Of greater concern is the fact that milk from rBGH-treated cows has higher levels of IGF-1, a hormone that normally helps some types of cells to grow. Several studies have found that IGF-1 levels at the high end of the normal range may influence the development of certain tumors. Some early studies found a relationship between blood levels of IGF-1 and the development of prostate , breast , colorectal , and other cancers, but later studies have failed to confirm these reports or have found weaker relationships. While there may be a link between IGF-1 blood levels and cancer, the exact nature of this link remains unclear.
Others purchase HGH products -- or products that claim to increase your body's own production of HGH -- in the form of pills and sprays. Companies that market these products on TV infomercials or online claim they turn back your body's biological clock, reducing fat, building muscle, restoring hair growth and color, strengthening the immune system, normalizing blood sugar , increasing energy and improving sex life, sleep quality, vision , and memory. However, the Federal Trade Commission has seen no reliable evidence to support the claim that these products have the same effects as prescription HGH, which is always given by injection. Taken orally, HGH is digested by the stomach before it can be absorbed into the body.