I have been able to find yohimbine extract 8 percent and believe it can be found at up to 20 percent. Yohimbine is an indole alkaloid.
The trunk bark of yohimbe contains up to 6% indole alkaloids, mostly of the yohimbane class, including yohimbine, a-yohimbine, d-yohimbine, allo-yohimbine, coryantheine, etc. – plus various isomers and heteroyohimbanes. The best-researched alkaloid is yohimbine (17 a-hydroxy-yohimban-16a-carboxylic acid methyl ester), the leading pharmaceutical drug for impotence.
Yohimbine.HCl [Y1002]
Description: alpha2-adrenoceptor blocker.
Chemical Formula: C21H26N2O3.HCl
Molecular Weight: M.W. 390.9
Solubility: Soluble in Water (10 mg/ml).
CAS Number: CAS [65-19-0]
Handling: Store in Tightly Sealed Vial.
Storage: Room Temperature.
Trying to find usable indole sources, I do not claim to be a chemist by any means so forgive me if this indole has no use.
Not a chemist I just follow directions on the box mix