 90 mg equiv. magnesium 18 mg
- Potassium phosphate - dibasic 50 mg equiv. potassium 22.5 mg
- Silica - colloidal anhydrous 32.1 mg equiv. silicon 15 mg
- Manganese amino acid chelate 20 mg equiv. manganese 2 mg
- Borax 4.41 mg equiv. boron 500 μg
- Chromium nicotinate 500 μg equiv. chromium 50 μg
- Copper sulphate pentahydrate 196.5 μg equiv. copper 50 μg
- Potassium iodide 50 μg equiv. iodine 38.2 μg
- Molybdenum trioxide 50 μg equiv. molybdenum 33.3 μg
- Selenomethionine 124.2 μg equiv. selenium 50 μg
- Phytomenadione (Vitamin K1) 50 μg
- Taurine 100 mg
- Glutamine 50 mg
- Lysine hydrochloride 50 mg
- Tagetes erecta ext. 20 mg
- Citrus bioflavonoids extract equiv. citrus bioflavonoids 50 mg
- Rutin (Rutoside) 15 mg
- Lycopene 2 mg
- Nicotinamide (Vitamin B3) 100 mg
- Thiamine hydrochloride (Vitamin B1) 100 mg
- Riboflavin (Vitamin B2) 80 mg
- Pyridoxine hydrochloride (Vitamin B6) 75 mg equiv. pyridoxine 61.7 mg
- Cyanocobalamin (Vitamin B12) 100 µg
- Calcium pantothenate (Vitamin B5) 120 mg equiv. pantothenic acid 109.9 mg
- Folic acid 400 µg
- Choline bitartrate 50 mg
- Inositol 50 mg
- Biotin 50 µg
- Ascorbic acid (Vitamin C) 200 mg
- Nicotinamide (Vitamin B3) 100 mg
- Nicotinic acid (Vitamin B3) 10 mg
- Thiamine hydrochloride (Vitamin B1) 100 mg equiv. thiamine 89.2 mg
- Riboflavin (Vitamin B2) 100 mg
- Pyridoxine hydrochloride (Vitamin B6) 100 mg equiv. pyridoxine 82.3 mg
- Cyanocobalamin (Vitamin B12) 500 µg
- Calcium pantothenate (Vitamin B5) 75 mg equiv. pantothenic acid 68.2 mg
- Calcium folinate (Activated folate) 538 µg equiv. folinic acid 400 µg
- Biotin 100 µg
- Choline bitartrate 50 mg
- Inositol 50 mg
- Nicotinamide (Vitamin B3) 100 mg
- Ascorbic acid (Vitamin C) 397 mg
- Sodium ascorbate (Vitamin C) 148 mg equiv. ascorbic acid 131 mg
- Potassium ascorbate (Vitamin C) 24 mg equiv. ascorbic acid 18 mg
- Calcium ascorbate dihydrate (Vitamin C) 515 mg equiv. ascorbic acid 426 mg
- Magnesium ascorbate monohydrate (Vitamin C) 71 mg equiv. ascorbic acid 64 mg
- Citrus bioflavonoids (Hesperidin) 17 mg
- L-cysteine 6.8 mg
- Nicotinamide (Vitamin B3) 100 mg
- Thiamine nitrate (Vitamin B1) 75 mg equiv. thiamine 60.8 mg
- Riboflavin (Vitamin B2) 50 mg
- Pyridoxine hydrochloride (Vitamin B6) 50 mg equiv. pyridoxine 41.1 mg
- Cyanocobalamin (Vitamin B12) 100 µg
- Calcium pantothenate (Vitamin B5) 81.8 mg equiv. pantothenic acid 75 mg
- Biotin 1 mg
- Folic acid 200 µg
- Inositol 25 mg
- Choline bitartrate 25 mg
- Ascorbic acid (Vitamin C) 100 mg
- Nicotinamide (Vitamin B3) 100 mg
- Thiamine hydrochloride (Vitamin B1) 75 mg
- Riboflavin (Vitamin B2) 10 mg
- Calcium pantothenate (Vitamin B5) 75 mg equiv. pantothenic acid 68.8 mg
- Pyridoxine hydrochloride (Vitamin B6) 25 mg equiv. pyridoxine 20.6 mg
- Cyanocobalamin (Vitamin B12) 30 µg
- Avena sativa ext. 25 mg
- Passiflora incarnata ext. 20 mg
- Biotin 20 µg
- Calcium ascorbate dihydrate (Vitamin C) 145 mg equiv. ascorbic acid 130 mg
- d-alpha-Tocopheryl acid succinate 41.3 mg equiv. vitamin E 50 µg
- Magnesium phosphate pentahydrate 140 mg equiv. magnesium 28.9 mg
- Calcium phosphate 100 mg equiv. calcium 37 mg
- Potassium phosphate - monobasic 117.3 mg equiv. potassium 33.7 mg
- Folic acid 150 µg
- Choline bitartrate 25 mg
- Inositol 25 mg
- Lecithin 50 mg
- Nicotinamide (Vitamin B3) 75 mg
- Potassium iodide 294 μg equiv. iodine 225 μg
