There is a parallel internet where illegal things and services are sold openly using Bitcoin crypto currency. If you decide to go down this path then anonymity should be your #1 priority. You should take a few days to educate yourself about Tor (the onion router), download and familiarize yourself with Tor browser or even better Tails live operating system. Google "deep web black market" there are youtube videos about it too. Some of the deep web sources might be outdated as some markets get shut down and new ones appear. There is also a search engine called "Grams" which allows the users to search through all of the black markets. You can find the .onion addresses on google or by using the privacy friendly search engine - .
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.