“Headache Medicine Causes Headaches”—Can Overuse of Over-the-Counter Medications Lead to Chronic Headaches? A Specialist Sounds the Alarm on the Truth Behind Medication-Overuse Headaches
Amid rising medical costs, the government is promoting self-medication. The idea is that people should manage their own health by using over-the-counter (OTC) medications for minor ailments. This approach is expected to help reduce the burden on medical institutions and curb medical costs.
On the other hand, one issue that is often overlooked is the incorrect use of these medications based on self-diagnosis.
Drugstores stock a wide variety of headache medications, and they can also be easily purchased online. Many people likely take them every time they get a headache, assuming that “since they’re over-the-counter, they must be safe.”
However, in recent years, headache specialists and addiction specialists have raised concerns about “medication overuse headache (MOH),” which is caused by overuse of over-the-counter medications.
You take headache medicine, but the headache doesn’t go away. In fact, the headaches may even be getting worse than before—according to Dr. Satoshi Ozaki, a neurosurgeon and chairman of the Ebina Neurological Clinic , “In some cases, the cause lies in the headache medicine itself.” We asked him about the reality of over-the-counter medication dependence and medication overuse headache (quotes below are from Dr. Ozaki).
“Medication Overuse Headache”: How Taking Too Many Painkillers Can Make Headaches Chronic
“Medication-overuse headache refers to a headache caused by the very medication you were taking to relieve it. Frequent use of pain relievers makes the brain hypersensitive to pain, making you more prone to headaches whenever the medication’s effects wear off.”
While patients themselves may think, “I’m taking the medicine because I have a headache,” in reality, it is not uncommon for them to be in a situation where “the headache persists precisely because they keep taking the medicine.”
“It is believed that using many over-the-counter pain relievers for 10 or more days a month increases the risk of medication-overuse headache.”
Over-the-counter headache medications may contain not only analgesic ingredients but also ingredients with sedative or stimulant effects. The following ingredients, in particular, require caution:
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・Caffeine anhydrous
xml-ph-0000@deepl.internal has a sedative effect and helps alleviate anxiety and tension. Because it not only suppresses pain but also makes it easier to feel “relieved” or “calm,” it can easily lead to psychological dependence, where people feel that “nothing else works except this medicine.”
Bromovaleryl urea is a substance with sedative and hypnotic effects; its mechanism of action is similar to that of barbiturate-based drugs, which were once used in sleeping pills and other medications. In recent years, it has been found in over-the-counter medications that have become problematic due to overdoses among young people, and addiction specialists have issued warnings about it.
“These ingredients do not immediately cause dependence. However, because they make it easy to feel that the medication ‘worked,’ this often leads to an increase in the frequency of use, which can result in medication-overuse headaches or dependence on over-the-counter medications.”
One thing that’s often overlooked is the anhydrous caffeine found in headache medicine.
“Over-the-counter headache medications also contain anhydrous caffeine. This is because it enhances the effectiveness of the pain reliever and helps alleviate the drowsiness and fatigue associated with headaches.”
However, caution is also advised.
“In addition to the anhydrous caffeine in headache medicine, people who drink coffee, black tea, green tea, or energy drinks may be increasing their total caffeine intake without even realizing it.”

Excessive caffeine intake can lead to health problems.
“Caffeine is a common substance, but excessive intake can cause insomnia, palpitations, anxiety, and hand tremors. In severe cases, arrhythmias and impaired consciousness have also been reported.”
People who habitually consume caffeine may suffer from withdrawal symptoms.
・Headaches when not drinking coffee
・Severe drowsiness
・Persistent fatigue
・Decreased concentration
“These are symptoms of caffeine withdrawal, and it’s not uncommon for people to fall into a vicious cycle when headaches are added to the mix.”
“Just because it’s an over-the-counter medication doesn’t mean it’s safe”
Self-medication is, in principle, a system designed to maintain health through the appropriate use of medication. However, because over-the-counter medications can be purchased without a doctor’s examination, there is a risk of taking them for extended periods without identifying the cause of the symptoms.
“Just because a medication is over-the-counter doesn’t mean it’s safe. If you’re taking headache medication more frequently, feel anxious when you don’t have it on hand, or feel that it’s becoming less effective than before, please visit a headache clinic or a neurologist.”
Headaches can sometimes be a symptom of serious underlying conditions, such as stroke or brain tumors.
“If your headaches persist, don’t just assume it’s ‘just a headache.’ Instead of continuing to take over-the-counter medications based on your own judgment, please consult a specialist if necessary.”
If your headache doesn’t go away even after taking headache medication, it could be a sign that “the headache medication is causing the headache”—and if that’s the case, the suffering becomes endless. Precisely because we live in an era of self-medication, it’s essential to know how to use over-the-counter medications properly.