- Iron bisglycinate 18.5 mg equiv. iron 5 mg
- Co-methylcobalamin (Vitamin B12) 400 μg
- Ubidecarenone (Coenzyme Q10) 100 mg
- Menaquinone 7 (Vitamin K2) 20 μg
- Choline bitartrate 486 mg
- Thiamine hydrochloride (Vitamin B1) 56 mg
- Riboflavin (Vitamin B2) 50 mg
- Manganese amino acid chelate 50 mg equiv. manganese 5 mg
- Zinc citrate dihydrate 78.35 mg equiv. zinc 25 mg
- Pyridoxine hydrochloride (Vitamin B6) 61 mg equiv. pyridoxine 50 mg
- Pyridoxal 5-phosphate (P5P) 15.4 mg equiv. pyridoxine 10 mg
- Ascorbic acid (Vitamin C) 100 mg
- Selenomethionine 186 μg equiv. selenium 75 μg
- Calcium pantothenate (Vitamin B5) 55 mg equiv. pantothenic acid 50 mg
- Chromium nicotinate 500 μg equiv. chromium 50 μg
- Sodium molybdate dihydrate 126 μg equiv. molybdenum 50 μg
- R,S-alpha lipoic acid 100 mg
- Biotin 100 μg
- Cholecalciferol 25 μg equiv. vitamin D3 1000 IU
- Beta-carotene (Carotenoids) 3 mg
- d-alpha-Tocopheryl acid succinate 200 mg
- Inositol 100 mg
- Levomefolate calcium (Activated folate) 540 μg equiv. levomefolic acid 500 μg
- Nicotinamide (Vitamin B3) 75 mg
- Tribulus terrestris ext. 20 mg
- Thiamine nitrate (Vitamin B1) 61.7 mg
- Riboflavin (Vitamin B2) 50 mg
- Calcium pantothenate 81.9 mg equiv. calcium 6.9 mg equiv. pantothenic acid 75 mg
- Pyridoxine hydrochloride (Vitamin B6) 60.8 mg equiv. pyridoxine 50 mg
- Folic acid 100 μg
- Levomefolate calcium (Activated folate) 124 μg equiv. levomefolic acid 100 μg
- Mecobalamin (Vitamin B12) 100 μg
- Ascorbic acid (Vitamin C) 100 mg
- Cholecalciferol 25 μg equiv. vitamin D3 1000 IU
- d-alpha-Tocopheryl acid succinate 10.5 mg equiv. vitamin E 12.7 IU
- Biotin 250 μg
- Inositol 50 mg
- Alpha lipoic acid 30 mg
- Lycopene 1 mg
- Calcium citrate tetrahydrate 99.53 mg equiv. calcium 21 mg
- Chromium picolinate 199.5 μg equiv. chromium 24.8 μg
- Copper gluconate 7.14 mg equiv. copper 1 mg
- Iron amino acid chelate 30 mg equiv. iron 3 mg
- Magnesium citrate 154.7 mg equiv. magnesium 25 mg
- Manganese sulphate monohydrate 1.54 mg equiv. manganese 500 μg
- Potassium phosphate - monobasic 24.5 mg equiv. potassium 7 mg
- Potassium iodide 50 μg equiv. iodine 38 μg
- Selenomethionine 186.3 μg equiv. selenium 75 μg
- Zinc amino acid chelate 50 mg equiv. zinc 10 mg
- Tribulus terrestris ext. 20 mg
- Eleutherococcus senticosus ext. 133.3 mg
- Turnera diffusa ext. 50 mg
- Withania somnifera ext. 20 mg
- Nicotinamide (Vitamin B3) 60 mg
- d-alpha-Tocopheryl acid succinate 16.5 mg equiv. vitamin E 20 IU
- Cholecalciferol (Vitamin D3) 10 µg
- Ascorbic acid (Vitamin C) 180 mg
- Cyanocobalamin (Vitamin B12) 7 µg
- Retinol palmitate (Vitamin A) 2.8 mg equiv. vitamin A 5000 IU equiv. retinol Equivalents 1500 µg
- Zinc oxide 6.2 mg equiv. zinc 5 mg
- Thiamine nitrate (Vitamin B1) 7.5 mg equiv. thiamine 6.1 mg
- Calcium pantothenate (Vitamin B5) 21.8 mg equiv. pantothenic acid 20 mg
- Riboflavin (Vitamin B2) 8.5 mg
- Pyridoxine hydrochloride (Vitamin B6) 10 mg equiv. pyridoxine 8.2 mg
- Calcium carbonate 100 mg equiv. calcium 41.8 mg
- Biotin 25 µg
- Magnesium oxide - heavy 30.6 mg equiv. magnesium 17.9 mg
- Manganese sulphate monohydrate 6.2 mg equiv. manganese 2 mg
- Potassium sulphate 55.8 mg equiv. potassium 25 µg
- Ferrous sulphate 16 mg equiv. iron 5 mg
- Folic acid 200 µg
- Inositol 25 mg
- Choline bitartrate 25 mg