Table of ContentsView AllTable of ContentsWhat It IsHow It WorksWhat It HelpsHow To Do ItSafety/ConsiderationsFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
What It Is
How It Works
What It Helps
How To Do It
Safety/Considerations
Frequently Asked Questions
Light therapy is a common treatment for sleep disorders and mood disorders that affect sleep. Also calledphototherapyorbright light therapy, it involves using a special lightbox at home, or sometimes simply getting sun exposure at the right time of day.
It might sound too simple to help with such a big problem, but a growing body of scientific knowledge shows that it can work. You may benefit from light therapy if you have sleep problems related to:
Christopher Furlong / Getty Images
What Is Light Therapy?
Light therapy is an intentional and focused use of sunlight or simulated sunlight to treat symptoms. This is typically done with a specially designed lightbox that puts out 10,000 lux. That’s bright enough to be effective but substantially dimmer than the sun, so it’s safe for your eyes.
While your healthcare provider may recommend it, light therapy usually is something you do yourself, at home, and it doesn’t require a prescription or medical supervision. However, you’ll need to acquire your own lightbox. (That may be more affordable than you think. We’ll discuss that below.)
Light therapy is simple. It typically involves:
Your healthcare provider can help you fill in those specifics based on your diagnosis, current research, and their clinical experience.
How Does Light Therapy Work?
The purpose of light therapy is to reset yourcircadian rhythm. Circadian rhythms are cycles of physical and mental functions that take place, in most people, over the course of a 24-hour period. Scientists don’t fully understand how these cycles work, but research is ongoing because they are important to many aspects of health.
Most living things develop a circadian rhythm that’s in sync with the light and dark cycles in their environment.In fact, scientists have found sensors in the back of human eyes that detect light and dark patterns and use them to set the circadian rhythm.
What Is the Circadian Rhythm?The circadian rhythm is a natural process in your brain that regulates physiological changes that determine your sleep-wake cycle. A normal circadian rhythm rests roughly every 24 hours and is in tune with the rotation of the Earth.
What Is the Circadian Rhythm?
The circadian rhythm is a natural process in your brain that regulates physiological changes that determine your sleep-wake cycle. A normal circadian rhythm rests roughly every 24 hours and is in tune with the rotation of the Earth.
The Sleep-Wake Cycle
The sleep-wake cycle is one of the main functions of the circadian rhythm. When things work like they’re supposed to, you’re awake for roughly 16 hours and asleep for eight.
The body performs very different functions depending on where you are in the sleep-wake cycle. For instance, cell growth and mental function increase while you’re awake, and your metabolic rate and body temperature drop when you’re asleep.
Hormones are an important part of these cycles. When things are working properly, about two hours before you wake up, the body releases increased amounts ofadrenalineand cortisol to prepare you for the day’s activity.Melatonin, a hormone that promotes sleep, increases in response to darkness and drops off rapidly when you’re exposed to bright light.
Many other processes go on that influence when you get tired and when you’re most alert and energetic. People who aren’t exposed to enough light during the day—or even not light from the right spectrum—can have their circadian rhythms thrown off.
Resetting Your Circadian Rhythm
A growing body of research suggests that resetting your circadian rhythm with light therapy is a beneficial aspect of treatment for several conditions.
In most cases, light therapy is recommended for first thing in the morning. (“Morning” in this case means within an hour of when you wake up.) For sleep disorders, between 30 and 40 minutes of light therapy is typical, but it may be longer for some conditions.
Keep your healthcare provider’s guidance in mind when setting up your lightbox so you’re in the optimal distance range. You can use the lightbox wherever it works best with your morning routine, such as:
You can go about your regular activities—eat, check email, work on the computer—while also receiving light therapy. The important thing is that it’s consistent and (unless your healthcare provider recommends a different time) soon after you wake up, whatever time of day that might be.
What About Sunlight?
It is possible to use the sun for light therapy, as long as your goal is resetting your circadian rhythm to match the natural day and night cycle. After all, lightboxes are meant to provide simulated sunlight.
If you’re consistently able to take a walk, spend time outside, or sit inside near a window in the morning, this may be an option you want to try.
Conditions Light Therapy May Help
Sometimes, a person’s circadian rhythm is altered and doesn’t function properly. This can be related to certain genetic abnormalities or medical conditions. It can also be due to shift work or jet lag, which disrupt your usual light-dark cycles. It can even happen because of late-nightexposure to light from electronic devices.
When you have insomnia, other sleep disorders, or diseases that disrupt sleep, your body may benefit from extra clues as to what time of day it is.
If you work nights, have regularly changing shifts, or travel a lot, you may need to adjust your sleep-wake cycle to go against your body’s natural cycles and the clues it takes from the rising or setting sun.
Insomnia
Research on light therapy for insomnia suggests a benefit. In a 2016 review of studies on light therapy for insomnia, researchers concluded that evidence showed light therapy was effective for treating insomnia, including insomnia related toAlzheimer’s diseaseand related dementias (ADRD).
