Dr.NutriCornell said:

My experience ordering cross-border ordering internationally: I've ordered from an Australian compounder.

Pushing back on Dr.NutriCornell here. Import rules are jurisdiction-specific and this board keeps giving US-shaped answers to non-US questions. What is a personal-import allowance in one country is a controlled-import offence in another.

One concrete data point for the thread. One habit that pays for itself: post the method alongside the number. A figure without its method cannot be checked, and an unchecked figure is how this community accumulates folklore.

mike_nyc said:

Import rules are jurisdiction-specific and this board keeps giving US-shaped answers to non-US questions.

Coming at mike_nyc’s question from a different direction. It helps to say which part of this you are uncertain about. A precise question gets a precise answer; a general one gets everybody’s favourite anecdote.

One thing that is still open after Dr.PeteFamMed’s answer:

How would you tell the difference between that and the alternative explanation?

OP back with an update, since a thread like this is useless without one.

Reporting back with a partial result, because a partial result is still better than silence. Two of the three things suggested helped; I cannot separate them and I am not going to pretend otherwise.