If you live with fibromyalgia, it can feel as though your body clock has a mind of its own. Many people talk about a “fibromyalgia body clock” that runs on a completely different timetable to everyone else. Not very helpful when your body seems to be running on a completely different timetable to everyone else.
This is not another generic list of sleep tips. Instead, we are zooming in on your body clock, your circadian rhythm, and looking at how timing (when you sleep, wake, move and see light) can gently support pain, fatigue and brain fog alongside everything else you are already doing. We will also be honest about what the research actually shows, and where we are still making educated guesses.
What you will take away from this
Fibromyalgia seems to mess with the body clock in ways that matter. When your sleep and wake rhythms get disturbed, pain, fatigue and mood often spiral. The strongest signal from the research is not about magic gadgets or expensive supplements; it is about regularity. When you wake up and the difference between your daytime and nighttime patterns seems to matter more than chasing perfect sleep.
Tools like CBT-I (cognitive behavioural therapy for insomnia), morning light and low dose melatonin can help some people feel more in control, but they sit alongside everything else. They are adjuncts, not cures.
If you also have ME/CFS or clear post exertional malaise, pacing and energy envelope management stay front and centre. Any timing tweaks need to work around that reality, not override it.
Here is the reassuring bit: you do not need perfect routines. Tiny, sustainable shifts in timing can still make a difference when you are working with what your body can actually manage right now.
Meet your body clock (and why it matters for fibro)
Deep inside your brain, in a tiny cluster of cells in the hypothalamus, sits your master clock. It keeps roughly twenty four hour time, responds to light (especially in the morning), and helps coordinate hormones like cortisol and melatonin. It also influences body temperature, gut motility, immune signalling and even how you process pain.
Most people’s internal clocks naturally run a touch later than twenty four hours. Without something to anchor them, they gradually drift later and later. For many of us, that anchor is morning light plus a fairly consistent wake up time.
In fibromyalgia and related pain conditions, several studies have noticed a familiar pattern. People are more likely to prefer evenings, describe themselves as “night owls”, show bigger day to day swings in when they fall asleep and wake up, and have altered rhythms of melatonin and cortisol. That does not prove cause and effect, but it fits what many people with fibromyalgia describe: days and nights gradually sliding out of sync, pain and fatigue flaring when sleep becomes chaotic.
What research actually says about the fibromyalgia body clock
The evidence base is still small, but a few themes are emerging that can help us make better informed guesses.
Morning light and a fixed wake time
In one four week trial, people with fibromyalgia were divided into two groups. One group had bright morning light therapy, the other dimmer light. Both groups were also given a stable wake up time and some simple advice about bedtime.
Both groups improved. Pain, mood, day to day function and sleep quality all got better, and the bright light group did not clearly outperform the dim light group. The researchers concluded that regular sleep and wake timing was probably doing most of the heavy lifting, rather than the intensity of the light itself.
Melatonin: modest help, not a miracle
Some older trials in fibromyalgia, and newer work in mixed chronic pain groups, suggest melatonin can modestly improve sleep quality and slightly reduce pain scores for some people, especially over the first few weeks. The effects often fade after about six weeks, though. Doses and formulations vary wildly from study to study – anywhere from one to ten milligrams, immediate release or slow release. We still do not have clear long term safety data or a single “best” dose.
There is also one small trial in ME/CFS that used one milligram of melatonin plus zinc over sixteen weeks and found improvements in fatigue and quality of life. Promising, but not yet replicated.
Melatonin is not suitable for everyone, particularly if you take several other medicines or live with epilepsy, bipolar disorder or more complex health conditions. It can cause morning grogginess, vivid dreams and, less commonly, mood changes. In the UK it is usually prescription only, which is another reason to talk it through with your GP or pain clinic first rather than experimenting on your own.
CBT-I for insomnia
For people with fibromyalgia who also have clear insomnia, CBT-I – a structured talking therapy focused on sleep patterns, thoughts and behaviours around sleep tends to outperform generic “sleep hygiene” advice. It also does better than standard CBT for pain when the main target is broken sleep.
