Looking at past threads on this topic I still can't find any concrete answer regarding the legal situation of harmala alkaloids. The main irritant standing in the way seems to be that retched Psychoactive Substance Act of 2016.

The Acts seems to allow for the possession of tobacco, coffee and I'm assuming items like passionflower sold OTC at numerous pharmacies and health stores. All these things contain harmala alkaloids maybe not in as high amounts as plants like rue but still present nonetheless.

Would this make harmala alkaloids exempt from scrutiny under British law enforcement?