Thymus supplements are powdered or extracted animal thymus glands, usually from cows or pigs. Makers claim these support the immune system, but reliable sources like the NIH and MedlinePlus find little proof that oral thymus peptides absorb well or change immune function in healthy people. Any reported benefits remain speculative.
People typically take thymus as capsules or tablets, often alongside a meal. Scientists have not shown that food improves absorption of the peptides.
Be cautious if you have an autoimmune condition such as lupus or rheumatoid arthritis. The extract could theoretically overstimulate the immune system. It might also interfere with immunosuppressive drugs or raise risks for organ transplant recipients. Talk with a healthcare professional before using thymus if you take immunosuppressants, have an autoimmune disorder, or are pregnant or nursing.