Lasmiditan Side Effects: What You Need to Know Before Taking It

When you take lasmiditan, a migraine-specific medication designed to stop attacks without constricting blood vessels. Also known as Reyvow, it works differently than older drugs like triptans—making it useful for people who can’t take those due to heart issues. But like all meds, it comes with side effects you should know before using it.

The most common lasmiditan side effects, reported in clinical trials and real-world use are dizziness, fatigue, nausea, and feeling sleepy. About 1 in 5 people experience dizziness after taking it, and many say they feel unsteady or lightheaded for a few hours. That’s why doctors tell you not to drive or operate heavy machinery for at least 8 hours after your dose. Fatigue isn’t just being tired—it’s a deep, overwhelming tiredness that can last through the day. Nausea is usually mild, but some people need anti-nausea meds on hand. These aren’t rare quirks; they’re expected outcomes tied to how the drug interacts with serotonin receptors in the brain.

Less common but far more serious is the risk of serotonin syndrome, a potentially life-threatening reaction when too much serotonin builds up in the body. This happens mostly when lasmiditan is taken with other serotonin-boosting drugs like SSRIs, SNRIs, or even certain herbal supplements like St. John’s wort. Symptoms include rapid heartbeat, high fever, confusion, muscle rigidity, and seizures. If you’re on antidepressants, talk to your doctor before starting lasmiditan. It’s not a blanket no—but it’s a conversation you can’t skip. Also, if you’ve had a stroke, heart attack, or severe liver problems, this drug may not be safe for you at all.

What’s missing from most patient info is how individual factors change your risk. Age matters—older adults are more likely to feel dizzy or fall. Weight matters too—people under 130 pounds may feel stronger effects at standard doses. And if you’ve had bad reactions to other migraine drugs in the past, you might react differently to lasmiditan. It’s not one-size-fits-all. That’s why tracking how you feel after each dose helps your doctor adjust things down the road.

You’ll find real stories in the posts below—from people who got relief without heart risks, to others who had to stop because the dizziness was too much. Some discovered that taking it with food helped with nausea. Others learned that combining it with sleep hygiene made the fatigue easier to handle. There’s no single answer, but there are patterns. What works for one person might not work for you—and that’s okay. The goal isn’t to avoid side effects completely, but to manage them so the benefit outweighs the cost.