Parathyroid supplements come from cow parathyroid glands and contain parathyroid hormone (PTH). PTH is a peptide that helps control calcium and phosphorus levels inside the body. But PTH is a protein. The stomach and small intestine break it down during digestion. Oral supplements cannot raise PTH levels in the blood.
Marketers sometimes claim these products support bone health and calcium metabolism. There is no credible evidence behind those claims. An oral parathyroid supplement behaves like any other food protein. It does not survive digestion whole and cannot offer the same effects as the body's own PTH.
These supplements raise theoretical safety concerns. People with kidney problems, existing parathyroid disorders, or those on medicines that shift calcium balance should be especially careful. Contamination with other animal tissues is another risk.