Barley grass supplements are made from the dried juice, or essence, of organically grown young barley grass. The juice is extracted from the leaves and dehydrated at room temperature through a patented spray-drying process, producing a fine powder. The powder may be mixed with water and consumed as a drink or compressed into tablet form. In promotional literature, barley grass is described as a rich source of protein, minerals, vitamins, enzymes, and chlorophyll, and is compared favorably with a variety of foods. However, these comparisons typically use 100 grams of barley powder, an amount far above practical consumption levels. At recommended consumption levels, barley essence is a good source of vitamin C, beta-carotene, and chlorophyll, and provides significant amounts of potassium, calcium, magnesium, and iron.
For teenagers and adults, a typical daily dosage recommendation is 2 to 6 grams, mixed with cold water, 2 to 3 times per day. Barley essence is not associated with any toxicity, and appears to be safe at this dosage range. Mild side effects, such as diarrhea, constipation, and aggravation of existing skin conditions, may occur in some individuals, but generally clear with reduction of dosage.