Injectable steroids are injected into muscle tissue, not into the veins. They are slowly released from the muscles into the rest of the body, and may be detectable for months after last use. Injectable steroids can be oil-based or water-based. Injectable anabolic steroids which are oil-based have longer half-life than water-based steroids. Both steroid types have much longer half-lives than oral anabolic steroids. And this is proving to be a drawback for injectables as they have high probability of being detected in drug screening since their clearance times tend to be longer than orals. Athletes resolve this problem by using injectable testosterone early in the cycle then switch to orals when approaching the end of the cycle and drug testing is imminent.
Test prop works by making the muscles hold onto nitrogen, which means the muscles hold onto more protein. Holding onto proteins means better usage of energy, which subsequently means increase in muscle size and strength. Test prop has the ability to stop muscle wasting so you keep all of the muscle mass you worked hard at getting. There is no muscle wasting from the glucocorticoid hormones and red blood cell production is increased, which subsequently allows more oxygen to come in the body. Higher oxygen level in blood cells mean that you will not tire as fast and as much, what will than aid in recovery times as well.