No published human studies have tested CJC-1295 or ipamorelin for effects on fertility, sperm quality, or reproductive hormones. However, there is a significant and truly well-documented body of separate research on how growth hormone itself interacts with the reproductive system. Because these peptides work by raising growth hormone, these broader studies provide important, albeit indirect, context for understanding what might theoretically be at play.
CJC-1295 and ipamorelin and fertility
Growth hormone has a well-established, though secondary, role in human reproduction. This has been studied for decades, primarily in the context of growth hormone deficiency and infertility treatment, rather than growth hormone-releasing peptides such as CJC-1295 or ipamorelin specifically. A comprehensive 2023 review examining the effects of growth hormone on adult human gonads described something interesting. Growth hormone receptors are present in the testes and ovaries. Growth hormone can influence the sensitivity of the gonads to the reproductive hormones that directly control fertility, specifically FSH and LH. It does this largely through collaboration with IGF-1, rather than acting as a primary driver of reproductive function itself [1]. This same review discussed how growth hormone supplementation had been investigated as an adjunctive therapy in specific infertility treatment contexts, for both men and women. This has typically involved those who already had a documented growth hormone deficiency, rather than individuals with normal growth hormone levels seeking fertility enhancement [1].
It is important to understand what this body of research says and does not say. This is research on growth hormone itself, typically administered directly, in populations specifically selected because they had a hormonal deficiency. It does not include CJC-1295 or ipamorelin. No study has tested whether raising growth hormone indirectly through these growth hormone-releasing peptides, in individuals without a growth hormone deficiency, elicits any comparable effect on fertility.
CJC-1295 and ipamorelin and female fertility
Regarding specific effects on female fertility, the same 2023 review described a documented role for growth hormone in ovarian function. This includes its impact on ovarian follicle development, hormone production within the ovary, and the presence of growth hormone receptors on cells throughout the female reproductive tract [1]. Separate reviews of the broader reproductive physiology of growth hormone have described its use in certain assisted reproduction settings. Growth hormone has been investigated as a supplement aimed at improving egg quality and treatment response in specific patient populations undergoing fertility treatments. Regarding ipamorelin specifically, there is one significant animal study. A study on tilapia fish analysed the effects of a ghrelin agonist, ipamorelin acetate, on the reproductive axis. It found that administration led to increased numbers of developing reproductive cells, along with elevated luteinising hormone and associated sex steroid hormone in this species [2].
This is a genuine discovery worth noting. However, it derives from a study on fish, which represents a significant evolutionary and physiological distance from human female reproductive biology. No comparable study has been conducted on mammals or humans specifically using ipamorelin.
Regarding menopause specifically, no studies identified in this series have analysed CJC-1295 or ipamorelin in connection with hormonal changes or menopausal symptoms. This represents a true and complete evidence gap, not an area with even preliminary findings.
CJC-1295 and Ipamorelin and male fertility
Human studies specifically linking growth hormone to male fertility offer slightly more substantial evidence than the female side. However, it is worth noting that these studies concern growth hormone itself, not CJC-1295 or ipamorelin. A noteworthy human clinical trial published in Fertility and Sterility analysed growth hormone treatment in men with subfertility who were identified as having impaired growth hormone response. It found that 12 weeks of growth hormone treatment was associated with a significant increase in sperm motility in these men. Oestradiol, testosterone, prolactin, FSH and LH levels remained unchanged throughout the study period [3]. This is a significant and directly relevant human finding. It is important, however, to be precise about what exactly it establishes, and what it does not establish. It involved direct administration of growth hormone, in a specific population already identified as having reduced growth hormone responsiveness. It did not test a growth hormone secretagogue such as CJC-1295 or ipamorelin. It also did not include men with normal baseline growth hormone levels.
Regarding ipamorelin specifically, its original pharmacological characterisation involved testing in animal models in pigs. This testing indicated that the compound, along with related growth hormone secretagogues tested at the time, did not significantly impact FSH, LH, prolactin or TSH levels. This suggests a degree of hormonal selectivity specifically for the growth hormone pathway, rather than broad interference with other reproductively relevant hormones in this animal model [4].
This is a calming signal at the animal pharmacology level. However, it is not the same as a dedicated study of fertility or sperm quality in humans. No such studies of CJC-1295 or ipamorelin in men have been published.
Limitations of current evidence
The overall picture here is one of relevant, albeit indirect, evidence. There is solid clinical data in humans linking growth hormone itself to sperm motility and the stability of reproductive hormones in specific populations [1], [3]. Animal studies looking at ipamorelin specifically suggest that it may not broadly disrupt other reproductive hormones, at least in one species tested [4]. There is also one fish study showing effects on reproductive cell development [2].
However, none of these add up to direct proof that CJC-1295 or ipamorelin affects human fertility, sperm quality or reproductive hormonal balance in men or women. No dedicated human studies for either peptide for this purpose have been conducted.
Disclaimer
This content is for educational and informational purposes only and should not be interpreted as medical advice, diagnosis, or therapeutic recommendation. CJC-1295 and Ipamorelin remain research compounds and are not approved by the FDA or the European Medicines Agency for any medical use, whether used individually or in combination. No published human study has tested either compound for effects on fertility, sperm quality, or reproductive hormones. Any individual experiencing fertility concerns should consult with a qualified healthcare professional or fertility specialist for evidence-based evaluation and treatment options.
References
[1] Zhou, X.-Y., Ma, J.-N., Shen, Y.-Y., Xie, X.-R., & Ren, W. (2023). Effects of growth hormone on adult human gonads: Action on reproduction and sexual function. International Journal of Endocrinology, 2023, Article 7492696. https://doi.org/10.1155/2023/7492696
[2] Gouda, M., & Ganesh, C. B. (2024). The influence of ghrelin agonist ipamorelin acetate on the hypothalamic-pituitary-testicular axis in a cichlid fish, Mozambican tilapia. Animal Reproduction Science, 268, Article 107550. https://doi.org/10.1016/j.anireprosci.2024.107550
[3] Ovesen, P., Jørgensen, J. O., Ingerslev, J., Ho, K. K., Ørskov, H., & Christiansen, J. S. (1996). Growth hormone treatment of subfertile males. Fertility and Sterility, 66(2), 292–298. https://doi.org/10.1016/S0015-0282(16)58456-8
Raun, K., Hansen, B. S., Johansen, N. L., Thøgersen, H., Madsen, K., Ankersen, M., & Andersen, P. H. (1998). Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology, 139(5), 552–561. https://doi.org/10.1530/eje.0.1390552