Published 29 June 2026

Malaria Prevention for Travellers: Which Antimalarial Is Right for You?

Malaria kills more than 600,000 people every year, the overwhelming majority of them in sub-Saharan Africa. For international travellers visiting malaria-endemic regions, it is a serious and entirely preventable risk. The WHO reported 83 malaria-endemic countries globally in its World Malaria Report 2024. Yet malaria prevention medication is frequently misunderstood, taken incorrectly, started too late, or skipped altogether because travellers assume the risk is lower than it is or because they have heard that the medication has side effects.

This guide explains how the main antimalarial drugs work, what the differences are between them, how to choose the right one for your destination and circumstances, and what mosquito bite prevention measures you need to take alongside any medication. It covers the three drugs recommended by the CDC for most travellers to chloroquine-resistant malaria zones — atovaquone-proguanil (Malarone), doxycycline, and mefloquine — as well as the situations in which older drugs like chloroquine remain relevant and the newer option tafenoquine.

One important point before we start: no antimalarial drug is 100% effective. The most effective drugs, used correctly alongside consistent mosquito bite prevention, reduce your risk dramatically — but they do not eliminate it. Physical protection measures are not optional extras; they are essential components of a complete malaria prevention strategy.

Understanding Malaria: What You Are Protecting Against

Malaria is caused by Plasmodium parasites transmitted through the bite of an infected female Anopheles mosquito. Five species of Plasmodium cause human malaria: P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi. Of these, P. falciparum is the most dangerous — it accounts for the majority of severe malaria cases and deaths, and is the species most relevant to travellers visiting sub-Saharan Africa. P. falciparum accounts for approximately 97% of malaria cases worldwide and is almost universally resistant to chloroquine, the oldest and cheapest antimalarial, across Africa, most of Asia, and parts of South America.

P. vivax is less dangerous but important for travellers to South America and Southeast Asia, where it accounts for a significant proportion of cases. Unlike P. falciparum, P. vivax forms dormant liver stages (hypnozoites) that can reactivate weeks or months after the original infection, causing relapsing malaria. Standard antimalarials do not eliminate these liver stages, which is why travellers with prolonged exposure to P. vivax areas may need an additional drug (primaquine) at the end of their trip.

Symptoms of malaria — fever, chills, flu-like aching, headache, nausea — typically appear between seven and thirty days after the infective bite, though onset can be delayed for months in some cases. This is why fever in a returned traveller must always prompt immediate medical assessment with a disclosure of travel history. Malaria can deteriorate rapidly from what feels like ordinary flu to severe, life-threatening illness within twenty-four to forty-eight hours. Do not wait to see if a fever resolves on its own after travel to a malaria-endemic area. Sources: CDC Yellow Book — Malaria chapter, updated July 2025 | UpToDate — Prevention of Malaria in Travelers, updated July 2025

The Three Main Options for Most Travellers

Atovaquone-Proguanil (Malarone)

Atovaquone-proguanil, sold under the brand name Malarone and available as a generic, is a fixed-dose combination of two drugs that work together to kill malaria parasites at both the liver and blood stages of their lifecycle. It is effective against chloroquine-resistant P. falciparum and is the most commonly prescribed antimalarial for travellers visiting sub-Saharan Africa, Southeast Asia, and other high-resistance zones.

How to take it: Start one to two days before entering a malaria-endemic area. Take one adult tablet daily, with food or a milky drink, at the same time each day. Continue for seven days after leaving the endemic area. The short post-travel course — seven days compared to four weeks for doxycycline and mefloquine — is one of its most practical advantages for shorter trips.

Side effects: Atovaquone-proguanil is the best-tolerated antimalarial for most travellers. Serious side effects are uncommon. The most frequently reported issues are mild gastrointestinal complaints including nausea, stomach pain, and diarrhoea, which are usually reduced by taking the tablet with food. A Cochrane review of eight trials involving 4,240 participants found that atovaquone-proguanil users reported significantly fewer adverse effects of any kind — particularly neuropsychiatric events — compared to mefloquine users.

Who should not take it: It is not recommended for people with severe kidney disease (GFR below 30). It should be avoided during pregnancy because of limited safety data, and is not recommended for breastfeeding women whose infants weigh less than 5 kg. It can be used in children weighing 5 kg or more, though dosing below 11 kg constitutes off-label use in the US.

