Of all of these options none of them are outright safe; any site that allows you to buy testosterone by paying for it on their website you need to run for your life, as to do this you will be giving your credit card information to who knows who. As for gym dealers, this can be a tossup. If you can find a gym dealer who is not a middle man you may have a good source on your hands but understand if he gets into trouble himself he will more than likely sell you out at the first chance he gets if it saves his ass even slightly; most of them are scared and will not hold to any honorable line. Without question, when we buy testosterone on the black market there is no safe bet but there are some good sources out there who keep a low profile, use secure servers and email accounts and who are generally safe for most. In the end, understand, such purchases are illegal in many countries so if you choose this rout the risk is on you and you alone.
Now, how does this lead to shyness or a love of parties? Well, imagine the extravert and the introvert both getting drunk, taking off their clothes, and dancing buck naked on a restaurant table. The next morning, the extravert will ask you what happened (and where are his clothes). When you tell him, he’ll laugh and start making arrangements to have another party. The introvert, on the other hand, will remember every mortifying moment of his humiliation, and may never come out of his room again. (I’m very introverted, and again I can vouch to a lot of this experientially! Perhaps some of you extraverts can tell me if he describes your experiences well, too -- assuming, of course, that you can remember you experiences!)