Several studies have been done by different investigators on the effects of Peyote consumption on human chromosomes. One study of the Huichol Indians found no abnormalities, even though the subjects took Peyote an average of 35 times a year all through their adult lives. Another study of the Yanomama Indians of Venezuela found no detectable incidence of chromosomal damage of either sex, despite the fact that only the men partook in Peyote.

A study of Navaho members of the Native American Church who used Peyote regularly, drew some interesting conclusions. The study was based on a sample group of about 30,000 participants in the Peyote ritual. For the purpose of the survey, it was assumed that each participant partook once a month. ( This is a low approximation ) Of an estimated 180,000 ingestions, there were only 5 reported incidences of negative reactions.

This works out to about one bad trip in 70,000. Even though this studies figures are probably somewhat off, it is obvious that the incidence of negative reactions to mescaline are very low. It should be noted that the ingestions took place in a more or less structured and controlled environment. The chances of a bad reaction in stressful settings is probably greater. Anxiety is almost a universal side effect for the inexperienced user. It is not being caused directly by the mescaline, but by your apprehension of taking it.

Possible negative side effects that may be encountered, and frequency of occurrence are:

Anxiety - Very common

Queasiness or upset stomach - Very common

Nausea - Common

Muscle tension (tightening of muscle in neck and face) - Common

Respiratory pressure (hard to breath) - Uncommon

Feeling of lose of control - Common at higher doses ( Ego dissolution )

Feeling of fear - Common with inexperienced users

I have not been able to find any LD-50 information on mescaline and man. However if you are a large Rat, then it is strongly advised not to exceed 370 mg / kg body weight of mescaline. The highest known dose given to a human was 1500 mg .

( LD50 = Dosage that will kill half of a control group that take it ).

WARNING: Certain prescription drugs such as insulin, barbiturates or physostigmine, are known to increase the toxicity of mescaline. It is possible that the presence of hyperinsulinism, in conjunction with a large dose of mescaline could prove fatal. Be very careful mixing insulin and mescaline.

WARNING: Mescaline should not be taken by pregnant women. Several animal studies have reported birth defects, miscarriage, and possibly behavioral problems. Of important note, fetal brain levels of mescaline have been found to be 2 - 4 times higher than the mother. There is a possibility that the use of mescaline during pregnancy could be harmful to the fetus, although no human studies have been done. I might mention that very common substances like alcohol or even caffeine can cause fetal birth defects.

There are conflicting views on whether mescaline is dangerous to use with MAO inhibitors. There have been several reports of the use of a strong, but short lasting and reversible MAOI in conjunction with mescaline. Harmala compounds in significant dosages were used to potentiate mescaline with no apparent side effects. Caution is advised whenever using MAOI's.

Overdoses of mescaline are very rare, but if necessary can be treated effectively in an Emergency Room by the administration of a phenothiazine tranquilizer. This should be a measure of only last resort. Do not try to medicate yourself, people in panic attacks tend to overreact, and try to administer too much.

Bad trips and the feeling that you are dying are not totally unheard of, but just remember that it is all in your mind, and you will come down eventually. There have been NO recorded instances of someone dying because of ingesting mescaline.

There has been widespread rumors that taking hallucinogens could set off schizophrenic attacks in susceptible individuals, this idea has since been generally dismissed. It is important to note that diagnosed schizophrenics are comfortably able to ingest Peyote. This suggests that psychedelics do not in themselves trigger psychotic episodes, but may allow some sort of stress releasing mechanism to emerge.