Cost: Atovaquone-proguanil is the most expensive of the three main options on a per-day basis. For a fourteen-day trip including pre- and post-travel doses, the drug course is manageable in cost terms. For trips of several months, the cumulative cost becomes significant. Generic versions are considerably cheaper than the branded Malarone and are equally effective. Sources: CDC — Choosing a Drug to Prevent Malaria, updated June 2025 | Cochrane — Drugs for Preventing Malaria in Travellers, PMC | NCBI StatPearls — Malaria Prophylaxis, updated March 2026

Doxycycline

Doxycycline is a broad-spectrum antibiotic that also works as an effective antimalarial at a daily dose of 100 mg. It is the cheapest of the three main options and is a good choice for last-minute travellers. It is also used by long-stay travellers for whom the cumulative cost of atovaquone-proguanil becomes prohibitive. A 2006 cost comparison found that generic doxycycline hyclate cost approximately USD $0.25 per dose compared to over USD $100 per dose equivalent for atovaquone-proguanil at then-current prices — though prices vary significantly by country and pharmacy.

How to take it: Start one to two days before entering a malaria-endemic area. Take 100 mg daily, with food and a full glass of water, at the same time each day. Continue for four weeks after leaving the malaria-endemic area. The four-week post-travel course is one of doxycycline's main practical drawbacks compared to atovaquone-proguanil.

Side effects: The most commonly reported side effects are gastrointestinal upset, photosensitivity (increased risk of sunburn), and in women, vaginal thrush. Taking doxycycline with food and a full glass of water significantly reduces gastrointestinal side effects. The photosensitivity risk means that travellers taking doxycycline should use high-factor sunscreen and avoid prolonged sun exposure — which can be a relevant consideration in tropical beach destinations. Doxycycline users had fewer reported neuropsychiatric events than mefloquine users in clinical trial data, and comparable side effect profiles to atovaquone-proguanil overall.

An underappreciated benefit: Doxycycline also protects against some additional infections that are relevant to travellers, including Rickettsial diseases (such as African tick bite fever, which is common among safari travellers) and leptospirosis. This makes it an attractive option for travellers who will be doing significant hiking, bush walking, or wading in fresh water.

Who should not take it: Doxycycline is contraindicated in pregnancy at all trimesters due to risk of effects on fetal bone and tooth development. It should not be used in children under eight years of age for the same reason — permanent dental discoloration is a documented risk. Women prone to vaginal thrush when taking antibiotics may prefer an alternative. Sources: CDC — Choosing a Drug to Prevent Malaria | PMC — Doxycycline for Malaria Chemoprophylaxis, CDC Expert Meeting | Minnesota Department of Health — Malaria Prophylaxis for Primary Care Providers, February 2025

Mefloquine (Lariam)

Mefloquine, sold under the brand name Lariam and available as a generic, is a weekly antimalarial that was widely prescribed for travellers throughout the 1990s and 2000s. Its once-weekly dosing schedule makes it attractive for travellers who find daily medication difficult to maintain, and it is the only antimalarial the CDC recommends for pregnant women travelling to chloroquine-resistant malaria zones across all three trimesters. However, mefloquine carries a black box warning from the FDA for neuropsychiatric side effects, and it is no longer the first-line choice for most travellers.

How to take it: Start one to two weeks before entering a malaria-endemic area — note that this requires more lead time than the other options. Take one tablet weekly, on the same day each week. Continue for four weeks after leaving the endemic area. The requirement to start two weeks before departure means mefloquine is not appropriate for last-minute travellers.

Side effects: Mefloquine's neuropsychiatric side effect profile is the reason it has fallen out of favour for most travellers. A head-to-head clinical trial published in Clinical Infectious Diseases found that 29% of mefloquine users experienced neuropsychiatric adverse events compared to 14% of atovaquone-proguanil users. The Cochrane review similarly found that compared to atovaquone-proguanil, mefloquine users had significantly more gastrointestinal adverse effects, overall adverse effects of any kind, and neuropsychiatric adverse effects including anxiety, strange or vivid dreams, insomnia, dizziness, and mood disturbance. Serious neuropsychiatric events including depression, psychosis, hallucinations, and seizures have been reported. The FDA's 2013 black box warning notes that neurological effects can persist long after the drug is discontinued.

The CDC and most travel medicine guidelines now recommend mefloquine only when the other options are contraindicated or not suitable, except in pregnancy and for certain specific situations. It remains effective and is still widely used; the side effect risk should be weighed against the individual traveller's circumstances with a travel health professional.

