non-flash navigation


Biomonitored effects of charas extract


Carl C. Pfeiffer, PhD, M.D., Henry B.Murphree, M.D., and Tod H. Mikuriya, M.D.


On June 15, 1967 at the Bureau of Research in Neurology and Psychiatry c/o New Jersey Neuro-Psychiatric Institute, Princeton, Humphrey Osmond MRCS, LRCP, DPM, Director


We have observed that an alcoholic tincture of cannabis indica (charas) which was confiscated by the U.S. Navy Shore Patrol in Casablanca in 1942 and which has been used annually to demonstrate the marihuana effect in dogs, has an intense euphorient-psychotic effect when given orally to normal volunteer subjects.The peak of symptoms with a threshold dose of 0.25 ml (29 mg) occurs at 1 – 2 hours after dosing. The effect is maintained  for about an hour and is then followed by an overpowering sleepiness which lasts longer than the stimulant-euphoric period. These effects simulate most closely the drug responses reported by smokers of marihuana. The observed effectiveness of the drug by the oral route of administration will facilitate quantification of the response since smoking is a comparatively less accurate method of dosing the human subject.


The charas tincture contains 116 mg of solids per ml so that the effective oral dose of this preparation in man, namely 0.25 ml is equivalent to 29 mg total. Isbell (1) in his study of (-)delta –9 trans tetrahydrocannabinol (9TTHC) found the effective dose to range from 10 to 40 mg. This tincture would therefore appear to be in the range of potency of one of the known active natural principles.


The stimulation is similar to LSD-25 intoxication in that the subjects show euphoria, flight of ideas, obtundation of abstract thoughts, hyper-reflexia, and rise in blood pressure. The effect differs from LSD-25 in that papillary dilation is absent, conjunctival redness is present and intense, geometric visual fluorescent colors are absent and auditory changes are prominent. The LSD-25 effect lasts 6 – 8 hours and is usually followed by insomnia while the charas duration is less than half as long and is followed by a condition of narcoleptic-like sleep.


One of the authors a healthy 32 year old male 72” #195 ingested a double dose of charas tincture 500 mg on a cookie.


Supine BP, Orthostatic BP, Pulse was observed hourly. Phlebotomy was hourly as were the completion of questionnaires. 


Supine BP's were normotensive but orthostatic BP's exhibited increasing hypotension with hour #6 90/50 mm Hg°. Even with the smallest doses, the Clyde Mood Scales confirm the clinical observation of a definite biphasic ephorient-somnolence change. The quantitative EEG is a useful monitor of the cannabis effect in that one sees hyperregulation of  the occipital alpha and a rise in the total mean energy content of the EEG.

Subjective Observations: Experience 500 mg Charas Extract.

            The effects of the substance took effect at about 9:30 AM after taking the aromatic, pungent stuff on a cookie about 9:05 AM. I noted a sense of detachment but a mood of lightheartedness. My ability to focus my thoughts seemed to lose its edge. A rush of ideational fluency overtook me on a possible scientific project that, alas, is lost to  me as the ideas came faster than my ability to speak of them. My sense of consciousness was split: I felt that these flights of fancy were expressions of excellence, yet realized they were probably just flights of fancy caused by the charas.

My psychomotor functioning, despite the cerebral gymnastics busily bemusing me, were indeed quite intact. My ability to walk around the laboratory was unimpaired. I carried my tape recorder outside, sat down neath a tree and recorded my impressions. Later, at the smiling requests of the lab assistants, encouraged by my somewhat fluid volubility ask that I walk a straight line down the hall. I accomplished this without difficulty.

 Perhaps the most interesting lead is the rise in serum uric acid which occurs at the height of the euphoric stimulation. This falls promptly with the onset of drowsiness. This finding may be the first clue to a possible biochemical mode of action of an hallucinogen since we have found that a high uric acid level is presumptive evidence for a rapid dissipation of the adenosine family of high energy phosphate compounds. The conjunctival redness is similar to that which occurs after intravenous heroin injection and therefore may indicate the release of histamine. 

June 15, 1967


Post Scripts

At the time I wondered how Doctor Pfeiffer was able to keep supplies of these drugs that were quite illegal. In his office. In 1985 Acid Dreams by Martin Lee and Bruce Shlain Carl Pfeiffer, PhD, M.D. was identified as a long time contractor to the CIA. Indeed, as a semi witting research subject I was accorded a protected opportunity to experience the effects of oral cannabis. It explained how he got the confiscated charas extract from the navy during WWII.. The findings have never been pursued (as far as I am aware).

The N.J. Bureau of Research  closed many years ago.

Although the paper was an part of an unsuccessful proposal, the property of rapid dissipation of the adenosine family of high energy phosphate compounds implies possible application of cannabis as an antidote to neurotoxic poisons.


THM  7-30-02 Berkeley, California