Many people tend to imagine their best sex happening late at night in a dark and romantic environment. But there are some scientific reasons morning sex might be better than night sex—at least for some people. Here's what the experts say.

"You might just have an easier time getting aroused in the morning than you do at night, thanks to your hormones," AASECT-certified sex therapist Jessa Zimmerman, M.A., tells mbg.

For men and people with penises, testosterone levels replenish overnight and thus tend to be at their highest in the morning and at their lowest at night. "Their hormonal pattern follows the circadian rhythm," Alisa Vitti, hormone expert, founder of The FLO Living Hormone Center, and author of In the Flo, tells mbg. "While they sleep, they make all of their testosterone for the next day, and they have the highest blood serum concentration of that hormone upon waking, in addition to the boost of cortisol they get. The combination is very motivating for activities of the physical nature, whether that be sex or a workout."

Testosterone plays a key role in sexual functioning, helping with both getting erections and feeling motivated to have sex. As such, Zimmerman says the elevated testosterone levels in the morning can thus give people with penises an increased libido, improved arousal, and a better erection.

Similarly, estrogen is associated with female sexual desire2, and those hormones also tend to be higher in the morning, according to Zimmerman. Furthermore, morning wood isn't just for penises—people with vulvas also experience increases in blood flow to the vagina during REM sleep3, as well as vaginal swelling and lubrication.

That means they may be as likely to wake up with their bodies already primed for sex. And more blood flow to the clitoris and lubrication around the vagina can mean more sensitivity and pleasure.

Women and people with menstrual cycles don't follow the circadian rhythm, Vitti points out—their bodies and hormonal patterns follow a roughly monthly infradian rhythm, aka their menstrual cycle. This infradian rhythm "impacts their sex drive, their resting cortisol levels, and mood—all of which play a role in sexual readiness and interest," she explains. That means time of day matters less for them—it's more about what time of month it is.

People with menstrual cycles will be more interested in sex in the first half of their cycle (the follicular and ovulatory phases), Vitti explains, when resting levels of cortisol and metabolism are lower (offering more stable mood) and levels of estrogen and testosterone are increasing (boosting sexual desire). During this time, "you'll be interested in this any time of the day, as this hormonal pattern is consistent for many days and is not on a 24-hour timer," Vitti points out. "It will really just depend on when you feel relaxed and unburdened enough of your mental to-do list to get in your body to enjoy the experience."

In the second half of the cycle (the luteal and menstrual phases), the body has higher resting levels of cortisol and decreasing levels of estrogen and testosterone, according to Vitti. This can increase anxiety and lower sexual desire.

"However, you also have the introduction of progesterone, which is a very relaxing hormone, and so if you are hormonally balanced (aka no PMS) this can be a phase of time when sex and experiencing foreplay is extra pleasurable," she explains. "Finally, due to the increase in volume of the uterus during the menstrual week, the internal pressure on your genital organs can make you interested in sex and for it to be very pleasurable."

Another reason morning sex can potentially be better than sex at night? Energy. You're right at the start of your day and at the start of your energy tank, meaning you might be more alert and able to engage in sex.

"The benefit of having sex in the morning is that it might be easier to be present and focus on what's happening in the moment," AASECT-certified sex therapist Lauren Fogel Mersy, PsyD, tells mbg. "When we're tired, we might be more easily distracted."

Many people get to the end of the day feeling exhausted and perhaps touched out, meaning they're not wanting any more touch or stimulation. It may take more effort to get back into the right mindset to engage in sex. "Many people leave sex to the end of the day when they have nothing left in the tank," Zimmerman notes. "That exhaustion and fatigue can lead to neglect and avoidance in your sex life. Having sex in the morning allows you to tap into a fresh fuel tank."

Fogel Mersy also notes that end-of-day sex may be less conducive to creativity, compared to morning sex: "Having a bit more energy or feeling more rested might also lead to trying different things together versus maybe falling into habits or routine when we feel more tired."

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There are also many other reasons some people might prefer to have sex at night instead of having sex in the morning. Mornings can feel like a hectic time for many people, when your mind gets flooded thinking about all the things that need to get done that day and when there tends to be a lot of rushing to get out the door.

Stress can make it harder to get aroused4, so if your mornings tend to be stressful, they may not be the best time to be trying to squeeze in a romp in the sack.

Evenings, on the other hand, may be when you've completed all your tasks for the day and feel more able to relax, which might make it easier to enjoy sex.

Some people may also be more self-conscious having sex in the morning because there's more light, less makeup, and potentially bad breath and body odors. Poor body image can actually hurt sexual functioning5, including making it harder to get aroused, get wet, and have orgasms.

So if you tend to get really in your head about how your partner perceives you during sex, and having sex in the morning exacerbates that, morning sex may not necessarily be as beneficial.

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The best time of day to have sex will vary from person to person and from couple to couple. While elevated hormones might make sex better in the morning for many (particularly men), people with menstrual cycles are much more influenced by time of month than time of day. Moreover, psychological factors like stress and self-consciousness can also come into play and offset some of the benefits of morning sex.

Morning sex is definitely worth exploring if it suits you—the boost of chemicals like oxytocin and dopamine released during sex can help you start your day feeling good, and it can help if you're looking for an extra kick in your erections. But otherwise, you're not missing too much if you prefer to bonk it out after the sun goes back down.