Skip to content

Coming soon. The store is not open yet.

Menu
Full Measure

Glossary

What are niacin equivalents (NE)?

Written by the Full Measure editorial team, which sells supplements. Approved for publication by the Full Measure owners. Updated .

Drafted with AI assistance from the sources listed below. How we write these

Quick answer

Niacin equivalents (NE) count both niacin and the niacin the body makes from tryptophan, an amino acid in protein. 1 mg NE equals 1 mg of niacin or 60 mg of tryptophan. Niacin's Daily Value is 16 mg NE, but Supplement Facts labels show the amount simply in mg.1,2

Key facts

  • The formula is mg NE = mg niacin + (mg tryptophan ÷ 60).1
  • The adult RDA is 16 mg NE for men and 14 mg NE for women, rising to 18 mg NE in pregnancy.2
  • The 1 to 60 rate is an average; how well people turn tryptophan into niacin varies considerably.2
  • People short of riboflavin, vitamin B6 or iron convert less tryptophan, because the enzymes involved depend on those nutrients.2
  • Niacin's Daily Value changed from 20 mg to 16 mg NE in the 2016 label rule.1

Why a combined unit

Niacin in food is mostly nicotinic acid and nicotinamide, and the body also makes it from tryptophan once its needs for building protein are met. Counting niacin alone would undercount what a protein rich diet provides, so the RDA is set in niacin equivalents.1,2

NIH gives turkey as an example: a 3 ounce portion of turkey breast has about 180 mg of tryptophan, which could be equivalent to 3 mg of niacin.2

Worked examples from FDA guidance

Converting niacin and tryptophan in a supplement serving1
Per servingCalculationNiacin on the label% DV
14 mg niacin, no tryptophan14 + 0 = 14 mg NE14 mg88%
14 mg niacin and 240 mg tryptophan14 + (240 ÷ 60) = 18 mg NE18 mg113%

In both cases the panel prints the result as plain mg, and the %DV is worked out against 16 mg NE.1

The upper limit uses plain mg

The adult Tolerable Upper Intake Level for niacin is 35 mg a day. It applies only to supplemental niacin, not to niacin or tryptophan in food, and it was set from the amount linked to skin flushing.2

Flushing comes from nicotinic acid. Nicotinamide does not cause it, but the limit covers both forms.2

High dose niacin and medicines

The 35 mg limit does not apply to people given higher doses under medical supervision. If you take niacin above that amount, or take the tuberculosis medicines isoniazid or pyrazinamide, which interfere with making niacin from tryptophan, talk to your doctor or pharmacist.2

Questions people ask

Why does my label say mg and not mg NE?

The FDA set the Daily Value in mg NE but kept mg as the unit printed on labels. The %DV is still calculated against 16 mg NE.1

Does the niacin figure on a supplement include tryptophan?

Only when the product contains tryptophan. FDA's method adds the tryptophan divided by 60 to the niacin; a product with no tryptophan lists its niacin alone.1

See what we make

Every product shows its whole label and what its lab report covers. The store opens soon.

See the Full Measure line

Sources

  1. U.S. Food and Drug Administration. Converting Units of Measure for Folate, Niacin, and Vitamins A, D, and E on the Nutrition and Supplement Facts Labels: Guidance for Industry. August 2019. Opened 2026-10-07.
  2. NIH Office of Dietary Supplements. Niacin: Fact Sheet for Health Professionals. Updated November 18, 2022. Opened 2026-10-07.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.