Improvements in pain and mood tend to be smaller than the sleep gains, but they can still be meaningful for some people.
NICE does not currently recommend melatonin or light boxes specifically for fibromyalgia because the evidence is limited. Instead, guidance leans towards multimodal care: pacing, gentle movement within limits, psychological support where appropriate, and CBT-I for those with true insomnia.
The big idea: give your body clock a daily anchor
The most realistic change most of us can make is not fancy or expensive. It is about giving your fibromyalgia body clock a few consistent time signals every day, so it knows what counts as day and what counts as night.
Those anchors might be getting up at roughly the same time most days, seeing natural light not too long after waking, keeping most of your eating, movement and social contact in the daytime, and making your evenings visibly and sensibly “quieter” with softer light and less stimulation.
You do not need to hit all of these. Even one or two clear anchors, done gently and consistently, can start nudging your system in a kinder direction.
Step 1: Choose a realistic wake up window
For many people with fibromyalgia, especially those without post exertional malaise, the single most powerful shift is choosing a regular wake up time and sticking to it on most days.
If your current pattern is all over the place, it is usually unhelpful to suddenly decide you will get up at seven every morning. Instead, look back over the last week and notice when you naturally wake if nobody is forcing you. Use that as your starting point. If you tend to wake somewhere around half past eight or nine, choose a half hour window in that range and aim to be out of bed within that window on most days.
If you also live with ME/CFS or clear post exertional crashes, your anchor might need to be softer and later. The aim is gentle regularity, not dragging yourself out of bed in the middle of a crash just to “protect your rhythm”. You can always experiment with edging your window earlier by fifteen or thirty minutes once things feel more stable.
Step 2: Use light as your “on switch” gently
Light is the main signal for your master clock, but you do not need specialist equipment to begin with. If you can, open the curtains soon after you wake and spend ten to twenty minutes near a window with a drink. On better days you might manage to step outside, even if it is just onto a balcony or front step.
If mornings are your worst time and you tend to wake very late, start from where you are rather than where you think you “should” be. If you usually first see daylight at one in the afternoon, aim to see it at half twelve for a week, then experiment with shifting that earlier in small steps – only if your body tolerates it.
Some people use a bright light box, particularly in winter. These can be helpful in conditions like seasonal affective disorder. In fibromyalgia, though, the best evidence so far suggests that having a regular morning light routine mattered more than hitting a particular brightness. You can treat any gadget as a possible helper, not a cure.
If you have a history of bipolar disorder, significant eye disease or you take medicines that make your skin or eyes more sensitive to light, speak to your doctor before using a light box.
Step 3: Create quiet cues for “night mode”
Evenings are about giving your brain clear signals that it is time to wind down. This does not require a long complicated routine, it is more about drawing a line between “day” and “evening”.
That might look like switching from the main ceiling lights to lamps about an hour before bed, choosing lower stimulus activities such as an audiobook, podcast, familiar television or a paper book instead of fast scrolling, and keeping your largest meals earlier in the evening so you are not trying to sleep on a very full stomach.
Some people with insomnia find blue blocking glasses helpful for a couple of hours before bed, especially if they use screens a lot. Most of the research for these is in general insomnia rather than fibromyalgia specifically, but they are relatively low risk and not usually expensive if you want to try them. Using the night mode or warm colour settings on your phone, tablet or laptop is a simple, free step in the same direction.
If you already have a basic wind down routine, you do not need to add lots of extra steps. The main thing is that your brain can tell, most nights, when day has ended and night has begun.
What about melatonin, light boxes and other circadian “hacks”?
For adults, small doses of melatonin, often in the one to three milligram range, can shift the body clock slightly earlier if taken at the right time, usually one to two hours before your intended bedtime. In some fibromyalgia and chronic pain studies, this has led to better sleep and modest reductions in pain in the short term.
At the same time, it is not a cure for fibromyalgia, and it is not right for everyone. It can cause grogginess, vivid dreams and occasionally changes in mood, and it can interact with other medicines. Because melatonin is prescription only for adults in the UK, it is best thought of as something to explore with your GP or pain team as a time limited trial, not something you put yourself on indefinitely.
