10ml vial contains 100mg/ml Testosterone Propionate
This is an esterified form of the base steroid testosterone, much like enanthate, cypionate and Sustanon 250. It’s a superlipophillic, oil-based injectable that slows the release of the steroid into the blood stream. But compared to enanthate and cypionate, propionate is a very short ester and is still released quite fast. As such more frequent injections are needed. Levels will peak after 24-36 hours and begin tapering from there on out, making the longest possible time-span between injections, at least or proper results, about 3 days. Most athletes will opt to inject 50-100 mg every day to every other day.
What is to note with propionate, is that users have successfully incorporated it into cutting cycles as well. Especially people who tend to lose a lot of mass normally during extreme diet phases find this useful. By injecting every two or three days and using only 50-75 mg each time, no notable water builds up (or at least none that can’t be fixed with Proviron, Arimidex or Winstrol) and no fat is deposited, thus allowing a user to stay relatively lean. So this type of testosterone can be used to keep gaining or retaining mass until 2-3 weeks out of contest time with relatively little difficulty. Although most will choose to add Proviron (50-100 mg/day) out of precaution. Its best use is of course still in bulking phases to pack on mass. Testosterone is not the king of the hill of all mass-builders for nothing.