Mefloquine: What It Is, How It's Used, and What You Need to Know

When traveling to areas where malaria is common, mefloquine, a synthetic quinoline derivative used to prevent and treat malaria infections. Also known as Lariam, it is one of the few oral medications that can stop malaria before it takes hold in your body. Unlike some other antimalarials, mefloquine isn’t just for treatment—it’s often taken weekly, starting before you even leave home, to build up protection. It’s not a simple pill you pop when you feel sick; it’s a preventive tool, designed to block the parasite from multiplying in your blood.

But mefloquine isn’t for everyone. It’s linked to serious side effects like dizziness, anxiety, vivid dreams, and in rare cases, long-term neurological issues. People with a history of depression, seizures, or heart rhythm problems are usually told to avoid it. The CDC and WHO still list it as an option for travelers to parts of Africa and Southeast Asia, but many doctors now prefer alternatives like atovaquone-proguanil or doxycycline because they’re better tolerated. If you’ve ever heard someone say, "I took mefloquine and couldn’t sleep for weeks," that’s not an urban myth—it’s a documented reaction.

What you won’t find in most travel clinics is a full picture of how mefloquine stacks up against newer drugs. Some posts here dig into how hydroxychloroquine, another antimalarial once widely used for autoimmune conditions and malaria. Also known as Hsquin, it has largely been replaced by safer options in malaria treatment, and why that shift happened. Others compare how bioequivalence testing, the process that proves generic versions of drugs work the same as brand-name ones applies to mefloquine generics sold overseas. And if you’re wondering why some countries stopped prescribing it altogether, there’s a post on how medication side effects, adverse reactions reported by patients that can change clinical guidelines led to warnings from health agencies worldwide.

There’s no single answer to whether mefloquine is right for you. It depends on your destination, your medical history, and how your body reacts to chemicals. Some people take it without issue. Others can’t even tolerate the first dose. The goal here isn’t to push you toward or away from it—it’s to give you the facts, the risks, and the context so you can talk to your doctor with real understanding. Below, you’ll find real-world stories, comparisons with other antimalarials, and breakdowns of the science behind why this drug still exists—and why so many are moving on.