Actually it's what the FDA views as INTENT which is typically based on a reasonable person standard.
So these companies are OPENLY selling vials upon vials of PEPs to folk who are obviously not even remotely involved in research, in part bc as you mentioned, forum members are openly discussing where, how, which company and WHY said PEPS were obtained.
It's the DECEPTIVE business practice that irks the FDA bc at least some of these PEPS are approved as supplements although very few are approved for parenteral administration. Those PEPS that are approved for parenteral human use are generally considered DRUGS which require an RX and a good example of the latter include GH secretagogues.
Well as one might could imagine, bc proteins are so HEAT LABILE and prone to denaturing once they confront that stomach PH of 2, they are not the least bit effective if orally ingested.
So what's a PEP company to do? Sell these products in the legal gray zone by implying they are FDA approved as oral sups yet not mention the lack of such approval for their parenteral counterparts to consumers.
Not to fret since we are not talking about controlled substances or even "drugs" per say what the FDA usually want's in circumstances of this nature is for the involved companies to cease selling these products. One exception would be if several "users" developed and documented an infection "caused" by the use of said PEP's ! If such was the case the FDA is well known to punish the involved company as a WARNING for the remaining manufacturers!
Regardless in an effort to save their ass the manufacturers WILL cease PEP sales to appease those little FDA bureaucrats ONLY to move their "plant" overseas where the FDA's ability to manipulate PEP production is much more limited.