"A Guide to Doping's Grey Area"
I suppose I shouldn't be surprised to see thyroid medication on this list. I literally cannot get out of bed without it, after thyroid cancer kayoed my metabolism a few years ago. Back in 2018 a nurse practitioner with my *former* health care system told me to stop taking it. Like a fool I listened. Within a month I was in the ER, practically unable to walk. A friend had to pour me into the ER chair because my legs were like jello. ER doc was baffled why the NP told me discontinue the med and put me back on it immediately. But by then I'd lost any confidence in that health care system and switched (to the VA, which has generally been very good, and offers the option of seeing doctors outside the VA system).
Thyroid meds take awhile to build up enough to feel any effect. Some docs say up to 2-4 weeks. Usually I can feel some difference in a week. Because I also have osteopenia
(Protip: Don't get old. It sucks.) my endocrinologists have been very cautious in my dosages. Too little and I'm a zombie. Too much and there's a risk of bone density loss, and symptoms often associated with bipolar disorder -- too much energy, anxiety, irritability, insomnia, etc.
My docs started me at 25 mcg years ago, barely enough to have any effect with a non-functional thyroid, but potentially enough to give an edge to a healthy person with normal thyroid function. And their lab work would still be within the high normal limit. The docs very gradually increased my dosage to, currently, 125 mcg. At 112.5 mcg (yeah, they really do come in increments that fine) I could still exercise, but I was sluggish and exhausted immediately after a workout, and slept 12 hours a day. My average speed on my usual cycling route declined from 17 mph to 14 mph. My jogging was already slow, but slowed even more from around 10 min/mile to 14', and my distances were declining from 5-7 miles to 2-3 miles. Within a week of being on the slightly higher dosage my average speed was close to normal again and I'm able to resume jogging 5-7 miles at modest speed.
If it'll have that effect on a 60something y/o, it's likely to offer a significant edge to a young and healthy athlete. Especially if their thyroid level is nearer to the low normal than high normal limit.
Although I didn't know that was part of the Floyd Landis cocktail. I have heard about it with some track runners, especially women over age 30 since they often have valid need for it.
And because levothyroxine dosages are measured in micrograms, with the pills all pretty much the same size from 25 mcg on up, there's plenty of room for "Oops, I didn't realize I was taking so much" excuses. Generic levothyroxine comes in tiny pills that are all vaguely different shades of grey. A color blind person, or someone who takes it early in the morning as directed, and leaves the lights off in the kitchen or bathroom, could easily overlook the slight differences between pinkish-grey, orangey-grey, blue-grey and grey-grey. I still have most of my old prescriptions, from 25 mcg up to 125 mcg, and if I forget to stash the old bottles in a separate place I can easily pop the wrong dosage when I'm bleary eyed in the early morning.