Key takeaways:
Selective serotonin reuptake inhibitors (SSRIs) are medications commonly used to treat many mental health conditions, including depression. Common SSRI side effects include nausea, headache, and diarrhea. Sexual side effects, sleep changes, and weight changes can also happen.
Often, SSRI side effects will go away over time as your body adjusts to the medication. In the meantime, you can usually manage them at home.
More serious SSRI side effects include a greater risk of bleeding, suicidal thoughts, and changes in your heart rhythm. Serotonin syndrome can also occur. Get medical help right away if you experience any symptoms of serious side effects.
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Mental health conditions are common — roughly 1 in 5 adults in the U.S. live with one. And selective serotonin reuptake inhibitors (SSRIs) are a first-choice treatment option for many people. SSRIs include medications like fluoxetine (Prozac) and sertraline (Zoloft), among others. And while they can be a helpful mental-health treatment, there are also SSRI side effects you should be aware of.
Keep in mind that each SSRI is different and may cause other side effects not included in this list. Your healthcare provider or pharmacist can help answer any side effect questions you have about your particular SSRI.
1. Nausea
It’s common for SSRIs to cause nausea, especially when you first start taking them. Often, this side effect will improve over time as your body adjusts to the medication.
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Taking your SSRI with food can help lessen nausea. You can also talk to your healthcare provider about taking it at bedtime to lessen nausea during the day.
But if nausea persists or worsens, let your healthcare provider know. They may want to adjust your dose or try a different medication.
2. Headache
Headaches are another common SSRI side effect. But for most people, they’ll go away after you’ve been taking your SSRI for a couple of weeks.
In the meantime, talk to your healthcare provider about over-the-counter (OTC) treatment options, such as acetaminophen (Tylenol).
Good to know: Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (Advil) may not be the best choice to treat headaches because they can raise your risk of bleeding when taken with an SSRI — more on that later.
Hyponatremia
Rarely, SSRIs can cause low sodium levels (hyponatremia). This is more likely if you’re over 65 years old or you’re taking a diuretic. Hyponatremia can lead to dangerous swelling in the brain if it’s not treated.
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Headache is a common symptom of hyponatremia. So if you have a headache and you’re also feeling weak, confused, or faint, get medical help right away.
3. Diarrhea
SSRIs raise serotonin levels in your body. And more serotonin can lead to diarrhea in some people. While this side effect can be unpleasant, it often goes away on its own over time.
If it’s bothersome, talk to your healthcare provider about OTC diarrhea medications, such as loperamide (Imodium AD). And be sure to stay hydrated, since diarrhea can make dehydration more likely.
4. Anxiety
Although they’re often prescribed to treat anxiety, SSRIs can also cause or worsen anxiety symptoms in some people. This isn’t a common side effect, but it’s good to be aware of. Most of the time, anxiety symptoms appear in the first week or so of SSRI treatment.
If you start feeling anxious or jittery after starting an SSRI, be sure to let your healthcare provider know. They may want to wait and see if the symptoms improve over time. Or they may decide on a different dose or treatment option for you.
5. Sleep changes
Serotonin also plays an important role in your sleep cycle. Since SSRIs raise serotonin levels in your brain, they can also affect your sleep. This can range from insomnia and restlessness to nightmares and vivid dreams.
Your healthcare provider or pharmacist can advise you on the best time to take your SSRI to help manage how it affects your sleep patterns. Developing good sleep habits can also help.
Melatonin may also be an option if you’re having trouble sleeping. Just make sure it’s OK with your healthcare provider before taking it.
6. Weight changes
SSRIs may cause changes to your weight. Weight gain is more likely, but weight loss can also happen. And some SSRIs affect your weight more than others.
In some cases, being mindful of your eating and exercising habits can help lessen this side effect. But if you’re concerned about weight changes from an SSRI, talk to your healthcare provider.
7. Sexual problems
Sexual concerns, such as erectile dysfunction (ED), lowered sex drive, and orgasm difficulties, can also happen when you’re taking an SSRI. Like weight changes, each SSRI affects sexual function differently. And your response may not be the same as someone else’s.
In some cases, your symptoms may improve with time. But if there’s no improvement, your healthcare provider can help. They may add another medication to improve your sexual function, or they may switch you to a different SSRI or another type of medication altogether.
