balance late 13c., "apparatus for weighing," from . balance (12c.) "balance, scales for weighing," also in the figurative sense; from . bilancia, from . bilanx (acc. bilancem), from L. (libra) bilanx "(scale) having two pans," possibly from L. bis "twice" + lanx "dish, plate, scale of a balance." The accounting sense is from 1580s; the meaning "general harmony between parts" is from 1732; sense of "physical equipoise" is from 1660s. The verb is attested from 1570s. Balance of power in the geopolitical sense is from 1701; balanced meal, diet, etc. is from 1908.
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.