This small, spiny member of the cactus family grows primarily in southern Texas and the northern part of Mexico. Macromerine, a phenethylamine hallucinogen closely related to mescaline with: about one-fifth that drug's gram potency, is its primary psychoactive chemical constituent.

To achieve an effect equal to that of mescaline in intensity, requires about eight to twelve fresh Dona Ana cacti (Coryphantha macromeris). After the spines have been removed, the cacti should be chewed thoroughly before swallowing, or a tea may be brewed by boiling the cacti in water for about an hour and straining. Either way, do it on: an empty stomach because nausea or vomiting may be experienced during the early stages of the trip. Vomiting will not in any way change the effect of the drug, however.

First Dona Ana effects begin coming on within an hour or two, and the whole hallucinogenic, mind-altering experience 'may last up to twelve hours.

If 'the user's head is screwed on reasonably well to begin with, there are no known dangerous aftereffects from this drug. In this respect it is similar to all of the LSD-like substances.

Dona Ana should not be taken in overly large doses, nor should it be combined with MAO inhibitors such as yohim bine, harmala alkaloids, tryptamines, or the drugs Marplan, Catron, Parnate, Eutonyl, Eutron, Nardil, Niamid, and Marsalid.