The claim that Omnadren has a duration effect of "a good 2-3 weeks" is somewhat misleading since the half life of the longest lived component is only about 5 days. There is of course some effect 2 or 3 weeks after injection, but relatively little.

The hexanoate ester is quite similar to the well known enanthate ester, but is shorter by one carbon.

The isohexanoate ester in Omnadren is the same, only named differently, as the isocaproate ester in Sustanon. Thus, the hexanoate vs. decanoate difference is the only difference in the mixture of esters.