Drugs injected IM, intradermally or (rarely IV) as oil-based formulations or oil/lipid depots, particularly sexual/anabolic steroids. To quote Meyer & Mann 2015 (PMID PMID 25686650), *well described in on-line chat rooms related to the use of anabolic steroids in body building". Synthol as used by bodybuilders exposes to similar risks (PMID 19580174)