Optimum Nutrition · L-glutamine · Powder

Is Optimum Nutrition Glutamine Powder underdosed?

1 serving = 5.15 g of powderDirections: 1 serving a dayLabel as of 21 Jul 2022 · NIH DSLD

Verdict

5 g a dayas the label directs

Not graded

Contains 5 g. Not graded: the ISSN's 2018 review lists glutamine among supplements with little to no evidence of working, for building muscle and for performance.

One serving gives 5 g.

What the label says

L-Glutamine per serving
5 g in 5.15 g of powder
Servings a day
1 serving a day
L-Glutamine a day, as directed
5 g
Research dose
Not graded Evidence: Not graded
Directions: Mix one heaping teaspoon of Glutamine Powder with 8 oz. of water or your favorite beverage daily as part of a healthy diet and exercise program. Intended for use in healthy adults as part of a healthy, balance diet and exercise program.
The label's directions, as printed.

More about l-glutamine: forms, timing and the studies behind the dose.

Same category, compared

All 17 L-glutamine supplements we checked, ranked by dose (commission never changes the order).

Where the reference doses come from

  1. L-Glutamine, : .
  2. Label data: National Institutes of Health, Office of Dietary Supplements. Dietary Supplement Label Database, 2026. https://dsld.od.nih.gov/. Label 270344, including its servings a day.

For a supplement taken every day we judge the most the label's directions give in a day, and show the least. Read the full methodology or the corrections log.