Most of this is for my benefit rather than for yours.
Here is what you or I should do if we believe someone is doping: Report Doping in Sport.
Here is what athletes mustn’t take or do: WADA 2014 Prohibited List.
Here is how athletes can conveniently check whether something they are considering taking is on that list or not: Global Drug Reference Online. Conveniently this accepts brand names. You also get a “Reference Number” as part of the results – you should write this down as evidence of your diligence before taking anything which is allowed. Also record the serial or batch number from the packaging in case you do all that you can and later find out that the product was contaminated.