Peptides, particularly bioactive peptides, have been studied for their potential role in supporting testicular function and overall male reproductive health. Scientific evidence suggests that certain peptides can influence hormonal regulation, spermatogenesis, and testicular cell function. For example, research has indicated that specific peptides, such as gonadotropin-releasing hormone (GnRH) analogs, play a direct role in stimulating the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), both of which are critical for testicular activity and testosterone production. Additionally, some animal studies suggest that dietary peptides derived from sources like fish or milk may exhibit antioxidative and anti-inflammatory properties, potentially protecting testicular tissue from oxidative stress and improving sperm quality.

Despite these findings, most of the supportive evidence arises from preclinical studies or investigations of specific, pharmacologically active peptides rather than general peptide supplements. There is a lack of large-scale, high-quality human clinical trials directly linking generic peptide supplementation to improved testicular health or function. Thus, while there is a scientific rationale for certain peptides’ effects on the testes, the strength of evidence for over-the-counter peptide supplements supporting general testicular health in humans remains moderate.