How does steroid testing actually work?by Dan Lependorf
August 30, 2012
With steroid testing back in the news, I can completely understand if a lot of the details seem overwhelming. It's such a fiery topic, prone to quick reactions based on little fact, that I find that it’s really useful to understand what actually happens in the testing process.
After androstenedione was found in Mark McGwire’s locker during his record-breaking 1998 home run chase, Major League Baseball felt the need to start testing for steroid use. In 2002, MLB started testing for performance enhancing drugs for the first time, and in 2004, test administration was moved into the care of the World Anti-Doping Agency (WADA), an international multi-sport organization dedicated to stopping the rise of performance enhancing drugs. Major League Baseball has a Joint Drug Prevention and Treatment Program, governed by the Joint Drug Agreement (JDA), which outlines the specific rules agreed to by MLB and the Player’s Association regarding substance abuse in baseball. Collection of test samples is carried out by Comprehensive Drug Testing, Inc. (CDT), who then ships the samples to the WADA laboratory in Montreal, Canada, for testing. That last part was crucial in the Ryan Braun fiasco, as CDT didn’t get Braun’s sample to Montreal for two whole days, breaking strict rules regarding chain of custody.
MLB has an exhaustive list of every banned substance, which includes every substance classified in Schedules I or II under the Controlled Substances Act, a federal US law. MLB also bans 70 performance enhancing steroids, hormones, and masking agents, as well as 56 stimulants, such as amphetamines.
Every player on an MLB 40-man roster is tested at least twice per year for performance enhancing drugs or stimulants. On the first day of spring training, every player has to submit a urine sample. After that, CDT will collect a total of 1,400 additional random unannounced urine samples throughout the season. The Joint Drug Agreement also allows for more than 200 urine sample collections on unannounced random dates in the offseason.
There are extra tests for previous violators of the JDA, but there’s also a clause that says if the league or the Player’s Association has evidence to suspect steroid use, they can submit a notification of “reasonable cause”, at which point the player has to submit a test sample within 48 hours.
Melky Cabrera and Bartolo Colon were nailed for the presence of exogenous (non-natural) testosterone in their urine samples. The WADA laboratory in Montreal performs two tests for testosterone, but to explain why, I’m going to have to dip into biochemistry.
The body produces testosterone and epitestosterone, two very chemically-similar hormones, in roughly equal quantities. In healthy adult males, the ratio of the two hormones in the body tends to sit somewhere around 1:1. The relevant difference between the two is that while testosterone has the usual litany of performance enhancing benefits, epitestosterone doesn't. So as you might expect, urine samples of athletes who have taken illicit testosterone supplements (or steroids that are metabolized into testosterone, like McGwire’s androstenedione) often show large amounts of testosterone with relatively normal amounts of epitestosterone.
The first urine test that WADA will perform is a testosterone/epitestosterone ratio screening test, where a urine sample is chemically analyzed to find the ratio of the concentrations of the two hormones. WADA sets the test limit at 4:1. If an athlete’s urine sample contains four times as much testosterone as epitestosterone, the sample is marked as a failed test. Failed steroid tests carry an enormous public stigma, so it’s important to note that somewhere around 5 percent of the population of adult male professional athletes have a natural T/E ratio of 4:1 or greater. Since CDT collects a urine sample from everybody during spring training as well as 1,400 samples over the course of a season, this means that even if steroid use was completely eradicated from organized baseball, more than a hundred urine samples would fail the T/E test every year. This does not mean the player was taking any banned substances. WADA uses the T/E test simply as a culling process, not as a damning confirmation of steroid use.
If a player fails the T/E test, WADA moves onto what they call the confirmation test, an isotope ratio test. I’m going to have to make one more detour into biochemistry here, but I’ll try to keep it quick.
All carbon on the planet exists as a mixture of isotopes, different versions of carbon. Almost all of the carbon on the planet has six protons and six neutrons inside of the atom, which we call carbon-12. However, one percent of the carbon on Earth has an extra neutron, seven in total. We call this carbon-13, and it’s ever so slightly heavier than your usual garden-variety carbon-12. All organic molecules have a significant quantity of carbon, so naturally, the carbon in your body will have a small amount of carbon-13 mixed in. For the most part, carbon-13 walks and talks just like carbon-12, but due to its relative heaviness, plants have been very, very slowly preferring carbon-12 over carbon-13 over several million years. Because of this tiny selection process, the carbon in living things is slightly higher in carbon-12 content than the rest of the carbon in non-living things.
The testosterone naturally produced by the body is made from material that was once a carbon-12 selecting plant (which was eaten by a cow which turned into your steak, for example), so it has a similar isotopic carbon-13/carbon-12 ratio. Testosterone produced outside the body comes from the world of pharmaceuticals, where the carbon hasn't been through the same million-year-old selecting cycle. Because of this, synthetic testosterone tends to be slightly richer in carbon-13 than natural testosterone. WADA uses an isotope ratio mass spectrometer to check the isotopic ratio of testosterone in a urine sample. If it deviates from natural testosterone by three carbon-13 atoms per thousand or more, it’s marked as a failed test, which indicates the presence of exogenous testosterone.
It’s this isotope ratio confirmation test that Cabrera and Colon failed. And unlike a simple T/E test, an isotope ratio test is essentially impossible to fake. But what about Ryan Braun? His T/E test was a reported 20:1, and his isotope ratio test also reportedly came back positive for exogenous testosterone. He won his appeal due to a chain of custody breach, and received a full acquittal. Officially, Braun hasn’t failed a test, so the mandatory three extra tests over the next calendar year won’t kick in. But that positive test is more than enough reason for the league to submit a notification of reasonable cause, and it’s a virtual certainty that Braun’s been tested as frequently as allowable. For the sake of baseball, no news is great news.
References and Resources
- MLB's Joint Drug Agreement can be found in pdf form here.
- WADA's testosterone test procedure is here, if you wanted to know the gory details.
- A great article from 2006 on the Floyd Landis cycling steroid case is here. It also has a (deprecated) link to a published study on the testosterone/epitestosterone ratio. The link is dead, but a nice graph showing the distribution of the T/E ratio among healthy male athletes is still up.
Dan can be contacted here (email) or here (twitter). He welcomes all comments, even offers for cheap male enhancement pills and winnings from lotteries he didn't realize he had entered. (He really wishes you wouldn't, though.)