. >> prescriptions have more than doubled in the last five years and this paish jentz his symptoms were closer to depression. >> disnal. -- dismal he says injections helped him. >> and replace many has documented benefits, some are cautious about future down sides that could develop for patients who may stay on the drug for decades. this doctor prescribes in specific case autos data is that you need to establish is not in yeet research will likely focus on long term cancer risks but given the current demand several companies are already offering new testosterone-based drugs and some have predicted that could triple to $5 billion per year putting testosterone replacement in the financial league of viagra. >> testosterone is kind of an he lismser. it improves quality of life. there is a lot of affects on the body like putting premium fuel in the body. >> there are a lot of men on testosterone for the general health reasons and there is one of the most-rapidding growing fields in medicine. >> the treatments are often covered by insure yoons as we continue tonight michael finney follows up