Yes, it can have pretty explosive side effects...

But it's not on the WADA banned list so you are free to try it.

Caffeine is also an ergogenic and is not banned by WADA, either in or out of competition.

Naturally occurring salts available as commodity food ingredients at every grocery store? Eating is essentially doping? Brushing your teeth is doping?

Wearing corrective lenses improves performance. Is wearing glasses considered doping too?

The list of things not allowed exists: it's official for every sport association that adheres to it. There's authorities, rules and processes for testing them.

So it's not really obscure and doping only matters under those terms. Outside that scope whatever you use is on your conscience alone.

See also danburbridge's reply to GP.