Wheatgrass is young wheat grown to the grass stage — shoots about 15 to 18 centimetres tall — then cut and juiced, usually drunk in small shot-sized quantities. It is marketed as a concentrated health tonic, and it is indeed dense in chlorophyll, vitamins A, C, and E, iron, magnesium, and amino acids for its calories. Enthusiasts credit it with detoxifying and energising effects that go well beyond the evidence; the honest assessment is that it is a nutritious green juice, not a miracle. The fibre is left behind in juicing, and people with wheat allergy or coeliac disease should note that the grass contains little gluten but is not certified gluten-free. Freshness matters — it oxidises within minutes of juicing.