Does Lexapro Make You Tired? Understanding Fatigue and Energy Changes
Author:
Blossom Editorial
Aug 14, 2025
Lexapro (escitalopram) is a widely prescribed antidepressant that can cause drowsiness and fatigue in some people, while others may experience the opposite effect. Understanding how Lexapro affects energy levels, when tiredness typically occurs, and what you can do about it can help you better manage this common side effect. Fatigue affects approximately 5-10% of people taking Lexapro, making it important to know when this symptom is normal and when it might require intervention.
Key Takeaways
Lexapro can cause tiredness, especially during the first few weeks of treatment, with fatigue or drowsiness affecting up to 41% of users in some studies, though this usually improves over time.
Higher doses cause more fatigue - people taking 20mg daily experience about twice the rate of drowsiness compared to those on 10mg, so starting with lower doses may help reduce tiredness.
Simple changes can help - adjusting when you take Lexapro (morning vs. evening), staying active with light exercise, and working with your doctor on timing or dose changes can significantly reduce fatigue while keeping the mental health benefits.
Does Lexapro Cause Drowsiness?
Lexapro can indeed cause drowsiness and fatigue, though this side effect varies significantly from person to person. The medication affects serotonin levels in the brain, which can influence sleep-wake cycles and overall energy levels.
Research shows that the most frequently reported adverse effects of escitalopram include fatigue and somnolence, along with insomnia, sexual dysfunction, nausea, and increased sweating. The timing and severity of drowsiness often depend on individual factors like dosage, time of day you take the medication, and your personal sensitivity to serotonin changes.
How Common Is Fatigue with Lexapro?
Clinical studies indicate that fatigue and drowsiness occur as common side effects of Lexapro, with somnolence being reported more frequently at higher doses. In clinical trials, the 20mg daily group showed approximately twice the rate of somnolence compared to the 10mg group and placebo.
A study specifically examining older adults with generalized anxiety disorder found that fatigue or somnolence occurred in 41.1% of patients taking escitalopram, making it the most common adverse effect in this population.
Common energy-related side effects reported with Lexapro include:
Daytime drowsiness or sleepiness
Feeling tired despite adequate sleep
Reduced motivation or energy for activities
Difficulty concentrating due to mental fatigue
The good news is that for many people, these effects are temporary and improve as the body adjusts to the medication over 2-4 weeks.
When Does Lexapro-Related Tiredness Occur?
Understanding the timeline of when fatigue typically appears can help you prepare and manage this side effect effectively.
First Week of Treatment
Tiredness often begins within the first few days of starting Lexapro. This initial fatigue is usually the most pronounced and can feel overwhelming for some people.
During this period, you might experience:
Excessive sleepiness during the day
Feeling "drugged" or mentally foggy
Needing more sleep than usual
Difficulty staying alert during normal activities
Weeks 2-4: Adjustment Period
Most people notice that extreme tiredness begins to improve during the second and third weeks of treatment. Your body is adapting to the medication, and energy levels often start to normalize.
This adjustment phase typically involves:
Gradual improvement in daytime alertness
Better regulation of sleep-wake cycles
Reduced intensity of fatigue symptoms
Beginning to feel more like your normal energy levels
Long-term Use
For most people, significant tiredness resolves within 4-6 weeks of starting Lexapro. However, some individuals may continue to experience mild fatigue as a persistent side effect.
Long-term energy patterns may include:
Stable but slightly lower energy levels than pre-medication
Good overall function with occasional tired days
Energy levels that fluctuate with stress or other factors
Complete resolution of tiredness with normal energy
Why Does Lexapro Make Some People Tired?
Several mechanisms explain why Lexapro can cause fatigue, helping you understand what's happening in your brain and body.
Serotonin's Role in Sleep and Energy
Lexapro increases serotonin availability in the brain, and serotonin plays a complex role in regulating sleep and wakefulness. Higher serotonin levels can promote relaxation and sleepiness in some people, especially when first starting the medication.
Research using sleep studies has shown that escitalopram can impair sleep continuity when measured objectively, though subjective sleep quality ratings may not always reflect these changes. Serotonin also influences the production of melatonin, the hormone that regulates sleep cycles. Changes in this system can temporarily disrupt normal energy patterns.
Brain Chemistry Adjustment
When you start taking Lexapro, your brain begins adapting to higher serotonin levels. This adjustment period can temporarily affect various brain functions, including those that regulate alertness and energy.
The brain's adaptation process involves:
Receptor sensitivity changes
Neurotransmitter balance shifts
Sleep architecture modifications
Circadian rhythm adjustments
Individual Variations
People respond differently to Lexapro based on their unique brain chemistry, genetics, and other factors. Some individuals are naturally more sensitive to serotonin changes, making them more likely to experience tiredness.
Factors That Influence Lexapro-Related Fatigue
Several personal and treatment factors can affect whether you experience tiredness and how severe it might be.
Dosage and Timing
Higher doses of Lexapro are more likely to cause drowsiness. Clinical trial data shows that patients taking 20mg daily experienced approximately twice the rate of somnolence compared to those taking 10mg daily.
