Peganum harmala, which is also known as Syrian rue, is a popular MAO-inhibitor. It's also much cheaper and doesn't make one vomit (although mild feelings of nausea are possible).
0.2 to 0.3 grams of extract contains enough harmine and harmaline to block MAO activity for about six hours.
Peganum harmala contains a high concentration MAO-inhibiting substances. This means it can be very dangerous when combined with certain foods or other psychoactives that are totally harmless when taken by themselves. Avoid foods that contain tyramine and do not combine with SSRI's (prescribed or recreative) and similar medication.