In November 1942, the Italian cyclist Fausto Coppi took "seven packets of amphetamine" to beat the world hour record on the track.  In 1960, the Danish rider Knud Enemark Jensen collapsed during the 100 km team time trial at the Olympic Games in Rome and died later in hospital. The autopsy showed he had taken amphetamine and another drug, Ronicol , which dilates the blood vessels. The chairman of the Dutch cycling federation, Piet van Dijk, said of Rome that "dope – whole cartloads – [were] used in such royal quantities." 
Trenbolone also has progestagenic affects. Tren, as we’ve previously said, possesses strong androgenic properties. Tren is not known in the anabolic steroid community to cause gyno. However, it would be interesting to observe many cycles of anabolic steroids which include a heavily aromatizing steroid with trenbolone. No doubt many athletes have combined tren and testosterone with miraculous results. It would be interesting to note amongst these individuals if they have ever developed gyno when combining the drugs, but not when taking them alone. Remember, progesterone sensitizes the body to estrogen, so whatever estrogen is available will be more likely to act out and cause the negative effects we know estrogen is responsible for. The moral of the story is to be cautious and knowledgeable about the drugs you are combining. Actually, that should be true whether you are 21 and raving at a night club on e, or a responsible individual, through with your party stage, and maximizing your safe use of anabolic steroids. Drug synergy can be an amazingly useful tool when used for maximal gain, but can be very unfortunate and even dangerous if multiple negative properties of drugs are allowed to gather inside the body. We will talk more about the specifics of drug synergy in another section.