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MAOIs - Encyclopedia

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What is a MAOI?

In detail

'Smart' combinations

The danger of MAOIs


List of dangerous combinations

Links / References

What is a MAOI?

Normally DMT - as found in plants such as Mimosa hostilis, Psychotria viridis and Phalaris Arundinacea - is not effective when ingested orally. This is because it is broken down (inhibited) by Monoamine oxydase (MAO). MAO is an important enzyme that breaks down certain chemical compounds such as drugs and poisons.

MAOIs or MAO-inhibitors interfere with the action of the MAO enzyme and stop the breakdown of chemical compounds such as DMT, making it effective when ingested orally. The combination of a DMT containing plant and an MAOI is commonly known as ayahuasca (or yage).

MAOIs must be used with great caution because otherwise they cause harmless food to become poisonous. The results can be dangerous: headaches, nausea, even unconsciousness and death. In shamanistic tradition MAOIs are only used after at least one day of fasting. It is advised to follow this tradition.

So, MAOIs are:

  • Syrian rue (Peganum harmala)
  • Banisteriopsis caapi
  • Passionflower
  • Yohimbe
  • and certain anti-depressiva.

In detail

Monoamine oxidase (MAO) is the primary inactivation pathway of most tryptamines. That's why inhibitors of the MAO enzyme (MAOIs) can be used to potentiate the effects of tryptamines and to make DMT and 5-MeO-DMT orally active.

MAO inhibitors fall into two classes: irreversible and reversible MAOIs. In addition they can inhibit either or both of the two types of the MAO enzyme, MAO-A and MAO-B which are associated with serotonergic and dopaminergic neurons respectively.

Irreversible MAOIs (e.g. the hydrazides iproniazid and phenelzine) bind permanently to the enzyme and cause MAO inhibition lasting 1-2 weeks after ingestion. They are used clinically to treat depression.

Reversible MAOIs, such as moclobemide, which is used as an antidepressant, and the beta-carbolines harmine and harmaline, are effective for much shorter time, maybe up to 24 hours. Recreational drug users around the world are using mainly harmine and harmaline despite the lack of scientific studies on their effects on humans.

'Smart' combinations

Taking MAOIs on purpose doesn't have to come with too much unpleasant side-effects. Nausea is minimized in 'pharmahuasca', which consists of pure DMT and a reversible MAO-inhibitor such as harmine or moclobemide. When the DMT is in a plant extract taking it with a pure MAO inhibiting substance instead of a plant containing MAOIs usually reduces nausea and other body load significantly. MAOIs have also been used to potentiate the effects of mushrooms containing psilocybin and even phenethylamines -- the latter combination can be very dangerous. DPT ingested with MAOIs has been called 'propylhuasca'; DPT is orally active by itself and its dosage should be smaller when potentiated by MAOIs.

According to anecdotal reports one gram (corresponding to approx. 30 mg of harmine/harmaline) of P. harmala seeds ingested inhibits MAO enough to make DMT orally active, while 75 mg of moclobemide is sufficient for the same purpose. In short, this is why DMT containing seeds are combined with peganum harmala to enhance their hallucinogenic qualities.

The danger of MAOIs

There are significant dangers in using MAO inhibitors. Most MAOIs potentiate the cardiovascular effects of tyramine and other monoamines found in foods. Ingestion of aged cheese, beer, wine, pickled herring, chicken liver, yeast, large amounts of coffee, citrus fruits, canned figs, broad beans, chocolate or cream while MAO is inhibited can cause a hypertensive crisis including a dangerous rise in blood pressure.

MAOIs interact with other psychoactive substances in addition to tryptamines; effects of amphetamines, general anaesthetics, sedatives, anti-histamines, alcohol, potent analgesics and anticholinergic and antidepressant agents are prolonged and intensified.

Overdosage of MAOIs by themselves is also possible with effects including hyperreflexia and convulsions.
It should be noted, however, that these strict warnings apply best in the case of irreversible MAOIs, and many users of reversible MAOIs to activate or potentiate tryptamines are not quite as careful with no apparent ill effects.


