A large amount of research has been performed in man and animals regarding the immediate effect of marihuana on bodily processes. No conclusive evidence exists of any physical damage, disturbances of bodily processes or proven human fatalities attributable solely to even very high doses of marihuana. Recently, animal studies demonstrated a relatively large margin of safety between the psychoactive dose and the physical and behavioral toxic and lethal dose. Such studies seemed to indicate that safe human study could be undertaken over a wide dose range.

Low to moderate doses of the drug produce minimal measurable transient changes in body functions. Generally, pulse rate increases, recumbent blood pressure increases slightly, and upright blood pressure decreases. The eyes redden, tear secretion is decreased, the pupils become slightly smaller, the fluid pressure within the eye lessens and one study reports that the eyeball rapidly oscillates (nystagmus).

A minimal decrement in maximum muscle strength, the presence of a fine hand tremor, and a decrease in hand and body steadiness have also been noted. Decreased sensitivity to pain and overestimation of elapsed time may occur.

The effects of marihuana on brain waves are still unclear and inconsistent. Generally, the intoxication produces minimal, transient changes of rapid onset and short duration. Sleep time appears to increase, as does dreaming.

Investigation of the effects of marihuana on a wide variety of other bodily function indices has revealed few consistently observed changes.

These few consistently observed transient effects on bodily function seem to suggest that marihuana is a rather unexciting compound of negligible immediate toxicity at the doses usually consumed in this country. The substance is predominantly a psychoactive drug. The feelings and state of consciousness described by the intoxicated seem to be far more interesting than the objective state noted by an observer.