A 2017 paper specifically on light therapy for people with ADRD cited evidence that light therapy improved nighttime sleep, increased daytime wakefulness, and reduced evening agitation and behavioral problems linked to the disease, all while avoiding potential side effects of medications.
European guidelines for insomnia published in 2017 said evidence for light therapy was of low quality and needs further study, but they issued a weak recommendation in favor of using it.
Circadian Rhythm Sleep Disorders
Several sleep disorders are directly linked to disruptions in the circadian rhythm, making a reset option especially attractive. These circadian rhythm sleep disorders are:
Light therapy is one of the primary treatments for this group of disorders.
A 2015 paper emphasizes the importance of appropriately timed light plus melatonin and improved sleep hygiene for these disorders.The 2016 review mentioned above cited evidence of light therapy working for circadian rhythm sleep disorders in general.And a 2019 study suggested light therapy for shifting the timing of sleep in delayed and advanced sleep phase disorders.
Some healthcare providers recommend late-evening light therapy for people with advanced sleep phase disorder, since the goal is staying awake longer.
Seasonal Affective Disorder
Research on light therapy for treating SAD goes back decades, and it’s one of the most recommended treatments. Reviews of literature from 2019 and 2020 call for larger, high-quality clinical trials but cite the effectiveness of the treatment.
Your healthcare provider may recommend light therapy in the morning, but for SAD symptoms, it’s sometimes recommended for later in the day to counter the effects of the early fall and winter sunset.
While light therapy is a standard approach to treating SAD, be sure to follow all of your healthcare provider’s treatment recommendations rather than trying to rely on a lightbox alone.
Choosing the Best Lightbox for SAD
Depression
Depression, also called major depressive disorder or clinical depression, is yet another condition linked to circadian rhythm disruption.
People with depression are especially likely to have insomnia, and insomnia can contribute to the development of depression. Each condition may lead to the other, and they can make each other worse.
Treating sleep problems can have the added benefit of alleviating depression, and light therapy can play a role in that. One study called light therapy an “efficient antidepressant strategy,” either alone or in addition to other treatments.
A review of studies on light therapy for depression states that antidepressant drugs plus light therapy were more effective than antidepressants alone. It also found that light therapy may improve people’s response to antidepressants.
Light therapy is best considered a possible add-on therapy rather than a replacement for antidepressants. Be sure to follow your healthcare provider’s treatment recommendations.
Sleep Better With Depression
Other Conditions
Research has suggested that light therapy may benefit people with many other conditions, as well. These include:
While aging isn’t exactly a medical condition, some studies have found that many older people, and especially those who live in group-home settings, have circadian rhythm disruptions that are tied to spending most of their time in dim lighting. Researchers have recommended brighter lighting that stimulates the circadian rhythm in common areas of these facilities.
Light Therapy at Home
When using light therapy, it’s important to ask your healthcare provider for specific instructions, such as how far from the lightbox you should be, how long you should use it, and what time of day may be best for you.
The American Thoracic Society has published patient information on light therapy and makes the following recommendations:
Buying a Light Box
Most commercially available lightboxes put out 10,000 lux. Ask your healthcare provider if this is an appropriate light level for you. They may also recommend certain brands or styles.
The Cost
Prices range from about $20 up to a few hundred. They’re available from many online retailers and drug or medical supply stores. You may also be able to find one secondhand online. Before you buy one, though, check with your insurance company to see if they’ll help cover any of the cost.
Types of Lightbox
When deciding on the size of box you’d like, consider where you’d like to put it and whether you might need to move it frequently, such as taking it out of your home office on days off. If you travel frequently, you may want a portable one.
Get a lightbox that puts out low levels of UV light, which can be damaging to your skin.
Other Considerations
Give it time—it may take several weeks to see a benefit from light therapy. Make it a simple part of your routine so it’s easy to be consistent.
Other types of light therapy devices are available as well, including visors andglasses. If you think these might be a better option for you, ask your healthcare provider.
Light Therapy Safety and Considerations
In some people with bipolar depression, light therapy can cause mania or hypomania. However, this is rare.
Photosensitivity
Some medications and supplements can causephotosensitivity, a reaction that can lead to a rash or make you sunburn easily. If you’re taking one of them, talk to your healthcare provider about whether light therapy is safe for you. These include:
If you havelupus-related photosensitivity, talk to your rheumatologist before using light therapy.
Photosensitivity During Chemotherapy
Eye Diseases
Can light therapy cure insomnia?
It can help some people readjust their sleep routine and overcome insomnia. Research shows that higher light intensity has helped those with insomnia, especially people who have Alzheimer’s disease ordementia-related insomnia.But it may not help all types of sleep problems.
Why is it important to regulate your circadian rhythm?
It’ll help ensure you get enough sleep, but on top of that, regulating your circadian rhythm can influence your appetite and digestion, heart rate, body temperature, oxygen use, mood, fluid balance, hormonal secretions, and other important physiological processes.
