The young grasses of these plants are not the same as the grains (that contain gluten) found when the plant matures. For this reason, the Food and Drug Administration will allow wheat or barley grass (or grass juice) as an ingredient in a labeled gluten-free product as long as the final product contains <20 parts per million gluten, INCLUDING the presence of any gluten due to cross contact with gluten-containing grains.

If a person with a gluten-related disorder wants to consume a labeled gluten-free product that contains wheat grass or barley grass, it is recommended that they verify the manufacturer is testing for gluten content using the R5 ELISA test.¹

BOTTOM LINE: It is very difficult to guarantee that wheat or barley grass is 100% free of seeds, in other words, absolutely pure and free of gluten. My own recommendation is to avoid products with wheat grass or barley grass (or their juices) even if they are labeled gluten free and being tested with the R5 ELISA for gluten. It’s easy to find a similar product that does not contain wheat or barley grass (or juices) to avoid these potentially risky ingredients. Overall, whole fruits and vegetables contain better sources of vitamins and minerals and are less expensive.

1. Gluten Free Dietitian. https://www.glutenfreedietitian.com/can-products-containing-wheat-and-barley-grass-be-labeled-gluten-free/ 

Revised and published online October 2, 2018.

Reviewed June 30, 2025.