Wheat grass juice comes from the freshly sprouted leaves of the common wheat plant, *Triticum aestivum*. People harvest the grass when it’s young, typically 7 to 10 days old, and press it into a green juice. The chlorophyll content gives it a deep green color.
Wheat grass juice contains vitamin K, which can interfere with blood-thinning medications like warfarin. If you take such drugs, keep your intake consistent and talk to a doctor. The grass itself is gluten-free because it’s harvested before the grain develops. Cross-contamination during processing is possible, though, so people with celiac disease should look for certified gluten-free products.
Many people drink it for a perceived boost in energy and immune function. Trials supporting these effects are small and inconclusive. The juice also supplies chlorophyll, amino acids, and some antioxidants, but no robust evidence confirms significant health benefits.