Start with the source
FDA says a badly made compounded medicine can be dirty, or can hold too much or too little of the ingredient that does the work (the active ingredient).
You cannot measure that at home, which is why the pharmacy’s name on the label and its license matter.
An injection can bypass defenses that normally help block toxins and germs, so contamination can cause serious harm.
A package whose pharmacy name cannot be matched to a license record has failed a basic safety check.
Keep the label, receipt and photos if something seems wrong.