8. Suicidal thoughts
During the first few weeks or months of SSRI therapy (or after any dosing changes), there’s a greater risk of suicidal thoughts and behaviors. And the risk seems to be higher in people younger than 25 years old.
If you see a change in your moods or behavior, let your healthcare provider know right away. They’ll be able to make changes to your medication to manage this side effect safely.
If you or someone you know is having thoughts of suicide, you’re not alone, and help is available. Call the National Suicide Prevention Lifeline at 988, or text HOME to 741-741 to reach the Crisis Text Line.
9. Greater risk of bleeding
SSRIs may raise your risk of bleeding. This side effect is rare, but the risk is higher when SSRIs are combined with other medications that can raise your bleeding risk. A common example are NSAIDs, such as ibuprofen (Advil) and naproxen (Aleve).
If you spot unusual bruising or your gums bleed when you brush your teeth, let your healthcare provider know. More serious signs of bleeding, such as blood in your urine or stool, coughing up blood, or bleeding that doesn’t stop need medical attention right away.
10. Serotonin syndrome
Serotonin syndrome is a rare side effect of SSRIs, but it can be life-threatening. It’s caused when serotonin levels are too high. So the risk is higher when you take SSRIs with other medications that raise serotonin levels.
Symptoms of serotonin syndrome may include a fast heart rate, sweating, and tremors. But if it’s left untreated, confusion, uncontrolled movements, and a high fever can also occur. If you spot any of these symptoms, get medical care right away.
11. Heart rhythm changes
SSRIs can sometimes cause an abnormal heart rhythm. This isn’t a common side effect, but it’s a serious one. Be sure to let your healthcare provider know if you have a history of heart problems before starting an SSRI.
If you notice a change in your heartbeat while taking an SSRI, reach out to your healthcare provider. If you’re also feeling weak, lightheaded, or have chest pain, get medical help right away.
How long does it take for common SSRI side effects to go away?
Many common SSRI side effects are temporary and improve within a few weeks. They can often be managed at home in the meantime. But it’s still a good idea to let your healthcare provider know about them. They may want to keep a closer eye on your symptoms or adjust your dosage to help manage them.
If your side effects become worse or don’t go away over time, your provider may want to change your medication. Sometimes, a different SSRI will work better for you. Other times, a different type of medication may be better tolerated. But keep in mind that you shouldn’t stop taking an SSRI on your own. Doing so suddenly can cause unpleasant withdrawal symptoms. Your healthcare provider can help guide you to safely stop taking your SSRI if needed.
The bottom line
Nausea, headache, and diarrhea are common SSRI side effects. Sleep changes, weight changes, and sexual problems can also occur. Often, these side effects will go away over time as your body adjusts to the medication.
More serious SSRI side effects include an increased risk of bleeding, suicidal thoughts, and heart rhythm changes. Serotonin syndrome is also possible. Get medical care right away if you notice signs of a serious side effect.
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References
American Psychiatric Association. (2010). Practice guideline for the treatment of patients with major depressive disorder. Third edition.
American Psychological Association. (2019). APA clinical practice guideline for the treatment of depression across three age cohorts.
Bixby, A. L., et al. (2018). Clinical management of bleeding risk with antidepressants. Annals of Pharmacotherapy.
Camilleri, M. (2009). Serotonin in the gastrointestinal tract. Current Opinion in Endocrinology, Diabetes, and Obesity.
Carvalho, A. F., et al. (2016). The safety, tolerability and risks associated with the use of newer generation antidepressant drugs: A critical review of the literature. Psychotherapy and Psychosomatics.
Chu, A., et al. (2023). Selective serotonin reuptake inhibitors. StatPearls.
Endocrine Society. (2022). Brain hormones.
Grunebaum, M. F., et al. (2007). Safe use of SSRIs in young adults: How strong is evidence for new suicide warning? Current Psychiatry.
Harada, T., et al. (2014). A prospective naturalistic study of antidepressant-induced jitteriness/anxiety syndrome. Neuropsychiatric Disease and Treatment.
National Institute of Mental Health. (2023). Mental illness.
U.S. Food and Drug Administration. (2018). Suicidality in children and adolescents being treated with antidepressant medications.
