Apparently nexa/baba/ezp lowered purity guarantee to 98% for everything other than glp1s, guess they got tired of having to keep replacing all that substandard product they’ve been sending out.
They have temporarily lowered the guarantee to 98% because they are having to use a new API. The API guarantees 99% but they don't know without testing a batch. Once the API has been confirmed as high quality I'm sure the guaranty will go back to 99%. There have been problems with API's in China recently, hence the need to switch.
GLP1 peptides are HIGHLY profitable therefore the API used for them is still the same.