Lot of good variety of caapi out there (whole & ground), even liquid & dry extracts.
When googling caapi extracts, noticed as well there are lab-tested standardized ones now out there with good reviews. Not many dry extracts out there (most are in liquid form). The lab-tested ones had tested for equal amounts of tetrahydroharmine to harmine, they have a very long history of indigenous use.
Found this interesting from Erowid, lot of great studies by Callaway.
TPQ Category UDV members showed greater: As opposed to:
Harm Avoidance:
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Confidence vs Fear of uncertainty
Gregariousness vs Shyness with strangers
Uninhibited optimism vs Anticipatory worry
Vigor vs Fatigability and asthenia
Novelty Seeking:
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Stoic rigidity vs Exploratory excitability
Regimentation vs Disorderliness
Reflection vs Impulsiveness
source: McKenna & Grob 1994 (See full details in Grob et al. 1996)