Intestine supplements come from the duodenum of cows or pigs and are sold as glandular products. Some traditional and alternative medicine systems use them, based on the belief that eating animal tissue can shore up the same organ in the human body. No reliable evidence shows these oral extracts supply useful digestive enzymes or improve gastrointestinal health. Clinical studies are missing, and health authorities like the NIH do not endorse these products for any particular use.
Users typically take capsules with meals, following the dose on the label. Manufacturing processes vary, so the amount of active ingredients is not standardized. This makes effects unpredictable from one product to the next.
Contamination and allergic reactions are possible. No well-documented drug interactions exist.