testosterone stearate testosterone stearate testosterone stearate, also known as testosterone octadecanoate, testosterone 17β-stearate, and androst-4-en-17β-ol-3-one 17β-stearate, is an injected anabolic-androgenic steroid (aas) and an androgen ester – specifically, the c17β stearate (octadecanoate) ester of testosterone – which was never marketed. it is a prodrug of testosterone and, when administered via intramuscular injection, is associated with a long-lasting depot effect and extended duration of action. testosterone stearate may occur naturally in the body. testosterone stearateclinical dataother namestestosterone octadecanoate; testosterone 17β-stearate; androst-4-en-17β-ol-3-one 17β-stearateroutes ofadministrationoral, intramuscular injectionidentifiers iupac name phenanthren-17-yl] octadecanoate pubchem cid57463467chemspider58539759chemical and physical dataformulac37h62o3molar mass554.900 g·mol−13d model (jsmol)interactive image smiles cccccccccccccccccc(=o)o1cc21(cc32ccc4=cc(=o)cc34c)c inchi inchi=1s/c37h62o3/c1-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-35(39)40-34-23-22-32-31-21-20-29-28-30(38)24-26-36(29,2)33(31)25-27-37(32,34)3/h28,31-34h,4-27h2,1-3h3/t31-,32-,33-,34-,36-,37-/m0/s1key:fhjsgesowqsdbh-mxfprffxsa-n it has been said that with longer-chain esters of testosterone like testosterone stearate, the duration of action may be so protracted that the magnitude of effect with typical doses may be too low to be appreciable.