Lexapro vs Celexa

How they're similar

Escitalopram and citalopram are both selective serotonin reuptake inhibitors, usually shortened to SSRIs. Given how closely they are related, they share a long list of features.

• They work the same way, by slowing the reuptake of serotonin so more of it stays available between nerve cells. Reuptake is the normal process by which a cell reabsorbs the serotonin it has released.
• They share a similar set of side effects, including nausea and other stomach effects, sexual side effects, increased sweating, and changes in sleep.
• They follow the same timeline. Early side effects can show in the first week or two, while the fuller effect on mood and anxiety usually takes four to six weeks, sometimes up to eight.
• Both can briefly feel activating early on, so some people feel a little more jittery or wired in the first week or two before things settle.
• Both have a dose-related effect on the QT interval, a measure of the timing of the heart's electrical cycle.
• Both carry the antidepressant boxed warning about a possible increase in suicidal thoughts in people under 25, especially early in treatment.
• Both can cause discontinuation symptoms if stopped abruptly, so both need a gradual taper planned with a prescriber.
• Both come as tablets and as an oral solution, and both have been available as inexpensive generics for years.

How they differ

The differences here are unusually narrow, because escitalopram is the purified active form of citalopram. The table below sums up the core points, with more detail underneath.

The relationship is the heart of it. A citalopram molecule exists in two mirror-image forms, like a left hand and a right hand. Only one of those forms does the antidepressant work. Citalopram contains both. Escitalopram is that active form on its own, with the inactive mirror image removed. This is why the two are so similar, and it is also why the doses do not match one for one. About 10 mg of escitalopram is roughly comparable to about 20 mg of citalopram. A prescriber keeps that ratio in mind when starting either drug or switching between them, so the change is not as simple as keeping the same number.

The approved uses differ slightly. Escitalopram is FDA-approved for major depressive disorder, in adults and in adolescents aged 12 to 17, and for generalized anxiety disorder in adults. Citalopram is approved for major depressive disorder. Citalopram is still widely used for anxiety, but that use is off-label, meaning a use that evidence and practice support even though the label does not formally list it. For someone whose main concern is generalized anxiety, the formal approval is a small point in favor of escitalopram, though many people are treated successfully with either.

The heart rhythm point is where the practical difference is clearest. Both drugs have a dose-related effect on the QT interval, but citalopram carries firmer FDA dose limits because of it. For citalopram, the general maximum is 40 mg a day, and the maximum is 20 mg a day for adults over 60, for people with significant liver impairment, and for some others. For escitalopram, the usual maximum is 20 mg a day, lowered to 10 mg for adults over 65 and for people with significant liver impairment. The headline is the same caution, but the dose ceilings are defined more strictly for citalopram. That can matter for someone with certain heart conditions or someone taking other medicines that affect heart rhythm.

On tolerability, escitalopram is often regarded as slightly cleaner and better tolerated, with stomach effects that tend to be milder, and it is frequently the one chosen now. Citalopram remains widely used and well established. The difference is a tendency, not a rule, and many people do well on either.

Side effects compared

The everyday side effects of these two medications overlap closely, which is expected given how related they are. Both can cause nausea and other stomach effects, sexual side effects, increased sweating, fatigue, dizziness, and changes in sleep. With both, side effects tend to arrive before the benefit. The stomach-related ones often ease within the first couple of weeks, while sweating and sexual side effects tend to last as long as the medication is taken.

Both also have a dose-related effect on the QT interval. For citalopram, that comes with firmer FDA dose ceilings, and for both, the maximum dose is lower for older adults. Both can rarely cause a drop in blood sodium, more often in older adults, and both can add to bleeding risk alongside NSAIDs such as ibuprofen or naproxen, aspirin, or blood thinners. Neither should be combined with an MAOI antidepressant, and the two should not be taken together with each other, since they are so closely related. If a side effect is severe, or it is not improving after a few weeks, that is a conversation to have with a prescriber rather than a reason to stop on your own.

Sleep, weight, and sexual effects

For sleep, weight, and sexual effects, the two are broadly similar.

Both are roughly weight-neutral in the short term, and some people lose a little appetite early on. With long-term use, modest weight gain is possible for some people with either drug. Both can disturb sleep, and less often, both can make some people sleepier. Because the effect on sleep goes both ways, the time of day to take either drug is often chosen based on how it affects a given person. If it disturbs sleep, morning tends to suit better. If it causes drowsiness, the evening can work better.

Sexual side effects are common with both. They can include lower sex drive, delayed orgasm, and arousal or erection difficulties, and they tend to last as long as the medication is taken rather than fading like nausea does. These effects are worth raising with a prescriber, because there are real options, including lowering the dose, switching to a medication less likely to cause this, such as bupropion, or adding another medication to counter it.

Why a clinician might choose one over the other

Because the two are so close, the choice is minor, and it often turns on a few small points.

A clinician might choose escitalopram for the generalized anxiety approval, for a slightly cleaner side effect profile, and for dose limits that are a little less restrictive than citalopram's. For a younger adult with anxiety and no heart concerns, escitalopram is a common starting point. A clinician might choose citalopram as a perfectly reasonable, well-established option that has been used widely for years, and cost or formulary coverage can tip the balance, though both are inexpensive generics.

Heart rhythm is a real tiebreaker. For someone with a known QT concern, or someone taking other medicines that affect heart rhythm, the tighter dose limits on citalopram become part of the picture, and a prescriber weighs that directly. Prior response matters a great deal as well. Someone who has done well on one of these medications already has a strong reason to stay with it, and someone who had trouble with one is not guaranteed the same trouble with the other.

The bottom line

These are two of the most similar antidepressants there are, since escitalopram is the refined version of citalopram. Neither is clearly better. Escitalopram has the anxiety approval and a slightly cleaner profile, while citalopram is a well-established option with firmer heart-rhythm dose limits. The choice between them is small and individualized, and it is made with a prescriber. Trying one and switching to the other is a normal step, not a failure.

Common questions

Is Lexapro just a stronger version of Celexa? Not exactly. Lexapro is the purified active half of the citalopram molecule, not a higher-strength version. Because the inactive mirror image is removed, the doses are different. About 10 mg of escitalopram is roughly comparable to about 20 mg of citalopram. So the same effect is reached at a lower number, which is not the same as being stronger.

Can you switch from Celexa to Lexapro? Yes, and a prescriber sometimes does this, often when side effects are an issue or when the anxiety approval of escitalopram is relevant. Because the two are so closely related, the switch is usually straightforward, but the doses are not one for one, so it should still be planned with a prescriber rather than swapped on your own.

Which has fewer side effects? The two have very similar side effects. Escitalopram is often regarded as slightly cleaner, with milder stomach effects, but the difference is a tendency, not a rule. Many people tolerate citalopram well. Citalopram does carry firmer FDA dose limits because of its effect on heart rhythm.

Should I take Lexapro or Celexa in the morning or at night? Either can work. Both drugs affect sleep in both directions, making some people wakeful and others drowsy. The timing is usually chosen based on how the drug affects a given person. If it disturbs sleep, morning suits better. If it causes drowsiness, the evening can work better. The key is to take it at the same time each day.

Sources

This guide draws on current prescribing information and public health references. It is reviewed for clinical accuracy and updated as guidance changes.

1. U.S. Food and Drug Administration. Escitalopram prescribing information.
2. U.S. Food and Drug Administration. Citalopram prescribing information.
3. MedlinePlus, U.S. National Library of Medicine.
4. National Institute of Mental Health. Mental health medications.