How Long Does It Take for Antidepressants to Work?

Most antidepressants don't provide instant relief of symptoms related to depression, anxiety, and other conditions for which they're prescribed. Rather, you must take them routinely and consistently for several weeks or even months before you notice changes. Here are a few guidelines on how long antidepressants take to work.

What Are Antidepressants?

Clinicians frequently prescribe antidepressants to help reduce symptoms of depression, anxiety, obsessive-compulsive disorder (OCD), social anxiety disorder (SAD), agoraphobia, and panic disorder. These medications work by affecting the brain's neurotransmitters—chemical messengers that are responsible for regulating sleep, mood, anxiety, motivation, and other functions and states.

Common Classes of Antidepressants and Examples

Antidepressant medicines generally fall into a few classes. The medications in each class are similar, but not identical.

• Selective serotonin reuptake inhibitors (SSRIs): Prozac (fluoxetine); Paxil and Pexeva (paroxetine); Zoloft (sertraline); Celexa (citalopram); Lexapro (escitalopram)
• Serotonin and norepinephrine reuptake inhibitors (SNRIs): Cymbalta (duloxetine); Effexor XR (venlafaxine); Pristiq (desvenlafaxine); Fetzima (levomilnacipran)
• Tricyclic antidepressants (TCAs)​: Tofranil (imipramine); Pamelor (nortriptyline); amitriptyline; doxepin; Norpramin (desipramine) 
• Monoamine oxidase inhibitors (MAOIs): Parnate (tranylcypromine); Nardil (phenelzine); Marplan (isocarboxazid); Emsam (selegiline)
• Atypical antidepressants: Trazodone; Remeron (mirtazapine); Trintellix (vortioxetine); Viibryd (vilazodone); Wellbutrin SR and Wellbutrin XL (bupropion); and more

Most are available in tablet form. Emsam is absorbed through a skin patch.

How Long Different Types of Antidepressants Take to Work

Antidepressants vary by type in the time they take to work, because each class works differently. In any case, you probably won't see significant improvement in your symptoms for several weeks after you begin your antidepressant dosing regimen.

Here are a few general guidelines on when you'll likely begin to see some relief from your symptoms, depending on which type of drug you are taking. Biomarkers may lag behind these more subjective responses.

• Selective serotonin reuptake inhibitors (SSRIs): About six weeks
• Serotonin and norepinephrine reuptake inhibitors (SNRIs): One to four weeks
• Tricyclic antidepressants (TCAs): Two to four weeks
• Monoamine oxidase inhibitors (MAOIs): As early as two weeks and up to six
  

What to Expect When Starting an Antidepressant

Once you start taking your antidepressant, you might feel a bit worse before you feel better. Researchers used to believe that the initial boost in energy an antidepressant sometimes provides explains the increased risk of harmful behaviors. However, newer research on SSRIs (the most commonly prescribed class) indicates that this occurs because antidepressants work on different chemicals in your body, and they each reach their optimum levels at different times.

When your antidepressant does start helping, don't stop taking it because you feel better. Stopping it suddenly might mean the return of your symptoms—along with some unpleasant, possibly dangerous, side effects.

Possible Side Effects of Antidepressants

Common side effects of antidepressants include:

• Sleep disturbances
• Headaches
• Fatigue
• Dizziness
• Lightheadedness
• Dry mouth
• Nervousness
• Increased sweating
• Sexual side effects
• Blurred vision
• Nausea

These are only some of the side effects you can face while taking an antidepressant. You may experience one or more of these, or none at all. Talk with your healthcare provider about any concerning symptoms.

It's important not to stop taking your antidepressant because it's causing side effects or seemingly not working; your body may just need time to adjust. To ease the transition, you might be prescribed a very low dose at first that is gradually increased. These side effects typically subside and become much more manageable over time.

Managing Your Condition While Waiting for Results

If you have an anxiety diagnosis, your doctor may initially prescribe a benzodiazepine (an anti-anxiety medication) along with your antidepressant. Benzodiazepines allow for a faster sense of symptom alleviation.

Benzodiazepines carry a risk for dependence and abuse, so your doctor may take you off this medication once the antidepressant reaches its full benefit.

Coping With Side Effects

If side effects are persistent and become difficult to manage, consult your doctor about the possibility of changing the dosage or medication to better fit your needs.

Considering a Change in Drug or Dosage

Your healthcare provider must balance any medication's potential benefits against its risks and side effects. If you and your clinician believe that you have had an adequate trial of antidepressant therapy without significant improvement or if you find the side effects intolerable, a medication change might be in order. Don't undertake a medication change without your doctor's supervision.

A Word From Verywell

Many people must try several different antidepressants before finding what works best—but most do find relief with the right antidepressant, especially when it's combined with psychotherapy. Always follow your healthcare provider's instructions regarding your antidepressant dosage regimen to maximize its benefits and minimize side effects.