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Complementary Health Approaches for Travelers

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What’s the Bottom Line?

How much do we know about complementary health approaches for travelers?

We know a fair amount about complementary health approaches for a few common travel-related health problems, including travelers’ diarrhea, jet lag, and altitude illness.

What do we know about the effectiveness of complementary health approaches for travelers?

Some complementary health approaches may be helpful for travel-related health problems, such as probiotics for travelers’ diarrhea and melatonin for jet lag, but most either haven’t been studied for travel-related problems or haven’t been shown to work.

What do we know about the safety of complementary health approaches for travelers?

The safety records are mixed for complementary health approaches for travel-related health concerns.

During your travels, you may develop a travel-related health problem, which could vary from something serious, like malaria, to just annoying, like mild diarrhea. Some travelers seek out complementary health approaches to ward off or treat health issues. The information about these approaches on consumer Web sites or in advertisements is often unsupported by research and misleading or false.

This fact sheet explains what studies tell us about herbal products, dietary supplements, and other complementary health approaches for travel-related ailments. A version of this fact sheet for health professionals is available online as part of the Centers for Disease Control and Prevention (CDC) Yellow Book. You can also find travel-related health information at the CDC’s Travelers’ Health Web page.


One of the most serious health concerns facing travelers to many countries is malaria, which you can get when bitten by Anopheles mosquitoes. Malaria causes flu-like symptoms and if left untreated can be deadly. You need prescription medication, protective clothing, and in some cases mosquito netting to protect yourself from malaria. There’s no evidence that the “natural remedies” you see advertised for preventing or treating malaria work.


The Zika virus, spread primarily by infected mosquitoes, isn’t dangerous to most people. In fact, many people infected with the Zika virus do not become sick, and those who do often have a mild illness. However, the virus can be passed from a pregnant woman to her fetus, and infection during pregnancy can cause certain serious birth defects. Pregnant women should not travel to areas where there is a Zika outbreak. Having unprotected sex with an infected partner may also pose a risk. For more information, see the CDC’s Web page on Zika and pregnancy.

There’s no vaccine or medicine for Zika. Some consumer Web sites and YouTube videos claim that herbs or other products, such as activated charcoal and diatomaceous earth, will protect against or treat the Zika virus. There’s no evidence that any complementary health products or practices can protect against the virus or treat an infection. Moreover, most dietary supplements haven’t been tested in pregnant women.

Travelers’ Diarrhea

One of the more common illnesses facing travelers is diarrhea; 30 to 70 percent of travelers, depending on where and when they travel, get it. You can’t escape travelers’ diarrhea by just avoiding certain foods or untreated water—you may need over-the-counter or prescription medications. Although most complementary health products don’t appear to help with travelers’ diarrhea, probiotics might be useful.

Altitude Illness

Altitude illness can occur when you travel to heights that you aren’t accustomed to, usually above 8,000 feet. Your body needs time to get used to the change in oxygen levels. Symptoms of altitude illness can be mild, such as dizziness, loss of appetite, or nausea, but can also become much more severe. There’s little, if any, evidence that dietary or herbal supplements can help prevent or treat altitude illness (also referred to as mountain sickness).

Motion Sickness

Children older than age 2 are the most likely to get motion sickness, but anyone can feel nauseous from the motion of traveling by boat, plane, train, or car. Medications may help prevent the nausea but may also have side effects.

Complementary health approaches have been studied or advertised for motion sickness but haven’t been shown to work well.

Nausea and Vomiting (“Morning Sickness”) in Pregnant Travelers

Feeling nauseous or even vomiting when pregnant isn’t unusual. For guidance on whether and when to seek medical care for this problem, visit this MedlinePlus Web page.

Following are complementary health approaches studied for morning sickness.

Jet Lag/Sleep

Jet lag occurs when you travel across time zones and your body’s biological clock hasn’t caught up yet. Jet lag can have different symptoms, such as feeling tired and irritable, having an upset stomach, and having difficulty falling asleep or waking up on time.

