so i had been vaguely aware of cats claw since many south american people will label there premade aya as cats claw extract for shipping, presumably since the thick liquid is indiscernible to the customs inspector and cats claw is not implied for anything of potentially questionable legality. recently i learned that it is connected in another way, that is has active maoi, learning this i wondered why it was not a more common replacement for vine. has anyone here used cats claw or know a specific reason why it is not used more in this way?

Cat's claw is a weak MAO-b inhibitor due to its catechin content. I have used it in inhibitor mixes for activating phenethylamine a substrate of MAO-B. Some people do not find it to be effective for this purpose on its own and it's definitely more effective in combination with other MAO-B inhibiting herbs.

Cat's claw doesn't inhibit MAO-A, so it won't work to activate DMT. Although it is used as an admixture plant in ayahuasca brews by some South American tribes and it might potentiate a standard brew slightly by it MAO-B inhibiting properties.

Cat's claw is psychoactive on its own though. It contains rhynchophylline, a tetracyclic oxindole alkaloid that is an NMDA antagonist. On its own and in high enough doses, this herb has mild sedative, calming, and dissociative effects. It can also affect vision and some people find it mildly psychedelic. So this herb would add synergy to ayahuasca brews by its psychoactive properties as well.

There are two chemotypes of this herb. One containing mostly tetracyclic oxindole alkaloids and one with mostly pentacyclic oxindole alkaloids. For psychoactive purposes, the tetracyclic oxindole alkaloid chemotype is best as it contains rhynchophylline.

Another interesting thing is that rhynchophylline actually contains DMT within its structure.