WADA's thresholds limit the abuse of HGH. Assuming the sports federation tests for it and would actually process the positive. Finally, most athletes keep their health complications from doping private. It's kind of like asking a heroin user about their drug use. Not too many honest answers.
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The longer answer and why PED testing, as implemented by the IOC permits doping to flourish:
HGH use is popular in many Olympic sports. It requires a blood test, which testing has only recently gone into double-digits of all tests run for 2012(??)
The "decision limit" varies depending on the method used to test the blood samples. 1.81 or 1.68 for males, 1.46 or 1.55 for females. So, as long as the athlete does not cross the threshold, HGH use is okay. How difficult is it to monitor your use? The athlete can run their own tests.
http://www.healthtestingcenters.com/hgh.aspx USD $79! Combine it with a $49 Testosterone test and you'll never test positive for either and get all the benefits.
Here's WADA's official friendly, not-scientific information:
http://www.wada-ama.org/en/resources/q-and-a/human-growth-hormone-hgh/
See WADA's published scientific document on the HGH testing procedure here:
http://www.wada-ama.org/Documents/S...s_hGH Differential Immunoassays_EN_June10.pdf If that link doesn't work, use google and enter the phrase "wada hgh differential immunoassay"