if you are referring to parts coming from Aliexpress, then rest assured 99.99% are fake, the scrap the surface and laser itch the intended part number.
I have tried lots of OPamps and caps from aliexpress, and then tested them, only a few which were USED 2nd hand parts were founfd to be original but again faulty. rest all of them were fake.
You can also check youtube regarding legitimacy of such parts, use an alcolohol dip swap to dissolv the printing or magnetic test.
as far as OPAMPs are concerned, the reliable source is pulling from the old faulty CD Players and other equipment involving audio output.
I ususaly visit the reapir market to get hold of boards having good opamps, or ask the tech to remove them for me.