Hi Maldorf, Mass Spec is good to ID the molecular weight. If the mass spec can give the molecular weight to enough decimal points, it means you can be certain of the compound's ID. Although IR can quickly ID functional groups, it is less helpful for the type of certainty one can achieve by Mass Spec and is harder to interpret for novices (FTIR is generally used in labs to determine of a functional group transformation has been effected. For instance, if a chemist tried to convert a carboxylic acid to an ester, an FTIR could quickly confirm that). I'd recommend GC-MS against an internal standard, HPLC-MS, or even HPLC-UV against a calibration curve of the standard. I think sending it off to test is the best/cheapest way.
A home test won't tell you the dosage. For folks wanting to do a home test, just know that it should be considered as a more rudimentary test that answers the question, "Is this likely an anabolic compound or not?"