A huge number of (male) athletes across all sports are doping now. Testosterone deficiency is a medical condition, and taking “testosterone replacement therapy” is explicitly allowed by many sports. Even if it’s not allowed, it’s not really possible to robustly test for, because in some forms at least it’s simply increasing the levels of the same hormones that your body is naturally producing. Same goes for human growth hormone. Just take enough to put your levels at a very high, but plausibly natural level and you essentially can’t fail a drug test.

It’s only called “testosterone replacement therapy” when it’s prescribed by a doctor btw. Taking exactly the same course of medication in any other circumstances is called “taking steroids”.

Is trivially Easy to test for TRT. Taking testosterone shuts off your body’s LH and FSH production and those can be tested. These can be biologically mimicked with hCG and HMG but those don’t chemically show up on LH and FSH tests.

LH ratios aren’t a robust test, aren’t accepted by any governing body alone as far as I’m aware, and are only a very weak indicator if you’re only testing urine. Testosterone to epitestosterone ratio is still the gold standard, and to fail that test you need a ratio about 3x above normal. The efficacy of these tests are also highly impacted by when the PEDs were last taken, and that’s true for all classes of PEDs, not just the bio identical ones.

There are also faaaaaar more PEDs than the labs test for. The state of PED testing is completely unreliable, and you really have to be an idiot to get caught. But that’s only if your PEDs are actually prohibited, which they often aren’t.

Which sports is TRT specifically allowed? The only one I know of is MMA, but I'd consider that marginal as a "sport". Are there others?

FIFA call it a “therapeutic use exemption”, which basically anybody can get with a note from a doctor. A lot of other sports have similar exemption processes. I know the NFL does too.

> FIFA call it a “therapeutic use exemption”, which basically anybody can get with a note from a doctor.

In my quick research on this, the TUE process appeared to be quite strict, and definitely not an easy "you just need a note from a doctor" kind of thing. For example, in the NFL, the only example I could find where they'd give a testosterone exemption is if you had testicular cancer and had removal of 1 or both testes, which seems reasonable. I also found examples where both the NFL and FIFA had recently suspended players for testosterone use.

If you have any other examples or sources that counter this info, I'd be very interested to see it.

You can’t find examples because the treatments are part of the players private medical records and are not published. But it is as simple as getting a doctor to say that therapeutic use is required.