Here part of the discussion from another forum: So basically at a ph of higher than 4 supposedly (i have no proof of it) fibrils can be formed, but if you lower the ph with AA then the risk of fibrils (again supposedly) goes away, but the reconstituted cagri needs to be used ASAP or it loses effectiveness. I personally ignored such concern as people were all over the place with some claiming that the risk were very low, so I've been just constituting with BAC and using it within about 10 days. But I was wondering anyway if such claims were valid or not...
Fibrils are of secondary importance in this discussion. You could almost leave them out of it.
The real toxic species are oligomers. Oligomers eventually become fibrils, but they raise a lot of hell on the way.
And yes, they subjected many different amylin analogues to mechanical stress to see which ones fibrillate. Fibrils are a lot easier to detect than oligomers.
Two important points about those tests:
1. Almost every single amylin analogue fibrillated at pH 7.5 (including cagrilintide). The only one that didn't was rejected for low potency.
2. Many of the amylin analogues did *not* fibrillate at pH 4.0 (not just cagrilintide).