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.
The analytical strategy is governed by different requirements of hair sample preprocessing and analytical detection. Most of the anabolic steroids are neutral compounds and are thought to be (weakly) incorporated into hair via sweat and extracted best by methanol extraction. A washout of steroids was recurrently observed and hair segmentation is certainly not expedient when dealing with neutral anabolic steroids. However, the basic compounds clenbuterol and stanozolol require an additional sodium hydroxide digestion of the remaining hair fibers to improve their recovery.