Antidepressant Side Effects: What You Need to Know Before Starting Treatment

When you start an antidepressant, a medication used to treat depression and some anxiety disorders by balancing brain chemicals. Also known as antidepressive agents, these drugs can change how you feel—but they don’t always change how you feel good. Many people expect relief and get a headache, nausea, or worse instead. The truth? antidepressant side effects are real, common, and often underdiscussed. You won’t find them in the glossy ads, but you’ll find them in the quiet moments after your third week of taking pills and wondering why you feel more tired than ever.

Not all antidepressants act the same. SSRIs, a class of antidepressants that increase serotonin levels in the brain. Also known as selective serotonin reuptake inhibitors, they’re the most prescribed—drugs like fluoxetine, sertraline, and escitalopram. But they come with a shared set of side effects: dry mouth, weight gain, trouble sleeping, and sometimes a weird emotional numbness. Then there are SNRIs, tricyclics, and atypicals—each with their own fingerprint of reactions. Fluoxetine, a long-acting SSRI often used for depression and OCD. Also known as Prozac, it’s known for causing jitteriness early on, but many users report fewer sexual side effects than other SSRIs. That’s why comparing options matters. One person’s miracle drug is another’s nightmare.

Side effects aren’t always bad news—they’re often temporary. Nausea fades. Insomnia improves. But some stick around, and that’s when you need to talk to your doctor. Stopping cold turkey? Dangerous. Switching meds? Possible. Adjusting the dose? Often the answer. What you’re feeling isn’t weakness. It’s your body adapting. And you’re not alone. Thousands of people sit with these same questions every day: Is this normal? Will it get better? Should I keep going?

Below, you’ll find real comparisons and firsthand insights. We’ve pulled together guides that break down how fluoxetine stacks up against other SSRIs, what to expect when switching antidepressants, and how to spot when side effects are more than just annoying—they’re warning signs. No fluff. No marketing. Just what works, what doesn’t, and what to do next.