Half of what people describe as tolerance is a change in the underlying condition, and the two need different answers.

You have two changes at once here. You cannot attribute anything until one of them moves.

A plausible mechanism is not an outcome, and this class is the textbook example.

Cold storage, light protection, date on the vial. Boring, removes half the variables.

Imprint databases are mostly US-centric. A confident hit for another market is still a guess.