Start malaria tablets before you leave, not when you arrive

You need to begin taking malaria tablets one to three days before you enter a malaria risk area, depending on which tablet your doctor prescribes. Starting early lets the medication build up in your bloodstream so it can protect you from the moment mosquitoes might bite you. If you wait until you arrive at your destination, the tablets have not had time to work.

The exact timing depends on the specific tablet. Atovaquone-proguanil (Malarone) starts one day before travel. Chloroquine and mefloquine (Lariam) start one to two weeks before. Doxycycline starts one to two days before. Your doctor or travel clinic will tell you the right schedule for your prescription, and following it exactly matters—starting too late leaves you unprotected during your first days in a risk area, when mosquito exposure is often highest.

Key Takeaways

  • Start malaria tablets one to three days before entering a malaria risk area, not on arrival day, so the medication reaches protective levels in your blood.
  • Continue taking tablets every day while you are in the risk area, even if you do not feel sick and even if you use insect repellent and bed nets.
  • Keep taking tablets for four weeks after you leave the risk area—malaria can develop weeks later, and the final doses prevent parasites that entered your body near the end of your trip.
  • The exact start and stop dates depend on which tablet your doctor prescribes, so confirm the schedule before you travel.
  • Missing doses or stopping early is the most common reason malaria develops in travelers who took tablets.

Continue tablets every single day in the risk area

Once you arrive, take your tablet on the same day and time every day without skipping. Many travelers assume that insect repellent, long sleeves, and bed nets mean they can skip doses—they cannot. Malaria tablets work only if you take them consistently. A single missed dose can leave you unprotected, and malaria parasites can still enter your body even when you take precautions against mosquito bites.

Set a phone alarm or tie your tablet to a daily habit like breakfast or brushing your teeth. If you vomit within an hour of taking a tablet, take another dose. If you have severe diarrhea, the tablet may not absorb properly—contact a doctor or your travel clinic by phone to ask whether you need an extra dose. Traveling with a written list of your tablet name, dose, and schedule helps if you need to refill your prescription or explain what you are taking to a local doctor.

Keep taking tablets for four weeks after leaving the risk area

This is the step most travelers forget, and it is why malaria sometimes develops weeks after someone returns home. You must continue taking your tablet every day for four weeks after your last day in a malaria risk area. Parasites can be in your bloodstream without causing symptoms yet, and the final four weeks of tablets kill them before they multiply.

Mark your calendar on the day you leave the risk area, then count forward 28 days. That is your last tablet day. If you stop early, you risk malaria developing two to four weeks after you get home, when you may not connect the illness to your trip. Doctors sometimes miss malaria in travelers who do not mention their recent travel, so tell any doctor who treats you for fever in the months after your trip where you have been.

Adjust your schedule if you change your travel dates

If you leave the risk area earlier than planned, you still take tablets for four weeks after your new departure date. If you stay longer, you keep taking tablets every day through your extended stay, then count four more weeks from your actual last day in the risk area. Do not try to "make up" missed doses by taking extra tablets—take the next dose at the regular time and continue the schedule.

If you realize you have forgotten doses, contact your doctor or travel clinic as soon as possible. They can tell you whether you need to restart the full course or adjust your schedule. The longer the gap, the more important it is to get information rather than guess.

Different tablets have different schedules

Atovaquone-proguanil (Malarone) is taken once daily starting one day before travel and continuing for four weeks after leaving the risk area. Chloroquine is taken once weekly, starting one to two weeks before travel and continuing for four weeks after. Mefloquine (Lariam) is taken once weekly, starting one to two weeks before travel and continuing for four weeks after. Doxycycline is taken once daily, starting one to two days before travel and continuing for four weeks after.

Your doctor chooses based on which malaria parasites are in the area you are visiting, drug resistance patterns in that region, your medical history, and any other medications you take. Some tablets cannot be taken together with birth control, antibiotics, or other drugs. Confirm the exact schedule and any food or timing requirements before you travel—for example, doxycycline must be taken with a full glass of water and not right before bed, and some tablets are taken with food while others are not.

What to do if you cannot tolerate your tablet

Some people experience side effects from malaria tablets—nausea, vivid dreams, dizziness, or rash. If you have side effects, contact your doctor or travel clinic before you stop taking the tablet. They may suggest taking it with food, at a different time of day, or with another medication to ease the side effect. Stopping early because of side effects leaves you unprotected, which is riskier than managing the side effect.

If you truly cannot tolerate the tablet even with adjustments, your doctor may switch you to a different one—but this needs to happen before you travel, not after you arrive. If you are already in a risk area and cannot take your tablet, ask a local doctor or your country's embassy for information on alternatives or whether you should leave the area early.

Frequently Asked Questions

What if I forget a dose while I am traveling?

Take the missed dose as soon as you remember, unless it is almost time for your next dose. Then skip the missed dose and take the next one on schedule. Do not double up. If you miss more than one dose, contact a doctor or your travel clinic by phone or video call to ask whether you need to restart the course.

Can I stop taking tablets early if I feel fine?

No. Malaria can develop without symptoms for weeks, and you will not feel sick until parasites have multiplied in your blood. Stopping early is the most common reason travelers develop malaria after returning home. Take every dose for the full schedule, even if you feel completely healthy.

Do I need tablets if I am only in a city and not going to rural areas?

Malaria risk varies by location within a country. Some cities have little to no risk, while others have significant risk. Your doctor or travel clinic will tell you whether you need tablets based on your exact itinerary. Do not assume cities are safe—ask specifically about the neighborhoods and regions you plan to visit.

What if my prescription runs out before my four weeks after travel are finished?

Contact your doctor or travel clinic before you run out and ask for a refill. Bring your prescription with you when you travel, or have your doctor send a copy to a pharmacy near your destination. Some countries allow you to refill prescriptions at local pharmacies, but do not assume this—confirm before you travel.

Can I take malaria tablets if I am pregnant or breastfeeding?

Some tablets are safe in pregnancy and breastfeeding, and others are not. Tell your doctor when ready if you are pregnant, planning to become pregnant, or breastfeeding. Your doctor will choose a tablet that protects you and your baby, or may recommend avoiding travel to high-risk areas during pregnancy. Do not take any malaria tablet without discussing pregnancy status with your doctor first.