Gotta agree, they saw it was pharma stuff and only a small amount, not even AAS so they just let it through. Probably thought it was your medication, don't quote me but I've heard there's a little known law stating you are allowed to import any medications that you need from another country and they are not allowed to forbid you access to anything that you might need for your health in case you aren't able/can't afford to get it here.
Just looked that up, the fda site says that its illegal to import drugs not approved by the American FDA, but
"FDA, however, has a policy explaining that it typically does not object to personal imports of drugs that FDA has not approved under certain circumstances, including the following situation:
The drug is for use for a serious condition for which effective treatment is not available in the United States;
There is no commercialization or promotion of the drug to U.S. residents;
The drug is considered not to represent an unreasonable risk;
The individual importing the drug verifies in writing that it is for his or her own use, and provides contact information for the doctor providing treatment or shows the product is for the continuation of treatment begun in a foreign country; and
Generally, not more than a 3-month supply of the drug is imported."
Anyway I'm guessing if it were UGL or some Tren etc. then it would've been taken, they couldn't be sure you didn't need it and they're not controlled substances