Can You Change Your Circadian Rhythm?

Are you unhappy being an early bird or a night owl, or do you need to change your sleep schedule for some reason? Read on to learn if it’s possible.

By Sheryl Grassie

Jan 27th, 2021

If you take on a new job, travel frequently, or are just looking to shift your sleep-wake time by a few hours, you may be wondering if you can actually change your circadian rhythm.

This internal body clock runs on a 24-hour cycle for humans, effectively keeping us awake during the daylight hours and asleep at nighttime. As we age, our circadian rhythms naturally change anyways, so making a shift in your sleep cycle is possible and safe as long as you still are getting a total of 7-9 hours of sleep each day.

Keep reading to learn more about the circadian rhythm, how it shifts, and how you can change your circadian rhythm.

What is a Circadian Rhythm?

All living creatures, from humans down to the smallest microorganisms have an internal biological clock that controls numerous biochemical processes during a 24 hour cycle. This clock operates and manages our sleep and waking cycles called our circadian rhythms. In humans, this internal clock is located in a part of the brain called the hypothalamus. Within this part of the brain, there are a group of neurons called the suprachiasmatic nucleus (SCN), where the clock gets regulated.

Our circadian rhythm is essentially our internal clock for a day. The term circadian comes from the Latin, circa meaning about, and diem meaning day, meaning “in the course of a day.” It determines how much sleep we need, when we fall asleep, and when we wake up. This pattern can change, and does change, over time. There are both internal and external factors that affect our circadian rhythms.

Can You Change Your Circadian Rhythm?

Changing your circadian rhythm is entirely possible. Essentially, you’re wondering if you can change the times you are asleep and awake. Many people do this; for example, shift workers. Though it’s not ideal to shift your sleep-wake cycles from the normal human circadian rhythm of sleeping during the night and staying awake during the day.

Your circadian rhythm naturally changes as you age, causing many of the sleep problems older people face. If you’re trying to change your circadian rhythm for any reason, whether it’s to have more time in the morning or evening, or to take on a new shift of work, keep in mind that you should still be getting the total amount of necessary sleep to stay well rested and healthy.

How Does Your Circadian Rhythm Change Over Time?

Due to decreasing hormones, our circadian rhythm naturally gets earlier as we age. The older you get, the earlier you go to bed and the earlier you wake up, generally speaking. In addition, since hormones contribute greatly to the timing of when you sleep and wake, adolescence ushers a change in the other direction. Hormones during puberty cause sleep schedules to be pushed way back, making it hard for teenagers to make early morning practices or get to bed at a reasonable hour.

Internal Factors That Affect the Circadian Rhythm

In addition to your circadian rhythm changing naturally over time with the rise and fall of hormones, there are additional internal factors that affect it. To start with, genetics play a role. The amount you sleep, and your pattern of sleep, are to some degree inherited. “We are a family of night owls,” has a genetic basis. Further, internal conditions like pain, side effects from medications, and stress can all affect the sleep/awake cycle.

External Factors That Affect the Circadian Rhythm

The way we live in the world has a profound effect on sleep and circadian rhythm. Travel, changing schedules, light exposure, meal timing, and temperature all affect the way our biological clock regulates sleep. Of these, perhaps light is the most important.

If we are exposed to light in the morning, it shuts down the production of sleep hormones and encourages an earlier bedtime. If we are exposed to the blue light of screens (TV, computer, phone) in the evenings, it limits the release of sleep hormones and keeps us up late.

How to Change Your Circadian Rhythm

Changing your circadian rhythm can be done in a very intentional way. If for example, you want to start getting up earlier and going to bed earlier, you might change your light exposure to better suit this rhythm. Or, you might set your alarm for 15 minutes earlier, and go to bed 15 minutes earlier, and increase this slowly over time until you reach your desired schedule.

When we travel to another time zone, our bodies will naturally adjust our circadian rhythms, but it takes time. This is a clue that we can change the rhythm, but slowly works best. Our bodies like consistency, so be gentle when making changes.

Here is a list of things you can do to reset your circadian rhythm:

  • Pay attention to light. Get early daylight exposure. Stay off screens in the evening. Sleep in a dark room.
  • Don’t nap. This confuses the issue when you are trying to reset.
  • Slowly adjust your bedtime and wake time.
  • Don’t eat for several hours before bed. Change your mealtime to fit with the desired sleep schedule. If you want to get up earlier, start eating your meals earlier.
  • Change your workout time. If you want to go to bed earlier, exercise early in the day.
  • Be consistent. Go to bed and get up at the same time. If you are changing your sleep schedule, stay consistent for several days, make incremental changes, and stay consistent with each change for several more days.
  • Engage in a bedtime routine. Take a relaxing bath, read, have a hot drink.
  • Consider light therapy. If you can’t get enough outside daylight, there are light therapy boxes you can use indoors. You can even get a prescription for one and have insurance cover it.
  • Take melatonin. It is available over the counter, and from health food stores, and comes in many forms. This can be used to induce sleep at an earlier hour.


If you desire a change in your sleep schedule, consider intentionally changing your circadian rhythm. This can be done by shifting slowly to a new schedule and supporting your bodies sleep needs with well-timed light exposure and meals, and consistency.