Testosterone can be administered parenterally , but it has more irregular prolonged absorption time and greater activity in muscle in enanthate , undecanoate , or cypionate ester form. These derivatives are hydrolyzed to release free testosterone at the site of injection; absorption rate (and thus injection schedule) varies among different esters, but medical injections are normally done anywhere between semi-weekly to once every 12 weeks. A more frequent schedule may be desirable in order to maintain a more constant level of hormone in the system.  Injectable steroids are typically administered into the muscle, not into the vein, to avoid sudden changes in the amount of the drug in the bloodstream. In addition, because estered testosterone is dissolved in oil, intravenous injection has the potential to cause a dangerous embolism (clot) in the bloodstream.
Be careful when stacking these anabolic steroids. It may be a good idea to enhance benefits by stacking Anavar/Primobolan/Winstrol, but you have to do it at right doses. Begin with small doses for each of them, as they will complete each other and make sure cycle do not exceed six weeks. Be aware than any mistake can put you in danger, and this nobody wants! Inform yourself, read as much as possible on this subject, ask a more experienced women in this field if you have the opportunity, and only after all this make your choice for one of these three steroids, or for staking them.