Colds and Flu

Your best protection against getting the flu is getting vaccinated. Everyone age 6 months and older should be vaccinated against the flu each year.

Here are some complementary health approaches that have been studied for avoiding colds and decreasing symptoms:

Insect Bites

Avoiding bites isn’t just for your comfort; bugs can spread a number of diseases.

Sun Exposure

Too much sun can cause skin cancer, the most common type of cancer in the United States. Being near the equator or at high elevation increases your exposure to the sun’s dangerous ultraviolet radiation. A few common medications, including some antibiotics, may make you more sensitive to the sun. You also need to watch for sun reflecting off of snow, sand, and water.


  • Homeopathic products called “nosodes” or “homeopathic immunizations” are promoted as substitutes for conventional immunizations. There’s no evidence that they work nor any scientific reason they should work.
  • It’s important that you are properly vaccinated against serious diseases before you travel. To find out what vaccines you may need, go to the Centers for Disease Control and Prevention Web page on vaccines for people traveling outside of the United States.

More to Consider

  • Dietary supplements may interact with your medications or pose risks if you have certain medical problems or are going to have surgery.
  • Many dietary supplements haven’t been tested in pregnant women, nursing mothers, or children.
  • Dietary supplements may contain ingredients not listed on the label, prescription drugs not allowed in dietary supplements, and other dangerous chemicals.
  • For more recommendations, see Using Dietary Supplements Wisely on the NCCIH Web site.
  • NCCIH has safety tips on supplements and mind and body practices for children and teens.
  • Take charge of your health—talk with your health care providers about any complementary health approaches you use. Together, you can make shared, well-informed decisions.

For More Information

NCCIH Clearinghouse

The NCCIH Clearinghouse provides information on NCCIH and complementary and integrative health approaches, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.

Toll-free in the U.S.: 1-888-644-6226

tty (for deaf and hard-of-hearing callers):



Email: (link sends e-mail)


A service of the National Library of Medicine, PubMed® contains publication information and (in most cases) brief summaries of articles from scientific and medical journals. For guidance from NCCIH on using PubMed, see How To Find Information About Complementary Health Approaches on PubMed.



To provide resources that help answer health questions, MedlinePlus (a service of the National Library of Medicine) brings together authoritative information from the National Institutes of Health as well as other Government agencies and health-related organizations.


U.S. Food and Drug Administration (FDA)

The FDA oversees the safety of many products, such as foods, medicines, dietary supplements, medical devices, and cosmetics. See its webpage on Dietary Supplements.

Toll-free in the U.S.: 1-888-463-6332


Federal Trade Commission (FTC)

The FTC is the Federal agency charged with protecting the public against unfair and deceptive business practices. A key area of its work is the regulation of advertising (except for prescription drugs and medical devices).

Toll-free in the U.S.: 1-877-382-4357


Key References

Altitude Sickness

Colds and Flu

Hepatitis C

Jet Lag/Sleep


  • Malaria. In: International Travel and Health 2012. Geneva, Switzerland: WHO Press; 2012:7.1-7.4.
  • World Health Organization. Global Malaria Programme. WHO Position Statement (June 2012): Effectiveness of Non-Pharmaceutical Forms of Artemisia annua L. Against Malaria. World Health Organization Web site. Accessed at /position_statement_herbal_remedy_artemisia_annua_l.pdf on May 3, 2016.

Motion Sickness



Travelers’ Diarrhea

Vaginal Infections/Urinary Tract Infections


NCCIH thanks Dr. John Williamson, NCCIH, for his technical expertise and review of this publication.

This publication is not copyrighted and is in the public domain. Duplication is encouraged.

NCCIH has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your health care provider(s). We encourage you to discuss any decisions about treatment or care with your health care provider. The mention of any product, service, or therapy is not an endorsement by NCCIH.

Last Updated: November 2017