When it comes to hormonal contraception, two somewhat conflicting things are true. This type of medication allows millions of people with uteruses to safely plan their families, treat acne, and manage painful hormonal health conditions (and maintain autonomy over their reproductive futures). Yet at the same time, many folks are not always enthused by the side effects that often come with hormonal birth control—side effects that are rarely given the attention they deserve by medical research.

This is incredibly true when it comes to how birth control impacts sleep. Peruse social media and you’ll find lots of videos from folks talking about how they struggled with insomnia after starting the Pill or another type of birth control. Yet other people swear that the same medication helps them pass out like a baby every night. What gives?

The short answer: We’re not sure. Even the experts wish there were more definitive answers available as to how birth control affects our sleep. “The data regarding birth control and sleep is varied,” says Stephanie Hack, MD, a board-certified obstetrician and gynecologist and the founder of Lady Parts Doctor. “While there are studies that suggest sleep quality/efficiency is improved or worsened, there are others that suggest no change at all.”

With that being said, years working with patients—and a deep understanding of hormones—has given hormonal health experts firsthand intel on how birth control might impact a person’s sleep.

The sleep x hormones connection

According to Dr. Hack, the inconsistent way hormonal birth control affects sleep from person to person is partly due to added factors that complicate the picture. “Many different things can affect your sleep, such as medical conditions, mental health, your environment, technology use [i.e. blue light], substance use, your diet, and more,” she says. “It’s difficult to control all of these things when trying to determine if birth control is the culprit for reduced sleep efficiency [or] quality.”

This is likely why past research on the topic has had such mixed results. For example, a 2020 study published in the Journal of Sleep Research concluded that hormonal birth control may interfere with sleep quality/quantity and may be associated with insomnia. But that contradicted the results of an older 2012 study published in the International Journal of Gynecology & Obstetrics, which found that birth control could actually improve sleep efficiency. Cue the confusion.

“[Sex] hormones play a crucial role in regulating sleep patterns, and any changes in their levels can have an impact on sleep quality and quantity,” —Jasmine Pedroso, MD MPH, FACOG, an OB/GYN at Kindbody.

But what do your sex hormones have to do with sleep at all? Turns out that estrogen and progesterone, which regulate your menstrual cycle, also help control your body’s thermostat—and thus play a big role in your sleep, says Aimee Eyvazzadeh, MD, MPH, a California-based reproductive endocrinologist.

In the simplest terms possible: Your body lowers its core temperature before it’s time to go to sleep. This helps prepare you for sleep and ensures you get the most restful sleep possible; it’s a normal part of your circadian rhythm. And both estrogen and progesterone play a role in this process. “Estrogen decreases the body temperature, while progesterone increases body temperature,” Dr. Eyvazzadeh says.

Progesterone has other unique influences on your sleep aside from temperature regulation, adds Dr. Eyvazzadeh. “Progesterone also has a natural calming and sedative effect,” she says. “Imbalances in these hormones can cause changes to the sleep cycle.” Low levels of progesterone has been linked with trouble sleeping.

Can birth control cause insomnia or mess up your sleep?

For some people, adding hormonal contraception (whether that’s combination birth control pills, an intrauterine device, aka IUD, or a progestin-only pill) to the mix may impact their sleep patterns.

“[Sex] hormones play a crucial role in regulating sleep patterns, and any changes in their levels can have an impact on sleep quality and quantity,” says Jasmine Pedroso, MD MPH, FACOG, an OB/GYN at Kindbody. “With hormonal birth control [like the Pill], the introduction of synthetic hormones can create fluctuations in estrogen and progesterone levels. These changes may affect your body’s natural sleep-wake cycle and potentially lead to disruptions in your sleep patterns.” In short, the new hormone levels might make you have trouble falling asleep or staying asleep. (Hello, insomnia!)

Dr. Pedroso says the extent of these effects can vary among individuals. While one person may experience a drastic change to their sleep schedule, another person might not even notice a difference. According to Alisa Vitti, HHC, founder of FLO Living, this could potentially be due to where your hormones were at pre-pill.

“Some women who have low levels of progesterone due to hormonal imbalances before going on a progestin-containing pill could find sleep improvement, potentially due to an increased daily dose of progestin,” Vitti says. “Those whose levels of progesterone are lowered after going on the pill from a normal level before starting the medication could experience the insomnia common from progesterone insufficiency, as their daily dose would be decreased.”

Some of the variable effects on sleep might have to do with the type of contraception as well. “The [Minipill] contains only progesterone, which can have sedative effects and promote drowsiness,” says Dr. Pedroso as an example. (By comparison, combination birth control pills have both estrogen and progesterone.) “However, [progestin-only birth control pills] may also cause fragmented sleep with more awakenings during the night.” Then there’s the hormonal IUD, which she says releases a small amount of progesterone directly into the uterus. “While systemic absorption is very low, some individuals may still experience changes in sleep patterns similar to progesterone-only pills,” she says.

If you take a birth control pill (regardless of whether it has both progesterone and estrogen or just the former), the timing of your dose might also impact your sleep cycle. Birth control pills reach their highest concentration in the blood within one to two hours of taking them, says Dr. Hack. Each pill then lasts around 24 hours. “The best time to take them depends on two factors: when you will remember to take them, and how/if you feel your sleep is being affected,” she says. If you feel like your pill is negatively impacting your sleep, try taking it in the morning. That way, “the peak concentration [of hormones] is reached while you are awake,” she says. If you feel like your birth control is helping your sleep, continue taking the pill at night.

How to get your sleep back on track

Of course, there are also other factors that have nothing to do with birth control that make people with uteruses more prone to sleep problems, too.“Women and people with uteruses are twice as likely to be diagnosed with depression than their male/non-uterus-having counterparts,” Dr. Hack says. “Many mental health conditions are linked to poor sleep, such as depression, anxiety, and psychological stress.”

There’s also sleep apnea—a sleep disorder where a person’s breathing starts and stops throughout the night—which “leads to poor sleep and fatigue throughout the day,” Dr. Hack adds. Anyone can get sleep apnea, but the symptoms are different for people with uteruses and don’t always involve snoring (think anxiety, depression, morning headaches, waking up often during sleep).

Our bodies are unique—including how they respond to medication. That’s why Dr. Pedroso says it’s important to keep track of the changes you notice and communicate any concerns with your trusted health-care provider. That way, you’ll receive “personalized guidance in finding the right balance between contraception and maintaining healthy sleep patterns.”

In the meantime, taking steps to support healthy sleep is a win for everyone—and there are plenty of expert-approved ways to get started. Dr. Hack is a big believer in “creating a bedroom environment that supports healthy sleep and a bedtime routine that sends your body signals that it’s the right time and place to fall asleep.” She recommends limiting your use of screens (and exposure to blue light) at night, as well as avoiding caffeine or eating late at night—all of which can disrupt your sleep.

Dr. Pedroso also says mastering stress management techniques are key to a better night’s sleep. “Manage stress through relaxation techniques, mindfulness, or activities that help you unwind before bed,” she says. With these tips up your sleeve, you’ll be sleeping like a baby in no time.