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

When you take mefloquine, a prescription antimalarial drug used to prevent and treat malaria. Also known as Lariam, it's one of the few pills still used in high-risk areas—but it comes with risks most people don’t talk about. Unlike simpler malaria pills like doxycycline or atovaquone-proguanil, mefloquine doesn’t just cause stomach upset. It can mess with your brain.

People who take mefloquine report neuropsychiatric side effects, a group of mental and nervous system reactions linked to the drug more often than with other antimalarials. These include severe anxiety, vivid nightmares, depression, panic attacks, and even hallucinations. The U.S. FDA issued a boxed warning in 2013 after reviewing hundreds of cases where people had lasting symptoms after stopping the drug. This isn’t rare—it happens in up to 1 in 10 users. If you’ve ever had anxiety, depression, seizures, or a history of mental illness, you should avoid mefloquine entirely. It’s not worth the gamble.

Physical side effects are just as real. Dizziness, loss of balance, ringing in the ears, and nausea hit about 1 in 3 people. Some report these symptoms for weeks or months after finishing the course. That’s not just "feeling off"—it’s your nervous system reacting. You might think you’re just tired from travel, but if you started mefloquine before your trip, it could be the cause. And unlike other drugs, there’s no quick fix if things go wrong. Stopping the pill doesn’t always stop the symptoms.

Who still uses mefloquine? Mostly travelers heading to parts of Southeast Asia or Africa where other drugs don’t work well. But even there, doctors are moving away from it. The CDC now recommends alternatives first. If your doctor pushes mefloquine, ask why. Is it cheaper? Is it the only option? Or are they just used to prescribing it? You deserve to know the full picture before swallowing a pill that could change how you feel for months.

What you’ll find below are real, practical posts about what happens when drugs like mefloquine go wrong—how to spot the signs, when to speak up, and what safer options exist. You’ll see how other people handled side effects, how doctors miss them, and how to protect yourself when traveling. This isn’t theory. It’s what people actually experienced—and what you need to know before you take your next pill.