Dream Herb - Calea zacatechichi - was traditionally used by the Chontal Natives of Oaxaca, Mexico. It still is being traditionally used by the Chontal Indians to induce dreams. It would be prepared as a tea and drank while smoking a cigarette made up of the Calea zacatechichi foliage just before going to bed.

Exactly how Dream Herb (Calea zacatechichi) effects the brain is not well understood. The plant contains 0.01% of a crystalline alkaloid, C21H26O8. Modern studies have shown an increase in brain activity during sleep and some minor hallucinations of subjects when awake.

It has been found to increase the superficial stages of sleep and the number of spontaneous awakenings. Those who partook of the Dream Herb were able to experience lucid dreaming; the ability to control and remember their dreams with less effort.

Auditory hallucinations are also fairly common, which prompted the Chontals, believing they were hearing the voice of God, to refer to Calea zacatechici as Leaf of God. A feeling of well-being is said to persist for a day or more with no unpleasant side effects.