Grey Market
A grey market is trade in goods that are genuine or plausibly genuine but sold outside the manufacturer's authorised channel, or under a label exempting them from the rules governing medicines.
Two different things share the name. One is parallel importation: authentic, approved product diverted from the market it was sold into and resold in another, lawful within the European single market under exhaustion of trade mark rights and itself licensed, with the importer required to notify the marketing authorisation holder. The other is the research-labelled trade, where a substance is sold as a laboratory reagent rather than a medicine.
The difference lies in what stands behind them. A licensed parallel import has a regulatory file, a traceable batch, a responsible person and an obligation to participate in recalls and adverse-event reporting. The research-labelled trade substitutes a sentence on a label for all of it. Declaring a vial not for human consumption changes nothing about the molecule inside; it changes the seller's regulatory category, and with it any obligation regarding sterility, endotoxin limits, cold chain or pharmacovigilance.
Grey market is therefore a statement about channel, not chemistry, and the two senses are conflated deliberately by marketing that borrows the respectable one. The consequences of the second sense are specific rather than atmospheric: no route by which a defective batch is recalled, no system into which an adverse event is reported so harms never aggregate into a signal, no accountable party, and no verifiable storage history, which for a lyophilised peptide governs whether it is still what any assay said it was.
The common misreading is that grey means technically irregular but substantially fine, a shade lighter than black. In the parallel-import sense that is roughly true, because a regulator is still watching. In the research-labelled sense the missing pieces are precisely those that make a product a medicine, and a favourable independent test cannot restore them, since it describes one sample at one moment.