Can light therapy help with jet lag?
A Word From Verywell
Sleep is a fundamental need for your physical and mental health, and mood disorders can have a significant impact on your life. If your current treatments aren’t providing enough relief, talk to your healthcare provider about treatment options, including light therapy. It might be that a simple addition to your daily routine could provide a significant benefit, especially when added to other science-backed treatments.
More Drug-Free Ways to Sleep Better
23 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Institutes of Health: National Institute of General Medical Sciences.Circadian rhythms.
Figueiro MG.Light, sleep and circadian rhythms in older adults with Alzheimer’s disease and related dementias.Neurodegener Dis Manag. 2017;7(2):119-145. doi:10.2217/nmt-2016-0060
Encyclopaedia Britannica.Circadian rhythm.
National Institutes of Health: National Heart, Lung, and Blood Institute.Insomnia.
van Maanen A, Meijer AM, van der Heijden KB, Oort FJ.The effects of light therapy on sleep problems: A systematic review and meta-analysis.Sleep Med Rev. 2016;29:52-62. doi:10.1016/j.smrv.2015.08.009
Riemann D, Baglioni C, Bassetti C, et al.European guideline for the diagnosis and treatment of insomnia.J Sleep Res. 2017;26(6):675-700. doi:10.1111/jsr.12594
Tagaya H, Murayama N, Fukase Y.Circadian rhythm sleep-wake disorder (circadian rhythm sleep disorder).Nihon Rinsho; 73(6):942-948. Article in Japanese; abstract referenced.
Abbott SM, Reid KJ, Zee PC.Circadian rhythm sleep-wake disorders.Psychiatr Clin North Am. 2015;38(4):805-823. doi:10.1016/j.psc.2015.07.012
Culnan E, McCullough LM, Wyatt JK.Circadian rhythm sleep-wake phase disorders.Neurol Clin. 2019;37(3):527-543. doi:10.1016/j.ncl.2019.04.003
National Jewish Health.Circadian rhythm sleep disorders: Treatment.
Maruani J, Geoffroy PA.Bright light as a personalized precision treatment of mood disorders.Front Psychiatry. 2019;10:85. Published 2019 Mar 1. doi:10.3389/fpsyt.2019.00085
Nussbaumer-Streit B, Forneris CA, Morgan LC, et al.Light therapy for preventing seasonal affective disorder.Cochrane Database Syst Rev. 2019;3(3):CD011269. Published 2019 Mar 18. doi:10.1002/14651858.CD011269.pub3
Pjrek E, Friedrich ME, Cambioli L, et al.The efficacy of light therapy in the treatment of seasonal affective disorder: A meta-analysis of randomized controlled trials.Psychother Psychosom. 2020;89(1):17-24. doi:10.1159/000502891
Pandi-Perumal SR, Monti JM, Burman D, et al.Clarifying the role of sleep in depression: A narrative review.Psychiatry Res. 2020;291:113239. doi:10.1016/j.psychres.2020.113239
Penders TM, Stanciu CN, Schoemann AM, Ninan PT, Bloch R, Saeed SA.Bright light therapy as augmentation of pharmacotherapy for treatment of depression: A systematic review and meta-analysis.Prim Care Companion CNS Disord. 2016;18(5):10.4088/PCC.15r01906. Published 2016 Oct 20. doi:10.4088/PCC.15r01906
Gold AK, Kinrys G.Treating circadian rhythm disruption in bipolar disorder.Curr Psychiatry Rep. 2019;21(3):14. Published 2019 Mar 2. doi:10.1007/s11920-019-1001-8
Fifel K, Videnovic A.Light therapy in Parkinson’s disease: Towards mechanism-based protocols.Trends Neurosci. 2018;41(5):252-254. doi:10.1016/j.tins.2018.03.002
Santos MAD, Conceição APD, Ferretti-Rebustini REL, Ciol MA, Heithkemper MM, Cruz DALMD.Non-pharmacological interventions for sleep and quality of life: A randomized pilot study.Rev Lat Am Enfermagem. 2018;26:e3079. Published 2018 Nov 14. doi:10.1590/1518-8345.2598.3079
Schotland H.Artificial bright light therapy for circadian rhythm sleep-wake disorders.Am J Respir Crit Care Med. 2019;200(6):P11-P12. doi:10.1164/rccm.2006P11
van Maanen A, Meijer AM, van der Heijden KB, Oort FJ.The effects of light therapy on sleep problems: A systematic review and meta-analysis.Sleep Medicine Reviews. 2016;29:52-62. doi:10.1016/j.smrv.2015.08.009
Philpott JM, Narasimamurthy R, Ricci CG, et al.Casein kinase 1 dynamics underlie substrate selectivity and the PER2 circadian phosphoswitch.eLife. 2020;9:e52343. doi:10.7554/elife.52343
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
