Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for NIACINAMIDE are as follows:

Likely effective for…

• A disease cause by niacin deficiency (pellagra). Niacinamide prescription products are US FDA approved for preventing and treating pellagra. It’s sometimes preferred over niacin because it doesn’t cause flushing, a side effect of niacin treatment.

Possibly effective for…

• Acne. Applying a cream containing niacinamide seems to improve the appearance of skin in people with acne.
• Diabetes. Taking niacinamide by mouth might help slow the progression of type 1 diabetes. But it doesn’t seem to prevent diabetes.
• High levels of phosphate in the blood (hyperphosphatemia). In people who need hemodialysis due to kidney failure and have high levels of phosphate, taking niacinamide by mouth seems to help decrease phosphate levels.
• Osteoarthritis. Taking niacinamide by mouth seems to improve joint flexibility and reduce pain and swelling in people with osteoarthritis.

Possibly ineffective for…

• Brain tumor. Taking niacinamide by mouth while undergoing chemotherapy doesn’t seem to benefit people with brain tumors.

There is interest in using niacinamide for a number of other purposes, but there isn’t enough reliable information to say whether it might be helpful.

When taken by mouth: Niacinamide is likely safe when used appropriately. Niacinamide-containing foods or supplements are safe when taken in doses lower than 35 mg daily. Prescription products containing higher doses of niacinamide are safe when taken as directed. Niacinamide is possibly safe when taken in doses up to 900-1500 mg daily. It might cause side effects such as stomach upset, gas, dizziness, headache, and rash.

When applied to the skin: Niacinamide is possibly safe. Niacinamide cream might cause mild burning, itching, or redness.

Special precautions & warnings:

Pregnancy and breast-feeding: Niacinamide is likely safe when taken in recommended amounts. The maximum recommended amount while pregnant or breast-feeding is 30 mg daily for those 14-18 years of age, and 35 mg daily for those 19 years of age and older.

Children: Niacinamide is likely safe when taken by mouth in the recommended amounts by age. Children should avoid taking niacinamide doses above the daily upper limits, which are 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.

Diabetes: Niacinamide might increase blood sugar. People with diabetes who take niacinamide should check their blood sugar regularly.

Gallbladder disease: Niacinamide might make gallbladder disease worse.

Kidney dialysis: Taking niacinamide seems to increase the risk of low platelet levels in people with kidney failure who are on dialysis.

Stomach or intestinal ulcers: Niacinamide might make ulcers worse. Don’t use it if you have ulcers.

Moderate

Be cautious with this combination.

Carbamazepine (Tegretol)

Carbamazepine is broken down by the body. Niacinamide might decrease how fast the body breaks down carbamazepine. But it isn’t clear if this is a major concern.

Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)

Niacinamide might slow blood clotting. Taking niacinamide along with medications that also slow blood clotting might increase the risk of bruising and bleeding.

Primidone (Mysoline)

Primidone is broken down by the body. Niacinamide might decrease how fast the body breaks down primidone. But there isn’t enough information to know if this is a major concern.

Herbs and supplements that might slow blood clotting

Niacinamide 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.

There are no known interactions with foods.

In supplements, niacinamide might be listed on the label in niacin equivalents (NE). 1 mg of niacinamide is the same as 1 mg NE. Niacinamide is found in many vitamin B complex supplements with other B vitamins. It’s also used in many topical creams and gels.

Niacinamide 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 adult males, the RDA is 16 mg NE. In adult females, 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.