"Parabolan is not like sustanon, it only has one long ester attached to it. The chemical compound is Trenobolone Hexahydrobenzylcarbonate. The Hex ester is very similiar to the enanthate and cypionate esters, in fact there is really no noticeable difference in there activity within the human body. The Hex ester has an active life of about 14 days, which is almost identical to that of the enanthate ester. Your best bet nowadays would be to get your hands on some trenbolone enanthate, which is now being produced by a handfull of quality UG labs.
Para should be injected every 3-4 days to keep blood levels stable, just like enanthate. It won't be completely out of your blood stream until about 14 days, but your blood levels will start decreasing slightly after about 5 days. That's why most people use to run Para every 3 days. Supra and Shanghai both are making tren enan right now, there are a few others, but I'm not familiar with them."
both of these paragraphs were copied from a post on AR.