Lexapro (Escitalopram).
What It Does, Side Effects, and What to Expect.

Escitalopram -- sold under the brand name Lexapro -- is one of the most commonly prescribed psychiatric medications in the United States. If your provider has recommended it, or if you are trying to decide whether to try it, this guide explains what it actually does, what to expect in the first few weeks, and the side effects worth knowing about.

What Is Lexapro?

Lexapro (escitalopram) is a selective serotonin reuptake inhibitor, or SSRI. It works by increasing the availability of serotonin in the brain -- a neurotransmitter involved in mood regulation, sleep, anxiety, and many other functions. By blocking the reabsorption (reuptake) of serotonin, the medication keeps more of it active in the spaces between brain cells.

It has FDA approval for two conditions: major depressive disorder (in adults and adolescents 12 and older) and generalized anxiety disorder (in adults). It is also widely used off-label for panic disorder, social anxiety disorder, OCD, and PTSD.

Escitalopram is the refined version of citalopram (Celexa). It contains only the pharmacologically active component, which is why it tends to work at lower doses and with a somewhat cleaner side effect profile.

How Long Does It Take to Work?

This is the most common question -- and the answer requires patience.

• Week 1 to 2: Some people notice mild improvements in sleep or energy. Others notice nothing, or experience initial side effects (nausea, increased anxiety, headache). This early period is the hardest.
• Week 2 to 4: Most people begin to notice a gradual shift -- lower baseline anxiety, slightly better mood, more stable sleep. It rarely happens in a single moment; it tends to be a slow brightening.
• Week 4 to 6: A fuller response is typically visible by this point. This is usually when providers assess whether the dose is right or needs adjustment.
• Week 8 to 12: Full therapeutic effect. If Lexapro is going to work for you, you should have a clear sense of its benefit by this point.

Common Side Effects

Most side effects occur in the first 1 to 2 weeks and improve as your body adjusts. The most common include:

• Nausea -- especially in the first week; taking with food usually helps
• Headache -- typically temporary
• Increased anxiety or jitteriness -- counterintuitive but common at the start; usually settles within 2 weeks
• Fatigue or drowsiness -- often resolves; if persistent, timing the dose at bedtime may help
• Insomnia -- some people experience the opposite of fatigue; switching to morning dosing may help
• Dry mouth
• Increased sweating

Sexual Side Effects

This is the side effect that providers sometimes underdiscuss. SSRIs, including Lexapro, can affect sexual function in 30 to 40 percent of people -- including delayed orgasm, reduced libido, or difficulty reaching orgasm. This is not permanent, and it is not inevitable, but it is worth knowing about before you start.

If sexual side effects occur and are bothersome, there are options: dose adjustment, timing changes, adding a low-dose medication to counteract the effect, or switching to a medication with a different side effect profile. Do not suffer in silence -- bring it up with your prescriber.

Weight

Lexapro is generally considered weight-neutral or mildly weight-gaining. Most large studies show minimal average weight gain over the first year. However, individual responses vary, and some people do experience weight gain, particularly at higher doses or with longer-term use. This is worth monitoring and discussing with your provider. For more, see our post on antidepressants and weight gain.

What Dose Is Typical?

For adults, Lexapro is usually started at 5 mg or 10 mg daily. The typical therapeutic range is 10 to 20 mg. Dose increases are made gradually -- usually every 4 weeks -- based on how you respond and tolerate the medication. Going higher does not always mean going better; more is not always more with SSRIs.

Lexapro vs. Other SSRIs: How Is It Different?

All SSRIs work on serotonin, but they differ in their effects on other receptors, how long they stay in the body, their drug interaction profiles, and individual tolerability. No SSRI is universally "the best" -- the right choice depends on your history, other medications, and how you respond.

• Lexapro vs. Zoloft (sertraline): Both are widely used and have similar efficacy. Zoloft is often the first choice for anxiety and depression combined; Lexapro is often preferred for its simpler side effect profile. Zoloft tends to have more GI side effects early on. Both are generic and affordable.
• Lexapro vs. Prozac (fluoxetine): Prozac has a much longer half-life (stays in the body for weeks), which can be an advantage for people who miss doses but makes it harder to switch to certain other medications. Lexapro is smoother to start and stop.
• Lexapro vs. Paxil (paroxetine): Paxil tends to be more sedating and has more significant withdrawal symptoms. Most providers prefer Lexapro or Zoloft over Paxil for most patients.

How Long Will I Need to Take It?

For a first episode of depression or anxiety, current guidelines recommend continuing medication for at least 6 to 12 months after you feel better -- not just until symptoms improve. Stopping too early significantly increases the risk of relapse. For recurring conditions, longer-term maintenance treatment may be recommended. This should be a conversation with your prescriber, not a unilateral decision. See our post on how long to stay on antidepressants for more.