Insulin-like growth factor type 1—commonly known as IGF-1—is a hormone produced naturally, mostly in the liver, and is involved in the human body’s growth and development. IGF-1 also is found in colostrum—the milk produced by humans and other mammals (including pigs and cows) the first few days after giving birth. IGF-1 levels in humans normally rise from birth until late puberty and then begin to decrease.

IGF-1 also can be made in a laboratory, but synthetic IGF-1 is a drug and is not permitted for use as a dietary supplement. So, like other prescription drugs, it cannot be obtained or used legally without a prescription.

Use of IGF-1 products is banned by the United States Anti-Doping Agency, World Anti-Doping Agency, and most professional sports organizations. IGF-1 is also on the OPSS list of DoD-prohibited substances, so Military Service Members should avoid products with this ingredient. IGF-1 falls within the class of “peptide hormones,” and supplemental use can have serious side effects.

Oral sprays, lozenges, and other products with IGF-1 are promoted as dietary supplements, and sometimes IGF-1 is represented as “deer velvet extract” (see the OPSS article on deer velvet). However, not all dietary supplements with “IGF” in their name actually contain IGF-1, so it’s important to read labels carefully.

Updated 3 June 2019

References

Dobolyi, A., & Lékó, A. H. (2019). The insulin-like growth factor-1 system in the adult mammalian brain and its implications in central maternal adaptation. Frontiers in Neuroendocrinology, 52, 181–194. doi:10.1016/j.yfrne.2018.12.002

Guha, N., Nevitt, S. P., Francis, M., Woodland, J. A., Böhning, D., Sönksen, P. H., & Holt, R. I. G. (2015). The effects of recombinant human insulin-like growth factor-i/insulin-like growth factor binding protein-3 administration on body composition and physical fitness in recreational athletes. Journal of Clinical Endocrinology & Metabolism, 100(8), 3126–3131. doi:10.1210/jc.2015-1996

Hoeflich, A., & Meyer, Z. (2017). Functional analysis of the IGF-system in milk. Best Practice & Research Clinical Endocrinology & Metabolism, 31(4), 409–418. doi:10.1016/j.beem.2017.10.002

Munblit, D., Treneva, M., Peroni, D., Colicino, S., Chow, L., Dissanayeke, S., . . . Warner, J. (2017). Immune components in human milk are associated with early infant immunological health outcomes: A prospective three-country analysis. Nutrients, 9(6), Art. E532. doi:10.3390/nu9060532

Rosenbloom, A. L. (2009). Mecasermin (recombinant human insulin-like growth factor I). Advances in Therapy, 26(1), 40–54. doi:10.1007/s12325-008-0136-5

Tan, L., Wei, T., Yuan, A., He, J., Liu, J., Xu, D., & Yang, Q. (2017). Dietary supplementation of astragalus polysaccharides enhanced immune components and growth factors EGF and IGF-1 in sow colostrum. Journal of Immunology Research, 2017, 1–6. doi:10.1155/2017/9253208

U.S. Anti-Doping Agency. (2014). IGF-1 and the World Anti-Doping Agency Prohibited List. Retrieved 28 May 2019 from https://www.usada.org/igf-1-and-the-world-anti-doping-agency-prohibited-list/

U.S. Food & Drug Administration. (2014). Full prescribing information: Increlex. Retrieved 28 May 2019 from https://www.accessdata.fda.gov/drugsatfda_docs/label/2014/021839s016lbl.pdf

U.S. Food & Drug Administration. (2017). Report on the Food and Drug Administration’s review of the safety of recombinant bovine somatotropin. Retrieved 28 May 2019 from https://www.fda.gov/animal-veterinary/product-safety-information/report-food-and-drug-administrations-review-safety-recombinant-bovine-somatotropin#IGF-I