Sure, you might be given a "batch number" that matches up with what they said was tested, but that's putting a whole lot of trust in the seller.
Or you test a vial from your own kit. Expensive but still cheaper than compounded GLP-1.
Or you roll the dice and assume that everything ahipped out about the same time with the same cap color is the same batch.
Or you buy from nexaph.
Everyone has to decide their own comfort zone.
Sure, you might be given a "batch number" that matches up with what they said was tested, but that's putting a whole lot of trust in the seller.