and Sexual Function
effects of cannabis
Use of cannabis
commonly causes a sense of euphoria, relaxation, enhanced
appreciation of sensory stimuli (food, music, sex), and
increased sociability. Physical effects include increased
heart rate (tachycardia), lowered blood pressure, and
injected conjunctiva (red-eyes). Na"ve users are
more likely to report adverse psychological effects such
as anxiety or paranoia from a single dose. In considering
the potential effects of cannabis on an individual, the
experience of the user must be taken into account, due
to the effects of tolerance and learned behaviour. A dose
of cannabis which could cause intense intoxication in
a na"ve user may have little or no effect in a regular
cannabis user. On the other hand, the effects of cannabis
can be quite subtle, and na"ve users may not experience
an effect until they have learned to appreciate it, or
how to inhale the drug effectively, a situation known
as "reverse tolerance"
have investigated the effects of drugs on sexual behaviour
in laboratory animals, either as the main purpose of a
study or as variables in studies addressing other matters.
Fonseca et al noted changes in density of cannabinoid
receptors in the rat hypothalamus over the oestrus cycle,
with lower densities during the fertile period and suggested
"possible sex steroid-dependent differences
in the sensitivity of certain neuronal processes to cannabinoid
treatment." Navarro et al reported "acute
THC markedly altered the behavioral pattern executed by
the animals in a socio-sexual approach behavior test...
presumably indicating loss of sexual motivation",
however Shrenker et al found neonatal THC exposure to
increase adult sexual responses in mice, although the
same team had earlier found THC to suppress male copulatory
behaviour in rats, Uyeno reported changes in male rat
sexual dominance behaviour, and Cutler et al reported
cannabis to decrease sexual behaviour in mice.
In a study
of hashish and mating behaviour in mice, Frischknechtet
al found chronically-treated animals showed decreased
sexual behaviour, and concluded "whereas
tolerance to the sedative effects of hashish developed
very rapidly, the drug influences on social behavior were
stable". In hamsters, Turley et al found THC
to stimulate female sexual receptivity behaviour (lordosis,
ultrasound verbalisations). Sieber et al studying male
mice, reported "sexual behavior was
even more frequent in drugged animals than in controls",
although they had earlier reported "sexual
and aggressive behavior was not significantly affected
by the drug". Dalterio et al found in-vitro
THC to depress testosterone secretion from mouse testis.
Frischknecht et al found hashish extract to abolish or
reduce submissive behaviour by mice introduced to a previously
dominant agressive animal.
Rozenkranz et al reported cannabis and THC to reduce secretion
of female sex hormones (FSH,LH,Prolactin), and Smith et
al counselled "it is not known how much disruption of reproductive hormone levels is
necessary for changes in human fertility and sexual function
Due to restrictions
on the availability of cannabis preparations for research
purposes, there are few human studies of cannabis and
sexual function in the scientific literature.
In a critical
review of the effects of marijuana on sexual function,
Abel stated "Marihuana usage is associated with a life-style that involves earlier
and more frequent sexual activity." but commented
"there is no evidence that human marihuana
users... are less fertile", and criticised
the rigour of animal studies "in virtually
every study conducted with animals, there has been a basic
confounding between direct drug action and secondary effects
resulting from drug-induced decreases in food and water
consumption and attendant weight loss."
al found low dose, high dose and placebo subjects not
to differ significantly in subjective ratings of sexual
content of a series of test cards. Mattes et al reported
a dose-dependent reduced salivary flow in human volunteers,
but no direct effect on taste function. Whether cannabis
may affect vaginal secretions is unclear.
In recent IDMU
surveys, several respondents have listed "sex"
or enhancement of sexual/sensual pleasure, as a reason
for using cannabis, a positive benefit arising from cannabis
use, or as their best drug experience. Quotes included
"feel bliss out buzz erotic love play" and "it
seems to grow my ears, eyes and heart/brain". A previous
survey of 600 cannabis users in 1984 found no difference
in levels of cannabis use between singles, couples, separated
or gay respondents, although separated respondents did
report a greater number of drug-related problems.
use was widely-perceived as an attribute of the permissive
lifestyle in the 1960s, there appears nothing in the drug
itself which would primarily stimulate sexual behaviour.
With some exceptions, most animal studies suggest THC
to depress the frequency of sexual activity. A number
of users report improved sexual experience, attributed
to the "pleasurable" perceptual changes of tactile
stimuli rendering the experience more enjoyable, however
there does not appear to be any difference in the frequency
or willingness of individuals to undertake sexual activity,
nor any tendency to greater promiscuity attributable to
the drug effects, rather than the rebellious social attitudes
characterised both by drug use and "free love"
in the 1960s. In the 1990s, drug use is no longer considered
a deviant activity by large segments of the population,
and among young adults experimentation with illicit drugs
appear now to be the rule rather than the exception.