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 products containing IGF-1, other growth factors, and related hormones is banned by the World Anti-Doping Agency and most professional sports organizations. These substances are also on the DoD Prohibited Dietary Supplement Ingredients list, so Service Members should avoid products with these ingredients. Supplemental use of IGF-1 can cause 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 07 March 2022