Lexapro (escitalopram) is a prescription antidepressant used primarily to treat two conditions: major depressive disorder and generalized anxiety disorder. It belongs to a class of medications called SSRIs, or selective serotonin reuptake inhibitors, and is one of the most commonly prescribed antidepressants in the United States.
Approved Uses for Lexapro
The FDA has approved Lexapro for two specific conditions. The first is major depressive disorder (MDD) in adults and adolescents 12 years and older. The second is generalized anxiety disorder (GAD) in adults and children 7 years and older. These are the conditions Lexapro has been formally studied and proven effective for in clinical trials.
Beyond these official approvals, doctors frequently prescribe Lexapro “off-label” for other conditions that also involve disrupted serotonin signaling. These include social anxiety disorder, obsessive-compulsive disorder, panic disorder, PTSD, premenstrual dysphoric disorder, and hot flashes related to menopause. Off-label prescribing is legal and common when a doctor believes the medication will help based on clinical evidence or related research.
How Lexapro Works in the Brain
Your brain cells communicate using chemical messengers called neurotransmitters. Serotonin is one of these messengers, and it plays a major role in regulating mood, sleep, and anxiety. Normally, after serotonin delivers its signal between brain cells, it gets reabsorbed by the sending cell in a process called reuptake. Lexapro blocks this reuptake, which leaves more serotonin available in the gaps between brain cells. With more serotonin circulating, mood and anxiety signals can function more effectively.
This mechanism is why the drug takes time to work. It’s not like a painkiller that acts within an hour. The brain needs to gradually adjust to having more serotonin available before symptoms improve.
How Long It Takes to Work
Some early improvements, particularly in sleep, energy, and appetite, can show up within the first one to two weeks. But the full antidepressant and anti-anxiety effects typically take four to six weeks to develop. This is one of the most important things to know if you’re starting Lexapro: feeling no different after a week or two doesn’t mean it isn’t working. The brain needs time to recalibrate.
The standard starting dose for both depression and anxiety is 10 mg once daily. If needed, a prescriber may increase it to 20 mg after at least one week, though clinical trials found that 20 mg didn’t consistently outperform 10 mg for depression. The drug has a long half-life of about 27 to 33 hours, which means it stays active in your system for over a day and only needs to be taken once daily.
Common Side Effects
Most side effects tend to appear in the first few weeks and often lessen as your body adjusts. The most frequently reported ones include nausea, trouble sleeping or excessive sleepiness, fatigue, increased sweating, and sexual side effects like decreased libido or difficulty reaching orgasm. Sexual side effects are among the most persistent and are a common reason people consider switching medications.
Weight change is another concern people search for frequently. In clinical data, Lexapro was associated with modest weight gain of less than one pound over six months, which is relatively small. However, longer-term use (a year or more) of SSRIs as a class has been linked to more noticeable weight gain. The effect varies significantly from person to person.
Risks for Younger Patients
All antidepressants, including Lexapro, carry an FDA black box warning about increased risk of suicidal thoughts and behavior in children, adolescents, and young adults under 25, particularly in the first few months of treatment or when doses change. This doesn’t mean the medication causes suicide. It means that mood can shift unpredictably during the adjustment period, and close monitoring is essential. For most people, the risk of untreated depression is far greater than the risk posed by the medication itself.
What Happens If You Stop Taking It
Lexapro should not be stopped abruptly. Doing so can trigger discontinuation syndrome, a cluster of withdrawal-like symptoms that typically begin within two to four days of stopping. These can include flu-like symptoms (fatigue, headache, achiness, sweating), nausea, dizziness, burning or shock-like sensations sometimes described as “brain zaps,” and mood changes like irritability or heightened anxiety. Vivid dreams or nightmares are also common.
Lexapro carries a moderate risk for discontinuation syndrome compared to other antidepressants. Tapering the dose gradually under medical guidance, rather than stopping cold turkey, significantly reduces the chance and severity of these symptoms. The tapering schedule depends on how long you’ve been taking the medication and your current dose, but it typically involves small reductions over several weeks.