Are painkillers actually making your daily headaches worse?

If you have a headache most days of the month and rely on over-the-counter painkillers to get through, this article is for you. Medication-overuse headache (MOH) is one of the most prevalent — and most missed — causes of chronic daily headache in the world. Recognising it changes everything; treating it almost always means using fewer painkillers, not more.

What MOH actually is

Medication-overuse headache is a secondary headache disorder in which regular, frequent use of acute headache medications paradoxically causes the headaches to occur more often and become harder to treat. Diagnosis is formally defined in the International Classification of Headache Disorders (ICHD-3) as headache on ≥15 days per month for >3 months, in a patient who is regularly taking acute headache medication for ≥10–15 days per month (Headache Classification Committee, 2018).

The medications most commonly implicated are:

• Codeine-containing analgesics (≥10 days/month).
• Combination tablets such as caffeine-paracetamol-codeine (≥10 days/month).
• Triptans (≥10 days/month).
• NSAIDs (ibuprofen, naproxen, aspirin) (≥15 days/month).
• Plain paracetamol (≥15 days/month).

Global prevalence is estimated at 1–2% of the general population — making MOH one of the most common medical conditions worldwide, ahead of stroke and diabetes (Diener et al., 2016).

How can a painkiller cause more pain?

Three biological mechanisms have been proposed and partly validated:

1. Receptor adaptation. Frequent exposure to analgesics produces downregulation of pain-modulating receptors (mu-opioid, serotonergic, prostaglandin pathways). The pain-dampening system becomes less responsive between doses.
2. Central sensitisation. Repeated brief pain-relief windows followed by rebound nociceptive signalling drives upregulation of central pain processing — the trigeminocervical complex becomes hyperexcitable (Coppola et al., 2018).
3. Behavioural conditioning. Anticipatory pain and the "I had better take one before it gets worse" reflex reinforce the cycle and reduce coping with milder discomfort.

How to spot it

A few questions identify MOH with high reliability:

• Are you taking a painkiller for headache on more than 10 days per month?
• Do you wake with a headache most mornings?
• Does the relief from a tablet last only a few hours before the headache returns?
• Has the underlying headache changed — from clear episodes to a daily background ache with occasional flares?
• Have your previously effective painkillers stopped working as well?

Two or more "yes" answers, especially in someone with a pre-existing migraine or tension-type headache, strongly suggest MOH.

What the evidence says about treatment

The cornerstone of treatment is structured medication withdrawal. A landmark Cochrane review and subsequent practice guidelines confirm that complete withdrawal of the overused medication for 4–8 weeks produces marked headache improvement in 60–70% of patients, with effects sustained at 1 year (Chiang et al., 2016).

Two withdrawal patterns are used:

• Abrupt withdrawal — usually for simple analgesics, NSAIDs and triptans, with a 1–2 week predictable "withdrawal headache" worse than baseline, then steady improvement.
• Gradual taper — preferred when an opioid is being withdrawn, or in patients with significant anxiety about withdrawal.

Bridging medications during the withdrawal window — such as a short prednisolone course, a low-dose amitriptyline, or specific anti-CGRP migraine preventatives — are increasingly used and reduce withdrawal severity (Diener et al., 2020).

The role of physiotherapy in MOH

Once medication is withdrawn, the underlying primary headache (migraine, tension, cervicogenic) becomes visible again. This is where targeted physiotherapy comes into its own:

• Upper cervical mobilisation for cervicogenic and tension contributions.
• TMD assessment — overlap with TMD is common in chronic-daily-headache patients.
• Posture, ergonomics, sleep regularity — the trigger stack reduction described in our migraine triggers article.
• Education and reassurance — patients often fear withdrawal more than the headache itself; structured education reduces relapse dramatically.

A 2019 RCT of combined manual therapy + medication withdrawal vs. withdrawal alone showed superior outcomes for the combined arm at 12 months (Krøll et al., 2019).

What the withdrawal week looks like in practice

• Days 1–4: Worse than baseline headache, often with nausea, fatigue and disturbed sleep. The peak is real, but predictable.
• Days 5–10: Gradual softening of the daily background ache. Sleep starts to return.
• Days 10–21: The original underlying headache pattern re-emerges — usually less severe and less frequent than before MOH started.
• Weeks 4–8: Most patients see a 50% or greater reduction in headache days/month from baseline.

Prevention of relapse

The key practical rules are:

1. Limit acute headache medications to ≤2 days per week (≤8 days per month).
2. For patients with frequent migraine, ensure an evidence-based preventative is in place (propranolol, candesartan, amitriptyline, topiramate, anti-CGRP — depending on co-morbidities).
3. Treat the cervical and TMD contributions actively.
4. Keep a headache diary for at least 12 weeks post-withdrawal.

The takeaway

If you reach for a painkiller every day for headache, the relief you feel is most likely buying you tomorrow's headache. The cycle is universally under-recognised — many people have been in it for years without anyone naming it. The good news is that MOH is one of the most rewarding conditions in headache medicine: 6–8 weeks of structured withdrawal, combined with proper treatment of the underlying headache (cervical, jaw, lifestyle), routinely transforms a daily headache pattern back into manageable monthly episodes. The first step is to add up the days; if you are at 15+ per month on painkillers, the conversation with your GP and a specialist physiotherapist is the most useful one you will have this year.