The use of pro-hormones came into public awareness in 1998 with the athletic successes of Mark McGwire. A pro-hormone is a precursor to a hormone and the human body converts it into an anabolic hormone, or muscle growth stimulant, that acts effectively like a steroid. Because pro-hormones share common side effects such as hormone disturbance, endocrine system impairment, acne, hair loss, liver damage, development of effeminate characteristics, growth stunting, elevated cholesterol and blood pressure, kidney impairment and male infertility, the Food and Drug Administration banned all pro-hormone supplements.
"Tren" or Finabolan
Finabolan is a muscle strength and hardening pro-hormone anabolic with powerful androgenic, or masculine trait, properties. People typically use the drug during the cutting and hardening phases of muscle building. The most disturbing side effects of this compound, caused by the overstimulation of testosterone hormone production, are aggressiveness, restlessness, sleeplessness, mood swings and unwanted weight gain. Many users experience a "testosterone rush," which is uncomfortable and alarming.
"Havoc" or Thioderon
This pro-hormone, developed by the Japanese, is an anabolic/anti-oestrogenic, c-17 alpha alkylated steroid. Even though "Havoc" displays milder androgenic properties than some other pro-hormones, the most concerning side effects are liver toxicity, increase in HDL/LDL cholesterol levels and increased risk of cardiovascular problems. It reportedly causes fewer problems with hair thinning and may actually decrease oestrogen levels.
"Spawn" or Trenabol and Epistane
"Spawn," another anabolic supplement, is actually the combination of two powerful pro-hormones, trenabol and epistane. It is also metabolised by the liver and because it has such toxic properties, it could only be taken for four weeks, a relatively short time in the process of bodybuilding. The most concerning side effect of "Spawn" is the impairment of the endocrine system, which can cause havoc in the body.