Harmalas do not potentiate LSD.

http://www.maps.org/news...ters/v06n3/06332ott.html

"We thus have both experimental and anecdotal evidence that MAOI, far from potentiating LSD, rather seem to exert an effect parallel to that of DMT - blocker, serving also as LSD-blockers!"

Once we had taken 7.5 grams of very potent dried Stropharia. We were interested in making contact
with the 'voice in the head' phenomenon. We potentiated the mushrooms by each smoking about
750 grams (!) of passion flower (reduced as described above) starting about 30 minutes after eating
the mushrooms. The potentiation was quite overwhelming. After smoking about one quarter of the
plant material, each fresh lungful brought on, within seconds, powerful "starburst" and "intersecting
lightning bolt" hallucinations which, with eyes opened, obscured a well-lit room. The voice
phenomenon was loud and clear and very unsettling (the content of the trip has been described in
High Frontiers, Issue 2). Before the trip we had attempted on several occasions to invoke the voice
phenomenon with the same mushrooms at dosages of up to 10 grams, to no avail. But, even more
curiously, effects such as clear instance of MAO inhibition, voices in the head, visions (with both
closed and opened eyes) and finally at the end of the period, clear potentiation of another
psychedelic (LSD) occurred at discrete short intervals over a period of 14 days! We realize that this
sounds unbelievable, however it did happen. It is our opinion that particular long-term effects can
be initiated by large combined doses of tyrptamines and beta-carbolines that cannot be adequately
explained using current models of brain chemistry.

In experiments in which we have predosed ourselves with DMT and then taken another psychedelic
several hour later, we have noted very discernible (MDA) to dramatic (mushrooms or LSD) effects
when the second substance is taken as much as 8 hours after the DMT. Again, this is hard to explain
since the total DMT experience should only last about one hour. However, when we smoked DMT
and after the flash smoked the beta-carboline plant material we were unable to cause any clear DMT
imagery. What did happen was an immediate feeling of depression, almost exactly opposite the
effect on mood of DMT.

Beta-Carbolone Potentiation of LSD
We have also experimented with potentiation of LSD by beta-carboline containing plants.
Generically, the effects follow the same patterns. Subjectively, the dose feels three to four times
more potent than it actually is. The closed eye imagery is greatly enhanced with circular highly
visible bright imagery visible on only 25 [sic] micrograms. On higher doses (150-200 micrograms)
there was a feeling of an ancestral presence (we have never felt an outside presence on LSD alone
in over several hundred acid trips but we have found it quite common when LSD is combined with
another psychedelic).
The closed-eye patterns were "almost visions". That is to say they were clearer than hypnagogic
imagery but not as overwhelming or clear as DMT visions. The visuals were more like clear dream
imagery. The mood elevation was quite astounding. At one point one of us shouted "You couldn't
possibly have a bad trip on this stuff." There were no mood swings and the buoyant elation slowly
receded to baseline over the course of the trip.