Who should not take it: Mefloquine is contraindicated for people with a history of psychiatric disorders including depression, anxiety disorder, schizophrenia, or other mental health conditions, and for those with a history of seizures. It is not recommended for people in jobs requiring fine motor coordination or spatial discrimination, such as pilots. It is not appropriate for last-minute travellers given the two-week lead-in requirement.

When mefloquine is still the right choice: For pregnant travellers who need antimalarial coverage in chloroquine-resistant areas, mefloquine remains the CDC's only recommended option across all three trimesters, as neither doxycycline nor atovaquone-proguanil has adequate safety data or is appropriate in pregnancy. For travellers who have used it before without side effects and are undertaking long trips where cost is a significant constraint, it remains a reasonable option. Sources: CDC Yellow Book — Malaria chapter | Wandr Health — Malarone vs Mefloquine comparison | New England Journal of Medicine — Malaria Prevention in Short-Term Travelers

Chloroquine: When It Is Still Relevant

Chloroquine was the mainstay of malaria prevention for decades but is now rarely used for most travel destinations because P. falciparum resistance to it is nearly universal across Africa, most of Asia, and parts of South America. It remains effective and appropriate for a small number of destinations where chloroquine-sensitive malaria predominates, including Mexico, Central America west of the Panama Canal, the Caribbean, parts of the Middle East, and limited areas of East Asia.

If your destination falls into this category, chloroquine is a safe, well-tolerated, and inexpensive option taken once weekly starting one to two weeks before travel and continued for four weeks after return. Your travel health professional or the CDC Yellow Book country tables will confirm whether chloroquine is appropriate for your specific itinerary. Sources: CDC — Choosing a Drug to Prevent Malaria | New England Journal of Medicine — Malaria Prevention in Short-Term Travelers

Tafenoquine: The Newer Option

Tafenoquine is a relatively new antimalarial approved by the FDA in 2018 for adults aged 18 and over. It is taken once daily for three days before travel, once weekly while in the endemic area, and once seven days after leaving — a dosing schedule that some travellers find more manageable than daily medication. It is active against both liver and blood stages of the parasite and is effective against P. vivax including hypnozoites, making it useful for travellers visiting regions where P. vivax relapsing malaria is a concern.

However, tafenoquine has important restrictions. It cannot be used in people with G6PD deficiency — a genetic condition affecting red blood cells — because it can cause potentially life-threatening haemolytic anaemia. A quantitative G6PD test is required before prescribing it. It is not approved for those under 18, and is not suitable during pregnancy or breastfeeding or for people with psychiatric conditions. It is not appropriate for everyone and should only be prescribed after a full clinical assessment. Sources: CDC Yellow Book — Malaria chapter | NCBI StatPearls — Malaria Prophylaxis

Which Drug for Which Destination?

The right antimalarial depends on where you are going and the drug resistance patterns in that area. The CDC publishes detailed, country-by-country guidance in its Yellow Book, updated as recently as April 2025, which lists recommended antimalarials for every malaria-endemic country. The following is a broad guide; always verify the specific recommendation for your destination.

Sub-Saharan Africa including Kenya, Tanzania, Uganda, and Rwanda, Ghana, Nigeria, and most of the continent: P. falciparum is the dominant species and is chloroquine-resistant throughout. Atovaquone-proguanil, doxycycline, or mefloquine are all recommended. Atovaquone-proguanil is the preferred first-line option for most travellers due to its tolerability and shorter post-travel course.

Southeast Asia including Thailand, Vietnam, Cambodia, Indonesia (including Bali), and the Philippines: P. falciparum is present and largely chloroquine-resistant. Critically, mefloquine-resistant P. falciparum has been confirmed specifically on the borders of Thailand with Myanmar and Cambodia, in western Cambodia, and in parts of southern Vietnam and Laos. In these areas, only atovaquone-proguanil or doxycycline should be used — mefloquine is not appropriate. This is an important exception that highlights why destination-specific guidance matters.

South and Central America including Brazil, Peru, Colombia, Ecuador, and Bolivia: A mix of P. falciparum and P. vivax. Chloroquine resistance is present. Atovaquone-proguanil, doxycycline, or mefloquine are recommended for most areas with significant transmission risk.