Tryptamine derivatives and beta-Carbolines have been detected as endogenous metabolites in mammals, including humans. Methyl transferases that catalyze the synthesis of tryptamines, including DMT, 5-MeO-DMT and bufotenine, are found in human lung, brain, cerebrospinal fluid, liver and heart (McKenna & Towers 1984). In the pineal gland MAO is the primary inactivation pathway of serotonin, a neurotransmitter synthesized from the amino acid tryptophan. If MAO is blocked by harmine, harmaline or other MAO inhibitors serotonin can be converted by the methyltransferase enzymes HIOMT and INMT into psychedelic tryptamines (serotonin --(HIOMT)--> 5-MeO-trypt. --(2*INMT)--> 5-MeO-DMT).

So, ingesting l-tryptophan to increase serotonin levels, a candy bar to increase the amount of tryptophan getting to your brain and natural plant material containing 25-50 mg harmine/harmaline to block MAO, all at the same time, might cause your pineal gland to synthesize substantial amounts of 5-MeO-DMT (Most 1986). Similar results might be obtained by substituting 5-hydroxytryptophan (5-HTP) for tryptophan. Normal sleep-inducing doses of melatonin have also been taken with reversible MAOIs with the resulting psychoactive effects suggesting significant interaction of the two substances. This is extremely dangerous for persons with existing amine imbalance or schizophrenia. For normal, healthy people possible consequences are bad.

A potent inhibitor of INMT, which is a necessary enzyme for the synthesis of DMT and 5-MeO-DMT, is found in particularly high concentrations in the pineal gland. A bypassing or inhibition of the synthesis of this inhibitor might be responsible for trances and other psychedelic states achieved "without drugs" (Strassman 1990). See Strassman's article for more info and speculation about the pineal gland.

List of dangerous combinations

Wait at least 3 weeks after taking a selective serotonine reuptake inhibitors (SSRI) before starting with a MAOI. This includes antidepressants such as the herb kanna (Sceletium tortuosum) and pills such as paroxetine (Seroxat), citalopram (Cipramil), fluvoxamine (Fevarin) and sertraline (Zoloft). It's recommended to wait 6 weeks after fluoxetine (Prozac).

Below is a list of substances, that you should NOT take 12 hours before and 12 hours after taking a MAO-inhibitor.

Very dangerous:

  • sleeping-pills
  • anaesthetics
  • migraine medicines
  • allergy medicines
  • over the counter cold medicines
  • cocaine
  • amphetamines (speed)
  • MDMA (XTC)
  • mescaline cacti (peyote and san pedro)
  • alcohol
  • ephedra/ephedrine (for example in products such as Ephedra Super caps, Super stacker, Ultra Boost)
  • pseudoephedrine
  • macromerine
  • phentermine.

Can cause headaches or sickness:

  • cultured dairy products (buttermilk, yogurt, and sour cream)
  • all aged/mature cheese (exception: cottage cheese, cream cheese)
  • dry and fermented sausage (bologna, salami, pepperoni, corned beef, and liver)
  • all meat, fish and eggs which are not fresh
  • pickled herring and salted dried fish
  • meat extracts
  • yeast extracts/brewer's yeast (Marmite)
  • sauerkraut
  • fruits (bananas, avocados, canned figs, raisins, red plums, pine-apple, raspberries)
  • nuts (peanuts)
  • broad beans and pods (lima, fava beans, lentils, snow peas, and soy beans)
  • soyasauce
  • LSA (morning glory and baby hawaiian woodrose seeds)
  • MDA related herbs (nutmeg, sweet flag)
  • chocolate
  • caffeine (coffee, tea, cola, guarana, energy drinks)
  • ginseng
  • St Johns wort
  • nasal sprays (Vicks Sinex, Prevalin or Otrivin)
  • other MAO inhibitors.

Links / References

This article is based on the following pages:

Erowids MAOI Vault

Azarius on MAO-inhibitors

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