Carbon Isotope Ratio and Testosterone

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Kirf

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I’m an endurance athlet trying to understand doping tests better – hope for your inputs and assistance in clarifying detection times.

The traditional method of detecting abuse of testosterone looks for an imbalance in the ratio of testosterone and epitestosterone. It is referred to as the T/E ratio test. A normal ratio for most humans is near 1:1. The World Anti-Doping Agency (WADA) considers a ratio over 4:1 to be a positive test. But testosterone/epitestosterone ratios return to normal quickly, even overnight if taken in the right doses, why one can use small amounts of testosterone for doping, i.e. improved performance and recovery.

But there is a test that can detect even though that bespoke T/E ratio has returned to normal and that is the Carbon Isotope Ratio (CIR). Labs determine the quantities of carbon-12 and carbon-13, two isotopes, or types, of carbon, within an individual’s testosterone molecules. Synthetic testosterone has less carbon-13 than naturally occurring testosterone. Synthetic testosterone has less carbon-13 than naturally occurring testosterone.


Until very recently, the procedure from WADA has been to 1) test for the T/E ration and if, and only if, above 4:1, then 2) use the Carbon Isotope Ratio. This leaves a window of opportunity for using testosterone up to the level of, let’s say, 3,999:1. And that is indeed performance enhancing for an endurance athlet.

The cyclist Tom Danielson was busted by CIR (Carbon Isotope Ratio), but appently the CIR test was used as a step 1, i.e. without Tom Danielson being the above the 4:1 ratio. USADA determined that the ratio between carbon-12 and carbon-13 isotopes in Danielson’s testosterone molecules did not match the ratio that occurred naturally in the rest of his body. A synthetic form of the hormone had to be present. How it got there will be the crux of Danielson’s defense, but its presence is undisputed thanks to CIR.
Please look into the article here: http://velonews.competitor.com/2015/08/news/the-test-that-caught-tom-danielson_381086

My question to all you wise people: for how long time can the Carbon Isotope Ratio test detect endogenous testosterone, let’s say a product like Andriol testo-caps?
 
I'm pretty sure drug test questions are again blua. Also as long as synthetic test is present in the body it should be detectable. Look at a chart or detection times and half lives. Or just don't use test
 
Serotonin101: Do you have a chart or something about detection times for CIR, then please post link.
Thanks.
 
I have done some more research on this and it seems like no clear "conclusion".


This, however, is interesting in relation to food influence on testing: Compounds from C3 plants (eg, wheat, barley, oats, sugar beet, rye, cotton) generally have carbon isotopic values in the −35‰ to −22‰ range whereas compounds from C4 plants (eg, corn, millet, sugar cane, sorghum) exhibit δ13C values ranging from −8‰ to −20‰.14 In agreement with the data published recently,15 the mean δ13C values measured for androsterone were −19.0‰, −20.5‰ and −22.0‰ for SAF, JAP and ITA, respectively.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2784500/


This one below is also quite comprehensive and it confirms the non-effective current T/E test, for example: The administration of oral preparations results in increased values that can be detected, however for less than 24 h even when taken daily for 21 days, while daily or intermittent usage of a testosterone-containing gel (100 mg per day) did not systematically alter the T/E values in a way that would be revealed by the GC/MS analysis as exceeding the population-based reference range
http://www.researchgate.net/profile..._in_Sports/links/0fcfd509bd1d184e3b000000.pdf




I also came across this one from WADA, which seems to "confirm" that the use of CIR is only applied to confirm the result of test 1, i.e. T/E value: https://wada-main-prod.s3.amazonaws...c-steroids-measurement-and-reporting-en_0.pdf
However, this is not in line with the "Tom Danielson" example, if one can trust the article....
 
You've come to the wrong forum sorry mate. Not only are questions regarding drug testing (particularly aiding avoidance) against the rules on Bluelight, but IMO this is even worse than wanting to cheat an employment drug test. Sorry, but I guess my moral compass is kicking in.
 
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