Bright light therapy boxes sit in a similar category. They can be helpful in certain circadian rhythm disorders and seasonal affective disorder, but in fibromyalgia the clearest message so far is that a regular morning routine matters more than a particular lux number. For people with ME/CFS we do not yet have strong evidence that bright light therapy improves post exertional symptoms or core fatigue, and it is not a specific NICE recommendation. If you do experiment, it is wise to start gently and keep an eye on boom and bust patterns, where a brief improvement leads to a big uptick in activity and then a crash.
Blue blocking glasses and software night modes fall into the “low risk helper” category. They can make it easier for some people to fall asleep and stay asleep, especially in our very screen heavy evenings, but they are unlikely to transform fibromyalgia on their own.
If you live with PEM or ME/CFS as well as fibro
Many people reading this sit somewhere on a fibromyalgia ME/CFS Long Covid overlap. You might recognise delayed crashes after effort, have very limited energy to spare, or face days when getting out of bed at all feels like climbing a mountain.
In that context, pacing and energy envelope management remain non negotiable. Any body clock work needs to be gentle enough that it does not trigger post exertional malaise. It is completely fine if your wake window is later than average, if it has to flex on crash days, or if family, caring roles or appointments mean your timing is far from textbook.
A useful way to picture this is to imagine body clock work as sandpaper rather than a hammer. You are smoothing out a few rough edges, not remodelling the whole structure. If any suggestion in this article feels as though it would tip you into a crash, it is simply not the right step for you at the moment.
Making this doable when you are already exhausted
When you are dealing with chronic pain, fatigue and brain fog, even small changes can feel like a lot. It helps to treat this as a series of tiny experiments rather than a big lifestyle overhaul.
You might begin with one simple anchor, such as opening the curtains within fifteen minutes of waking most days, or sitting in your usual spot by a window with a drink for ten minutes. Set a reminder on your phone, or leave a note where you will see it, so you do not have to hold it in your head.
On more difficult days, the only realistic goal might be to keep today’s wake time within an hour of yesterday’s, if that is possible. If you share a home, you could ask a partner, family member or housemate to help with easy cues, opening the curtains or switching to lamps in the evening at an agreed time.
If a week or two goes off track, that is not failure. It is simply information about what your body and life are like at the moment. You can always restart from where you are, not where you were.
When to talk to your GP or specialist
Self help changes can be useful, but they are not a substitute for proper assessment. It is worth speaking to your GP or specialist if you have had very little sleep for months despite trying basic changes, if someone has noticed loud snoring, gasping or pauses in your breathing at night, if you wake unrefreshed with morning headaches, or if your mood has dropped very low or you are having thoughts of self harm.
It is also sensible to get medical advice before using melatonin or bright light therapy if you have a history of bipolar disorder or psychosis, or if you are already taking several medicines that make you drowsy.
In that appointment, you can ask about referral options for services that offer CBT-I, whether melatonin might have a role in your specific case, and whether any of your current medicines might be making your body clock later or your sleep worse.
Next read: Pain and crashes fit together; have a look at our guide to fibromyalgia and sleep.
Key resources and references
If you would like to read more or share information with your GP, these are good starting points:
NICE guideline NG193 on chronic primary pain in over sixteens, which includes fibromyalgia.
The Royal College of Physicians guidance on diagnosing fibromyalgia.
The Burgess trial on morning light and stabilising sleep and wake timing in fibromyalgia.
Recent reviews of CBT-I in people who have both fibromyalgia and insomnia.
Disclaimer
This article offers general information about fibromyalgia, sleep and circadian rhythms. It is not a substitute for individual medical advice. If you are experiencing chronic pain, fatigue or other worrying symptoms, please speak with your GP or a relevant specialist. Everyone’s situation is different, and what helps one person may not be right for another.
Written by Stems From The Gut
Created by someone living with fibromyalgia, chronic pain and messy gut issues. I write in plain English to help you feel more informed and less alone. You can read more about how we use evidence on the Authors and Medical Stance page.