The other side of this coin is:

Supplements containing DRUGS which are not listed on the label.

Foods containing things that shouldn't be there unless proven effective.

This is not the same as the Euro issues with limiting doses, or content.

But then, who am I to say... what doors this opens?

Supplements would be free to buy as long as they conform to safety labeling.
Do you know how many erectile supplements actually contain Viagra?
This has been a real problem in US. People taking this can die under certain complex drug interaction scenarios.

Many imported supplements from China contain many toxic drugs, that are removed from sale here... like chloramphenicol (antibiotic), and
phenylbutazone (anti-inflammatory).

It is something to think about. Abuses of the system often result in overly restrictive laws as a result. So there is no one clear cut answer to this problem of adulterated or misbranded supplements.