Any product from GNC that could cause positive test for steroids?

Factual Questions
1

I watch Sportscenter on ESPN every morning before I go to work, and it seems that many times when an athlete has tested positive for anabolic steroids, they blame some supplement that they bought at GNC. I heard this very excuse this morning on Sportscenter from boxer Roy Jones Jr.

The defense they always put forward is along the lines of “I work hard before the competition, I don’t always have the time/means to check if everything I take is on the banned list. Something I took from GNC must have caused me to test positive for steroids.”

Is there any sort of supplement an athlete could purchase at GNC that would actually cause them to test positive for anabolic steroids? I know that you can purchase a goodly number of weight gain products, vitamins, weight loss stuff, etc…but it seems to me that a product that would cause someone to test positive for anabolic steroids would be frowned upon.

I assume many athletes that get caught are simply lying to make themselves look better, but I am pretty curious about this.

2

I seem to remember one instance of unbanned supplements having trace amounts of a banned substance, but AFAIK that was an isolated incident.

The notion that professional athletes are just taking supplements willy-nilly is laughable. These people make money for their athletic performance, so they know exactly what’s going in everything they take.

3

What’s GNC? Is it a store of some kind?

(It makes your posts far more readable if you define your acronyms)

4

GNC is a health food/supplement store that’s pretty well-known.