For the chemical detectives, this freely available LINK provides...

For the chemical detectives, this freely available LINK provides access to the active ingredient formulations of the TGA approved evolis tonics for men and women.

The August 2016 approved formulations show swertia chirata natural plant extract to be a primary active ingredient at a concentration of 300 micrograms/mL. This is equivalent to 1 gram of extract needed per 33 x 100mL-bottles of tonic. Or, scaling up, 1 kilogram of extract would be sufficient to manufacture 33 thousand bottles of tonic.

This Alibaba LINK shows the existence of multiple suppliers of swertia chirata, in minimum purchase quantities of at least 1 kilogram. One supplier indicates a minimum order of 100 kilograms. Prices vary wildly according to purity and source, but it is obvious that both cost and supply of this extract are not material risk factors for evolis manufacture.

My understanding is that Advangen chemists now first isolate the highly active component that they have identified in the mix of terpenoid-based constituents of natural plant extracts of this form. The use of that purified component then has allowed for a far more flexible active formulation of the evolis products.