SSRI Side Effects: What You Need to Know About Common and Serious Reactions

When you start taking an SSRI, a class of antidepressants that increase serotonin levels in the brain to improve mood. Also known as selective serotonin reuptake inhibitors, these drugs are among the most prescribed for depression, anxiety, and OCD. But while they help millions, they don’t come without trade-offs. Many people expect relief from sadness or panic—but what they don’t always expect are the side effects that show up weeks or even days after starting.

Common SSRI side effects include nausea, drowsiness, dry mouth, and headaches. These usually fade within a couple of weeks as your body adjusts. But some effects stick around longer—and they’re harder to talk about. Sexual side effects like lowered libido, trouble getting aroused, or delayed orgasm affect up to half of users. That’s not rare. It’s routine. And it’s not something your doctor always brings up unless you ask. Then there’s serotonin syndrome, a rare but life-threatening reaction caused by too much serotonin, often from combining SSRIs with other drugs like tramadol or St. John’s wort. Symptoms? Shaking, high fever, fast heartbeat, confusion. If you feel this, go to the ER. Don’t wait.

Another hidden risk is SSRI withdrawal, a set of physical and emotional symptoms that can hit hard if you stop suddenly, even after taking the drug for just a few weeks. Dizziness, brain zaps, irritability, and flu-like feelings aren’t just "in your head." They’re real. That’s why tapering off slowly under medical supervision isn’t optional—it’s essential. And if you’re on an SSRI while pregnant, you should know about potential risks to newborns, like temporary breathing issues or jitteriness. It’s not a reason to avoid treatment, but it’s a reason to plan ahead.

You’ll find posts here that break down exactly how these side effects show up, which ones are most likely with which drugs, and what to do when they get worse. We cover how to manage sexual dysfunction without quitting the med, how to spot serotonin syndrome before it’s too late, and why some people feel worse before they feel better. No fluff. No jargon. Just what you need to know to stay safe and make smarter choices with your treatment.