Headaches are the most commonly reported side effect of Lexapro (escitalopram), and they typically show up within the first few days of starting the medication. The good news: for most people, they resolve within the first week. The reason they happen in the first place comes down to how the drug changes your brain chemistry.
How Lexapro Triggers Headaches
Lexapro works by blocking the reabsorption of serotonin in the brain, leaving more of it available between nerve cells. Serotonin doesn’t just regulate mood. It also plays a direct role in controlling blood vessel diameter, pain signaling, and muscle tension, particularly in the head and neck. When you first start taking Lexapro, your brain is adjusting to a sudden shift in serotonin levels, and that adjustment period can cause blood vessels to constrict or dilate in ways that trigger headache pain.
This is essentially the same reason serotonin has long been linked to migraines. Your brain’s vascular system is sensitive to serotonin fluctuations, and any rapid change, whether from a new medication or from the body’s own chemistry, can produce head pain. Once your brain adapts to the new serotonin baseline, the headaches generally stop.
How Common They Are
Headaches occur in more than 1 in 100 people who take escitalopram, placing them in the “common” side effect category. In FDA clinical trials of Lexapro, headache was identified as the single most frequent treatment-emergent side effect, occurring more often in the escitalopram group than in those taking a placebo. That gap between drug and placebo groups confirms this isn’t just coincidence or the underlying condition causing the pain.
How Long They Last
Most Lexapro headaches resolve within the first week of treatment. The NHS recommends talking to your doctor if they persist beyond that point or become severe. During that initial week, staying well hydrated, resting, and limiting alcohol can help. The headaches tend to be mild to moderate, more of a dull pressure than a sharp or throbbing pain, though individual experiences vary.
If your doctor adjusts your dose upward at any point during treatment, you may experience a brief return of headaches as your brain recalibrates to the higher serotonin level. This follows the same pattern: a few days of discomfort, then resolution.
Safe Pain Relief While on Lexapro
Acetaminophen (Tylenol) is generally the safest over-the-counter option for headache relief while taking Lexapro. Ibuprofen (Advil, Motrin) and other NSAIDs carry a specific concern: taking them alongside an SSRI like Lexapro increases the risk of bleeding. Both drugs independently affect how your blood clots, and the combination can amplify that effect. This risk is higher in older adults and people with kidney or liver disease.
If you prefer ibuprofen or find acetaminophen ineffective, it’s worth discussing the bleeding risk with your pharmacist or doctor. For occasional, short-term use in otherwise healthy people, the risk is small, but it’s not zero. Alcohol should also be limited or avoided, both because it worsens Lexapro’s side effects like dizziness and drowsiness, and because combining alcohol with ibuprofen further raises the chance of stomach bleeding.
Headaches From Stopping Lexapro
Headaches don’t only happen when you start Lexapro. They can also appear when you stop it. Escitalopram carries a moderate risk of antidepressant discontinuation syndrome, a cluster of withdrawal-like symptoms that typically begin two to four days after stopping the medication. Headache is one of the hallmark symptoms, often accompanied by fatigue, achiness, sweating, and a general flu-like feeling.
This is why doctors recommend tapering off Lexapro gradually rather than stopping abruptly. If you do experience discontinuation headaches, over-the-counter pain relievers like acetaminophen or ibuprofen can help manage them while your body adjusts.
When a Headache Signals Something Else
In rare cases, a headache while taking Lexapro can point to something more serious than a routine adjustment side effect. Two conditions are worth knowing about.
Serotonin Syndrome
If your headache comes with a high temperature, agitation, confusion, trembling, or twitching, this could indicate serotonin syndrome, a potentially dangerous condition caused by too much serotonin activity. It’s most likely when Lexapro is combined with other medications that also raise serotonin, such as certain migraine drugs, other antidepressants, or even some supplements like St. John’s wort. Serotonin syndrome requires immediate medical attention.
Low Sodium Levels
SSRIs like Lexapro can, in some cases, cause the body to retain too much water relative to sodium, a condition called hyponatremia. Severe headache is one of its symptoms, along with confusion, nausea, and fatigue. The risk is highest in older adults and people taking diuretics (water pills). Research reviews have found that older age increases the odds of SSRI-related low sodium by roughly six-fold, and concurrent diuretic use raises it by eleven to thirteen-fold. If you fall into either category and develop persistent or worsening headaches, a simple blood test can check your sodium levels.