Up until 1985 human growth hormone was a human brain derived product. Unfortunately that year it was linked to Creutzfeldt-Jakob Disease (CJD) which is a variant of what is now called mad cow disease. After 1985 synthetic versions of human growth hormone were developed that don't expose the user to CJD, but long-term studies pointed to other risks. Specifically a significant risk of cancer, especially colon cancer and Hodgkin's disease.
- developing irreversible acromegaly (abnormal growth of bones of the hands and feet and face)
- high blood pressure
- heart damage
- premature aging and death
- soft tissue swelling
- thickening of the skin, abnormal hair growth
- colonic polyps
- liver damage and glucose intolerance
- muscle weakness
- enlargement of the internal organs
- arthritis
- impotence