Standardized extract?

[bman1]

How can there be a standardized extract. Swib sees many place selling kratom, salvia, and many other extracts that range in number for standard potency. Swib was wondering how come they do not vary in potency. Example salvia and kratom leaves both vary in potency. So would taking two different batches of leaves at two different potencies not come out with different strength extracts?

[sunyata]

I think they have a standard for how much Salvinorin A should be in one g of Salvia leaf, then they just make sure there's 10 times that in one g of standardized 10X extract. What this standard is or who defined it, I don't know. I suppose they would have to add pure Salvinorin to the Salvia in order to make it truly "standardized".
I don't even know if this is how it's done, but I remember wondering about the same thing and thinking this up.
Can anyone confirm, and maybe give a better description of how it's done?

[Alfa]

There are 2 ways I know of:
1. Salvinorum A is extracted and applied to empty salvia or even another herb. This can be done exact.
2. Multiple batches are mixed. The average content is measured. Salvia divinorum contains more Salvinorum A in the middle of summer heat, then at other times.