The time of day you take Lexapro also matters:
Morning doses may cause daytime drowsiness
Evening doses might improve nighttime sleep but could cause morning grogginess
Splitting doses (if recommended by your doctor) might reduce peak tiredness
Taking with food may affect absorption and side effects
Individual Sensitivity
Some people are naturally more sensitive to antidepressant side effects. Factors that may increase sensitivity include age, body weight, liver function, and genetic variations in drug metabolism.
Concurrent Medications
Other medications can interact with Lexapro to increase drowsiness. Combinations that commonly cause increased fatigue include sleep aids, anti-anxiety medications, pain relievers, and certain blood pressure medications.
Underlying Health Conditions
Certain medical conditions can make Lexapro-related fatigue more pronounced or longer-lasting. These include sleep disorders, thyroid problems, chronic fatigue syndrome, and other conditions that already affect energy levels.
Managing Lexapro-Related Tiredness
There are several strategies you can use to minimize fatigue while taking Lexapro, though any changes should be discussed with your healthcare provider.
Timing Adjustments
Working with your doctor to optimize when you take Lexapro can significantly impact tiredness:
Morning dosing may help if you experience:
Difficulty falling asleep at night
Morning grogginess from evening doses
Better tolerance of daytime drowsiness
Evening dosing may be better if you have:
Significant daytime fatigue with morning doses
Insomnia or anxiety that improves with sedation
Work or school commitments requiring daytime alertness
Lifestyle Modifications
Simple lifestyle changes can help counteract Lexapro-related fatigue while supporting overall mental health treatment.
Sleep hygiene improvements include:
Maintaining consistent sleep and wake times
Creating a relaxing bedtime routine
Limiting screen time before bed
Keeping the bedroom cool, dark, and quiet
Energy-supporting habits include:
Regular moderate exercise (with doctor approval)
Eating balanced meals at consistent times
Staying hydrated throughout the day
Getting natural sunlight exposure during the day
Gradual Dose Increases
If you're just starting Lexapro, your doctor might recommend beginning with a lower dose and gradually increasing it. This approach can help minimize initial side effects like fatigue while allowing your body to adjust more gradually.
When Tiredness Might Indicate a Problem
While some fatigue is normal when starting Lexapro, certain situations warrant medical attention to ensure your safety and treatment success.
Severe or Persistent Fatigue
Contact your healthcare provider if you experience extreme tiredness that significantly interferes with daily activities or doesn't improve after 4-6 weeks of treatment.
Warning signs include:
Inability to stay awake during normal daily activities
Fatigue so severe it prevents you from working or caring for yourself
No improvement in energy levels after 6-8 weeks
Worsening fatigue over time rather than improvement
Safety Concerns
Excessive drowsiness can pose safety risks, especially if you drive, operate machinery, or work in environments where alertness is crucial. Don't hesitate to discuss these concerns with your doctor.
Depression vs. Side Effects
Sometimes it can be difficult to distinguish between medication-related fatigue and symptoms of depression itself. Depression commonly causes fatigue, low energy, and motivation problems that might persist despite treatment.
Alternative Approaches and Solutions
If Lexapro-related tiredness becomes problematic, several options are available to help while maintaining effective treatment for depression or anxiety.
Dose Adjustments
Your doctor might recommend lowering your Lexapro dose if tiredness is severe and other strategies haven't helped. Sometimes a lower dose provides adequate symptom relief with fewer side effects.
Medication Timing Changes
Switching from morning to evening dosing, or vice versa, is often the first adjustment tried. Research suggests that timing changes can significantly impact sleep quality and daytime alertness without changing the medication's effectiveness.
Adding Supportive Treatments
In some cases, your healthcare provider might recommend additional treatments to address fatigue:
B-vitamin supplements (if deficient)
Iron supplements (if anemia is present)
Thyroid hormone testing and treatment if needed
Sleep study evaluation for underlying sleep disorders
Switching Medications
If tiredness persists despite various adjustments, switching to a different antidepressant might be necessary. Some SSRIs are more activating (energizing) than sedating, and other classes of antidepressants have different side effect profiles.
Medical Disclaimer
This article is for educational purposes only and does not constitute medical advice. The information provided should not replace consultation with a qualified healthcare provider. Individual responses to medications can vary significantly, and what applies to one person may not be safe for another.
Always consult with your doctor or pharmacist before making any decisions about medication changes, discontinuation, or interactions with other substances. If you're experiencing concerning symptoms or side effects, please seek professional help from a healthcare provider. In case of a medical emergency, contact your local emergency services immediately or call 911. For mental health emergencies, contact the National Suicide Prevention Lifeline at 988.
Important: This information is not a substitute for professional medical advice. Never stop taking prescribed medication or make changes to your treatment plan without consulting your healthcare provider first. Your safety and well-being are the top priorities.
This article is for informational purposes only and is not a substitute for professional medical advice. Always consult with a qualified healthcare provider before starting, stopping, or changing any medication.
