Editor's Note: Ian Kerner is a licensed couples therapist, writer and contributor on the topic of sex for CNN.
(CNN) - In the movie "Annie Hall," the titular character likes to smoke a joint at bedtime because, she says, it relaxes her and helps get her in the mood for sex -- even though her boyfriend claims it cheapens the experience.
Although there's a difference between dependency and enhancement, Annie might have been on to something. Researchers are beginning to study the link between cannabis and sexual desire, with some interesting results. In one recent study, for example, investigators found that men and women who used marijuana daily had about 20% more sex during the previous four weeks than their peers who abstained from the drug.
Although this research didn't show cause and effect, it raises an interesting question: What's the connection between sex and marijuana? I posed this and other questions about sexual desire and pleasure as related to cannabis to some of my colleagues.
Marijuana affects libido in different ways
It's still unclear exactly how marijuana might boost sex drive, but theories abound.
"People who use marijuana may have more sex because they put less pressure on themselves when they are high, so they don't have the same performance anxiety as those who are sober," suggested sex therapist Amanda Pasciucco, who practices in Connecticut, where medical use is legal. "A small amount of marijuana may also help increase your ability to communicate your preferences to your partner."
Sex therapist Lawrence Siegel noted that in particular, delta-9-tetrahydrocannabinol -- the cannabinoid THC -- appears to target a part of our brain associated with sexual arousal, at least in females.
"Our body's natural endocannabinoid system is key in regulating things like pleasure, pain, relaxation and homeostasis. When it is activated by the cannabinoids in cannabis, it can leave users feeling relaxed with increased pleasure and decreased pain," explained Peter Barsoom, founder of a company called 1906, which aims to bring cannabis back to the mainstream. "This can lead to increased arousal and make sex even more enjoyable. For others, the reason is the increased pleasurable sensations that can arise with cannabis. This effect can make sex feel even more enjoyable."
Though some people experience increased anxiety when using marijuana, others find that it has the opposite effect. "Every person has a unique makeup both psychologically and physically, and for cannabis to help improve sexuality, you must find the type that works for you," explained sexologist Nick Karras, author of "The Passionate High: A Guide to Using Cannabis For Better Sex and Creativity." "I recommend experimenting with a small amount of indica strains, sativa strains and a hybrid of both to see what works best."
Delivery and dose matter
Almost all of the experts I spoke with recommended starting out with a small amount of cannabis and using a specific delivery method. "I definitely recommend smoking or vaping as you're learning how to use cannabis, because you can overshoot with edibles and have an uncomfortable experience," Karras said. Because it's more difficult to control the dose of cannabis in edibles, it could lead to a longer-lasting or unpleasant high.
That said, a growing number of edible products contain carefully dosed amounts of cannabis. One such product, High Love, contains a low dose of cannabis, along with certain herbs, in a chocolate base. "Interestingly, the aphrodisiac qualities of cannabis seem to only occur in low to moderate doses," pointed out its creator, Barsoom. "In high doses, cannabis can have an opposite effect."
THC vs. CBD
The cannabis plant contains roughly 100 cannabinoids, which are its active components. The best-known of these is THC, which is believed to be mainly responsible for cannabis' psychotropic effects, including marijuana's high. But another cannabinoid, CBD, doesn't contribute to euphoria and is legal when used recreationally if it's derived from hemp. CBD derived from either hemp or marijuana is legal in 46 states when used medicinally.
Some products aimed at improving your sex life contain CBD but not THC. These are topical creams, ointments or lubricants that capitalize CBD's apparent anti-inflammatory effects.
For example, a line of CBD-based lubricants called Privy Peach is meant to quell inflammation and increase circulation, which may in turn improve sexual function and arousal in women with problems such as endometriosis and other types of chronic pelvic pain, said its inventor, Kimberly Koehler. Another topical CBD product called Foria Awaken is targeted for women who experience pain during intercourse. Because some women find that the THC in marijuana seems to cause vaginal dryness, CBD-based lubes could also be a way to counteract that side effect.
If you're interested in experimenting with cannabis to see how it affects your sex life, there's one more thing to keep in mind. Although recreational marijuana use is now legal in nine states and medicinal use is legal in 29, you may put yourself at risk if you live elsewhere.
"Until the federal government lifts its ban on marijuana, clinicians like myself are in a double bind," sex therapist Israel Helfand said. "Even if it is legal in the state where we practice, we can face legal and ethical issues if we recommend it or use it ourselves."
Of course, cannabis isn't a cure-all, and it can't fix many of the root causes of sexual dysfunction or relationship problems. But if you want to experiment legally to see whether it enhances libido and gives your sex life a boost, you may find that marijuana is one more way to spice things up.
"Cannabis has been used as an aphrodisiac in many cultures for centuries. In India, it was used as far back as the seventh century. Its use for sexual health was documented in Chinese texts, amongst Germanic tribes and by many African cultures," Barsoom said. Maybe it's high time to add the American bedroom to the list.