Psychedelic Drugs and Dosages

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A wide variety of chemicals and plants have psychedelic (“mind-manifesting”) effects. The most widely used substances are listed here together with dosages adequate for a normal adult of average size. The dosage to be taken depends, of course, on the goal of the session. Two figures are therefore given. The first column indicates a dosage which should be sufficient for an inexperienced person to enter the transcendental worlds described in this manual. The second column gives a smaller dosage figure, which may be used by more experienced persons or by participants in a group session.

LSD-25 (lysergic acid diethylamide) 200-500 ug 100-200 ug
Mescaline 600-800 mg 300-500 mg
Psilocybin 40-60 mg 20-30 mg

The time of onset, when the drugs are taken orally on an empty stomach, is approximately 20-30 minutes for LSD and psilocybin, and one to two hours for mescaline. The duration of the session is usually eight to ten hours for LSD and mescaline, and five to six hours for psilocybin. DMT (dimethyltryptamine), when injected intramuscularly in dosages of 50-60 mg, gives an experience approximately equivalent to 500 ug of LSD, but which lasts only 30 minutes.
Some persons have found it useful to take other drugs before the session. A very anxious person, for example, may take 30 to 40 mg of Librium about one hour earlier, to calm and relax himself. Methedrine has also been used to induce a pleasant, euphoric mood prior to the session. Some times, with excessively nervous persons, it is advisable to stagger the drug-administration: for example, 200 ug of LSD may be taken after the person has become familiar with some of the effects of the psychedelic state.
Nausea may sometimes occur. Usually this is a mental symptom, indicating fear, and should be regarded as such. Sometimes, however, particularly with the use of morning-glory seeds and peyote, the nausea can have a physiological cause. Anti-nauseant drugs such as Marezine, Bonamine, Dramamine or Tigan, maybe be taken beforehand to prevent this.
If a person becomes trapped in a repetitive game-routine during a session, it is sometimes possible to “break the set” by administering 50 mg of DMT, or even 25 mg of Dexedrine or Methedrine. Such additional dosages, of course, should only be given with the person's own knowledge and consent.
Should external emergencies call for it, Thorazine (100-200 mg, i.m.) or other phenothiazinetype tranquilizers will terminate the effects of psychedelic drugs. Antidotes should not be used simply because the voyager or the guide is frightened. Instead, the appropriate sections of the Third Bardo should be read.

pp. 101, 102 The Psychedelic Experience by Timothy Leary, Ph.D., Ralph Metzner, Ph.D., Richard Alpert, Ph. D.