Peptides are short chains of amino acids that serve as building blocks of proteins and play varied roles in the body, including hormone production and cell signaling. In the context of bodybuilding, certain peptides—such as growth hormone-releasing peptides (GHRPs), insulin-like growth factor-1 (IGF-1), and others—have gained popularity for their purported ability to enhance muscle growth, recovery, and fat loss. There is scientific evidence, mainly from animal studies and a limited number of human trials, suggesting that some peptides can stimulate the release of growth hormone, which may contribute to increased muscle mass and improved recovery. For example, GHRPs and IGF-1 have shown anabolic effects in controlled settings.

However, high-quality, large-scale clinical trials in athletes or healthy individuals are lacking, and most available data are derived from studies on medical conditions (such as growth hormone deficiency or muscle wasting diseases) rather than healthy bodybuilders. Moreover, the use of many such peptides for bodybuilding purposes is not approved by regulatory agencies, and their safety profiles in this context remain uncertain. Despite anecdotal reports and growing use in the bodybuilding community, the scientific evidence supporting the efficacy and safety of peptides for bodybuilding is moderate at best. More rigorous research is needed to confirm their benefits and risks in this specific population.