The Indian subcontinent including India, Bangladesh, Pakistan, and Nepal: P. falciparum and P. vivax both present. Atovaquone-proguanil, doxycycline, or mefloquine depending on the specific region. Sources: CDC Yellow Book — Yellow Fever Vaccine and Malaria Prevention Information by Country, April 2025

Mosquito Bite Prevention: Non-Negotiable Alongside Any Drug

Antimalarial medication is not a substitute for physical mosquito bite prevention — it is a complement to it. No drug is 100% effective. The Anopheles mosquitoes that transmit malaria bite primarily between dusk and dawn, which means evenings and nights are the highest-risk periods. The following measures should be practised consistently throughout your stay in any malaria-endemic area.

Use a DEET-based repellent on all exposed skin. A concentration of 20–30% provides effective protection and is safe for adults and children over two months of age. Apply after sunscreen, not before, and reapply every four to six hours or after swimming or sweating. Picaridin (also called icaridin) is an effective alternative to DEET with a less oily feel.

Sleep under an insecticide-treated mosquito net. Most established safari camps and lodges provide these; confirm with your operator before departure. If you are staying in budget accommodation or camping, bring your own. Permethrin-treated nets provide additional protection against mosquitoes that manage to land on the net.

Wear long-sleeved shirts and long trousers after dusk. Light-coloured clothing is preferable as mosquitoes are more attracted to dark colours. Treat outdoor clothing with permethrin spray for additional protection.

Stay in air-conditioned accommodation where possible. Screened windows and doors significantly reduce exposure. Sources: CDC — Malaria Travelers, Mosquito Avoidance

Special Situations

Pregnancy: Malaria poses serious risks in pregnancy including premature birth, spontaneous abortion, and stillbirth. The WHO and CDC both advise that pregnant women avoid travel to malaria-endemic areas if possible. If travel is unavoidable, mefloquine is the only CDC-recommended option for chloroquine-resistant areas across all three trimesters. Doxycycline is contraindicated throughout pregnancy. Atovaquone-proguanil is not recommended due to insufficient safety data, though it may be considered in certain situations after a careful risk-benefit discussion.

Children: All children travelling to malaria-endemic areas should be prescribed appropriate prophylaxis. Atovaquone-proguanil can be used in children weighing 5 kg or more. Mefloquine is safe for infants of any weight. Doxycycline should not be used in children under eight years of age. Paediatric dosing is weight-based and must be calculated precisely — do not give children adult doses. Overdose of antimalarials, particularly chloroquine, can be fatal in children.

Long-stay travellers: For trips exceeding three to four months, the cumulative cost of atovaquone-proguanil becomes significant. Doxycycline or mefloquine may be more practical for cost reasons. Adherence to daily or weekly medication over many months can also be challenging; this should be discussed with a travel health professional who can advise on the most sustainable regimen.

Diving: Mefloquine and doxycycline are generally considered compatible with scuba diving, though some dive medicine organisations recommend atovaquone-proguanil as the preferred option given that mefloquine's potential neuropsychiatric effects are particularly undesirable underwater. Discuss this with your travel health clinic.

What to Do If You Think You Have Malaria

If you develop fever, flu-like symptoms, chills, or unexplained illness during travel in a malaria-endemic region or within three months of return, seek medical attention immediately. Tell the doctor exactly where you travelled and for how long. Malaria is diagnosed by blood test — a clinical diagnosis without testing is not adequate. If you are in a remote area where medical care is not readily accessible, your travel health professional may have prescribed a stand-by emergency treatment kit before departure; use it only as directed and still seek medical care as soon as possible.

The earlier malaria is diagnosed and treated, the less severe it will be. Do not take a watch-and-wait approach to fever after travel to a malaria-endemic area.

The Countries That Need Antimalarials

Use the Travel Vaccine Map to check the malaria risk level for any destination. Countries showing a malaria risk of "widespread" or "regional" in our database require a conversation with your travel health professional about prophylaxis. Key high-risk destinations include Kenya, Tanzania, Uganda, Ghana, Nigeria, Zambia, Mozambique, Zimbabwe, India, Indonesia, Myanmar, Laos, Papua New Guinea, Brazil, Peru, and Colombia, among many others.

See also our destination-specific guides: Safari Health Prep for East Africa, Thailand Vaccine Guide, and South America Travel Health.

Sources

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This article is for informational purposes only and does not constitute medical advice. Always consult a qualified travel health professional or GP before travel.