Preload all chemical data:
ChemicalData[All, "Preload"];
RebuildPacletData[]; (* the latter should not really be necessary *)
Get all names:
cd = ChemicalData[];
Get their molecular formulae:
l = ChemicalData[#, "MolecularFormulaString"] & /@ cd;
By counting the Cs, Os and Hs in the tattooed diagram we know we have to find $\rm{C_{19}H_{28}O_{2}}$. Looking for all molecules that have that molecular formula:
p = Position[l, "C19H28O2"];
Column[Labeled[ChemicalData[#, "StructureDiagram"], #] & /@ Extract[cd, p]]
Looks like it is Testosterone.
