Sleep restriction therapy is a treatment for insomnia that limits the time you spend in bed so that the time you do spend there is mostly sleep. The Sleep Foundation describes it as a multistep, multi-week process that initially restricts the time you spend in bed overnight, with the aim of raising sleep efficiency (Sleep Foundation). It is one part of CBT-I, the first-line treatment for chronic insomnia. This guide explains how the sleep window works, what the research shows and who should not try it alone. It is for education only and is not a treatment plan.
Already keeping a diary? Work out your numbers with the sleep efficiency calculator.
Before you start. This approach can make you sleepier at first. Some people should not use it without a doctor, including those with bipolar disorder, seizure disorders or untreated sleep apnea. Talk to a doctor or a trained CBT-I provider first. See the safety section below.
What Is Sleep Restriction Therapy?
People with insomnia often spend a long time in bed awake. The extra time in bed can make sleep lighter and more broken. The American Academy of Sleep Medicine (AASM) says sleep restriction therapy is designed to enhance sleep drive and consolidate sleep by limiting time in bed to match the person’s sleep duration (AASM guideline). Cleveland Clinic frames it as fixing the mismatch between how much you can sleep and how much time you give yourself in bed (Cleveland Clinic).
The name is misleading. You are not asked to sleep less. You are asked to spend less time in bed so sleep becomes deeper and more continuous. The urge to sleep that builds while you are awake is the engine, called sleep pressure. Read what sleep pressure is for the idea behind it.
How The Sleep Window Is Set
The window comes from a sleep diary. The Sleep Foundation says you log your sleep every day for one to two weeks, then your average total sleep time sets your time in bed, and bedtime and wake time are chosen to match (Sleep Foundation). One trial protocol started the window at average diary sleep time plus 30 minutes, with a minimum of 6 hours in bed (Pchelina et al. 2020). The Sleep Foundation also advises that if your average sleep is under six hours, you plan for six hours in bed (Sleep Foundation). Your clinician may set the floor a little differently.
Sleep efficiency is the share of your time in bed that you actually sleep. The common thresholds are:
| Sleep Efficiency | What Usually Happens to the Window |
|---|---|
| Below 85 percent | Shorten time in bed, if you are not sleepy |
| 85 to 90 percent | Keep the schedule |
| Above 90 percent | Lengthen time in bed, if you do not feel you have had enough sleep |
Thresholds are from the Sleep Foundation (Sleep Foundation). Changes are made in steps of 15 minutes, once a week (Sleep Foundation). The window then grows gradually as sleep becomes more consistent (Sleep Foundation). Calculate your own efficiency with the sleep efficiency calculator and track the trend with a diary.
What The Evidence Shows
Sleep restriction is one of the better-studied pieces of CBT-I.
- Guidelines. The AASM suggests clinicians use sleep restriction therapy as a single-component therapy. The recommendation is conditional, and the evidence quality is low, based on 6 trials (AASM guideline). The American College of Physicians recommends CBT-I as the first treatment for adults with chronic insomnia (ACP 2016).
- Meta-analysis. A 2021 analysis of 8 randomized trials found a large drop in insomnia severity and better sleep efficiency, shorter time to fall asleep and less time awake at night. Total sleep time did not change (Maurer et al. 2021). Most studies had a high risk of bias and few had long follow-up, so the authors describe the benefit as short term.
- Earlier review. A 2014 review found moderate to large improvements in diary-measured time to fall asleep, time awake at night and sleep efficiency, and a small gain in total sleep time (Miller et al. 2014).
The Hard First Weeks
Expect to feel more tired before you feel better. The AASM warns that potential harms may occur in the early phases of treatment, such as increased daytime sleepiness, which typically fade as sleep improves and time in bed is extended. It also notes that sticking with the plan can be hard (AASM guideline). The Sleep Foundation names sleepiness as the main risk (Sleep Foundation).
The daytime sleepiness matters for safety. Be careful with driving, machinery and other tasks that need full attention while the window is tight. Our guide to recovering from a missed night covers similar cautions.
Who Should Not Do It Alone
The AASM flags possible contraindications in high-risk occupations, mania or hypomania, poorly controlled seizures and excessive daytime sleepiness (AASM guideline). The Sleep Foundation says it is not appropriate without a doctor’s input for people who:
- work in transportation, construction or healthcare,
- have a major illness or had recent surgery,
- have untreated sleep apnea,
- have an uncontrolled seizure disorder, or
- have untreated bipolar disorder.
Source: Sleep Foundation. A trial protocol also excluded people with untreated severe sleep apnea, restless legs, pregnancy, high suicide risk and severe depression or anxiety, and advised flexible windows for older adults (Pchelina et al. 2020). If your sleep problem could be linked to anxiety, see insomnia vs anxiety.
Gentler Versions
The Sleep Foundation describes sleep compression as a gentler version, often used with older adults (Sleep Foundation). It cuts time in bed gradually instead of all at once. In a 2025 trial of 234 people, sleep compression did not match standard sleep restriction and produced smaller improvements (Jernelov et al. 2025). The AASM guideline did not address compression (AASM guideline). Gentler is not always better, so ask a clinician which fits you.
Habits That Go With It
Sleep restriction rarely works alone. The Sleep Foundation pairs it with these habits:
- A fixed wake time. Keep a consistent alarm every day (Sleep Foundation).
- No daytime naps. The Sleep Foundation says not to nap during the fixed-schedule week (Sleep Foundation). The NHS also advises against daytime naps for insomnia (NHS).
- Use the bed only for sleep and sex. If you cannot sleep or you are awake for more than about 10 minutes, get up and return only when sleepy (Sleep Foundation).
For the broader toolkit, see the CBT-I hub, how to beat insomnia and sleep hygiene 101. If you track with a device, read sleep tracking and insomnia, since obsessing over numbers can backfire.
How To Get Help
Cleveland Clinic calls CBT-I the first-line treatment for insomnia and says it usually takes six to eight sessions (Cleveland Clinic). The Sleep Foundation says CBT-I can come from a doctor, counselor, therapist or psychiatrist trained in it, and that digital CBT-I is effective in children, adolescents and adults, with results similar to in-person care, although few direct comparisons exist (Sleep Foundation). The NHS says CBT can be delivered in person, online or on the phone (NHS).
When To See A Doctor
The NHS suggests seeing a GP if changing your sleeping habits has not helped, you have had trouble sleeping for months, or insomnia makes daily life hard to cope with (NHS). Start there, since a doctor can also check for sleep apnea and other causes before a sleep window is set. You can read more in our insomnia guide.
FAQs About Sleep Restriction Therapy
How Does Sleep Restriction Therapy Work?
It limits time in bed to your average sleep time to build sleep drive and consolidate sleep (AASM guideline).
How Long Does Sleep Restriction Therapy Take To Work?
It is a multi-week process, with the window adjusted weekly (Sleep Foundation). I did not find an authoritative page giving a set number of weeks, and trial benefits are short term (Maurer et al. 2021).
What Are The Side Effects Of Sleep Restriction Therapy?
Increased daytime sleepiness is the main one, mostly in the early phase (AASM guideline).
What Is A Good Sleep Efficiency?
The common aim is about 85 to 90 percent. Under 85 the window is shortened and over 90 it is lengthened (Sleep Foundation).
Can I Do Sleep Restriction Therapy Myself?
Some people try a self-guided version, but a clinician or trained provider is safer, and it is not suitable for everyone (Sleep Foundation).
Is Sleep Restriction Therapy The Same As CBT-I?
No. It is one component of CBT-I, which also includes habits like stimulus control (Sleep Foundation).