Estradiol facilitation of cocaine self-administration in female rats requires activation of mGluR5. Erection problems, with possible libido loss. Only the group that had estrogen and functioning mGluR5 signaling exhibited a pronounced increase in cocaine intake see Figure 1. These sexual behaviors are powerful triggers for drug urges and relapse. Unfortunately, they are among those most likely to cause sexual side effects. When stimulant drug use and sex are strongly linked with one another, attempts to stay off the drugs are less likely to be successful if the client continues to engage in sexual behaviors previously associated with the drug use. Studies have further shown that mGluR5 activation causes neurons to release endocannabinoid neurotransmitters anandamide and 2-arachidonoylglycerol that activate CB1R signaling. It's hard to have fast, hard sex but a lot easier to have slow, gentle sex, which can be passionate but it's not heart-pounding, "I feel taken" passionate. Dopamine that is not absorbed into the post-synaptic neuron is broken down and taken back up into the pre-synaptic neuron. Sexual Function Many people think that using cocaine will give them a sexual supercharge as it creates euphoria and a surge in both energy and sensory awareness. For more on this, see my post of May 1, The Effects of Cocaine Short Term Users feel the effects of a single dose of cocaine almost immediately. All in all it's one of the worst things to experience when you're an experienced user. Whereas 60 to 70 percent of methamphetamine users reported drug-induced increases in sex drive, fantasies, pleasure, performance, obsession, and unusual or risky sexual behaviors, 40 to 50 percent of cocaine users reported these effects. Studies have shown that the female hormone estradiol contributes to these differences, but not how. Even a sexual act in which two intoxicated people have agreed to engage in is not considered consensual and can possibly be classified as sexual assault.