Secondary Hyperparathyroidism (sHPT) is a secondary effect of diseases outside theparathyroid glands which causes a decrease in calcium levels and an increase in the work of theparathyroid glands in increasing the body's calcium levels. This literature review aimed todetermine the effect of CaCO 3 contained in eggshells on the PTH profile in secondaryhyperparathyroidism and its side effects. The journals used in the writing of this article weresourced from PubMed, Embase, Medline, and Google Scholar using keywords and the PRISMA method. Based on the results of the study, it was known that the shell of a domestic chicken egg(Gallus domesticus) contains approximately 97% CaCO 3 . The potential of eggshell powdercontaining CaCO 3 was to reduce parathyroid hormone (PTH) in sHPT and increased calciumlevels by binding mechanisms and forming insoluble complexes with phosphate in the intestine,but the effect of other eggshell substances was still limited. Based on this, it can be concludedthat eggshell powder could play a role in lowering the PTH hormone in secondaryhyperparathyroidism and increasing calcium levels in the blood with minimal side effects.However, further clinical trials are still needed to evaluate the clinical effects. Keywords: Secondary hyperparathyroidism; Eggshell; Calcium carbonate (CaCO?), Parathyroidhormone