It depends... im only familiar with those ads that advertise the prohormones supplements.
However, it sounds like you are talking about actual clinic that specialize in trt (test replacement therapy). IF this is the case make sure you research them thorougly.
I use Dr John (aka Swale) over at www.allthingsmale.com and i am quite satasifed. He even is knowledgable enough to help you out during cycles with ancilliarlies and anti-estrogens.