Complementary Versus Alternative Care: Why the Difference Matters

Complementary vs. Alternative Care in Plain Language

The National Institutes of Health (NIH) uses these two words for different things. A non-mainstream approach (one not typically part of conventional medical care) used together with conventional medicine is called complementary. One used in place of conventional medicine is called alternative. That small difference, “with” versus “instead of,” changes what you should ask and who should know about it.

Conventional care is the usual medical care most people know. NIH's National Center for Complementary and Integrative Health (NCCIH) gives medication, physical rehabilitation, and psychotherapy as examples. This guide explains the terms, corrects common mix-ups, shows what the evidence can and cannot tell you, and ends with a worksheet you can fill in before a health visit.

By the Integrative Health Evidence Guide Team. Last updated: September 23, 2026.

Safety Basics Before You Read On

• If you have signs of an emergency, such as trouble breathing, chest pain, or sudden weakness, call your local emergency number right away.
• Decisions about changing a prescribed medicine belong in a conversation with the clinician who prescribed it.
• NCCIH encourages you to discuss any decisions about treatment or care with your health care providers.

What the Main Terms Mean

NCCIH says these terms are still evolving. The descriptions below are how NIH currently defines them.

• Complementary: a non-mainstream approach used together with conventional medicine.
• Alternative: a non-mainstream approach used in place of conventional medicine.
• Integrative health: conventional and complementary approaches brought together in a coordinated way, with a focus on the whole person instead of one organ system.
• Whole person health: helping people improve and restore health across connected areas: biological, behavioral, social, and environmental.

NCCIH also notes that most people who use non-mainstream approaches also use conventional health care. It says the term “functional medicine” sometimes describes something similar to integrative health, but it can also describe an approach closer to naturopathy. NCCIH describes naturopathy as a medical system that evolved from a mix of traditional practices and health care approaches popular in Europe during the 19th century. When you hear the term “functional medicine,” ask what the person using it means by it.

Myths Versus Reality

Each item below pairs a common belief with what the two NCCIH sources say.

• Myth: Complementary and alternative mean the same thing.
  • Reality: People often use them interchangeably, but NIH treats them as different ideas. Complementary means “together with” conventional care. Alternative means “in place of” it.
• Myth: People who use these approaches have walked away from regular medical care.
  • Reality: NCCIH says most people who use non-mainstream approaches also use conventional health care.
• Myth: Integrative is just a softer word for alternative.
  • Reality: NCCIH describes integrative health as coordinated care among different providers and institutions, combining conventional and complementary approaches.
• Myth: “Functional medicine” always means the same thing as integrative health.
  • Reality: NCCIH says it may resemble integrative health, or it may look more like naturopathy. The label alone does not tell you.
• Myth: A product sold as an herb or supplement cannot affect my medicines.
  • Reality: NCCIH says more needs to be learned about the safety of these products and their interactions (ways they can affect each other) with medicines and other natural products. Its Herbs at a Glance series gives common names, what the science says, and possible side effects and cautions for individual herbs.
• Myth: If many people use an approach, it must be proven.
  • Reality: Popularity is not proof. NCCIH says researchers ran large, rigorous studies on a few dietary supplements, and the results often showed the products did not work for the conditions studied. Research on others is still in progress.

Evidence Limits to Keep in Mind

Verified facts from the sources

• NIH defines complementary as “together with” and alternative as “in place of” conventional medicine.
• In a 2012 national survey, more than 30 percent of adults and about 12 percent of children used health care approaches that are not typically part of conventional care. In the 2017 survey, yoga use among U.S. adults rose to 14.3 percent from 9.5 percent in 2012, and meditation use rose to 14.2 percent from 4.1 percent.
• The amount of research varies widely by practice. There are many studies on acupuncture, yoga, spinal manipulation, and meditation, and fewer on some other approaches.

Where the evidence is early or uncertain

• NCCIH describes research on integrative programs for cancer symptoms as early. Some studies have had promising results.
• NCCIH's wording for many approaches is cautious. It says things like “may help” or “appears to help,” not “will work.”
• Some survey figures are from 2012 and 2017, and the NCCIH definitions page lists its last update as April 2021. Numbers and wording may have changed since then.

Expert guidance

• NCCIH encourages people to discuss decisions about treatment or care with their health care providers. It also says that mentioning a therapy is not an endorsement.

What these sources cannot tell you

These sources cannot tell you whether a specific approach is safe or right for your situation. That takes a conversation with a qualified clinician who knows your health history and current medicines.

Conversation Worksheet: Prepare for Your Next Visit

Use these steps for any approach you are curious about. Write your answers down and bring the page with you.

1. Name it. Write the exact name of the approach, product, or practice, and where you first heard about it.
2. Sort it: with or instead of? Ask yourself whether you plan to use it together with your current care (complementary) or in place of part of it (alternative). If it is “instead of,” raise that first, and bring it to the clinician who manages that part of your care.
3. List everything you use now. Include prescriptions, over-the-counter medicines, vitamins, herbs, and other supplements. NCCIH's Herbs at a Glance page has fact sheets on individual herbs and also points readers to information on how herbs may interact with medicines. Read these before your visit and note any questions.
4. Read the public pages first. Many practices post their intake steps, testing, and payment rules online. This site's FAQ page covers topics like these for the practice described on this site. This guide does not verify the statements on that page. Use the questions in this worksheet to mark which claims you still need explained or backed by evidence.
5. Ask about the evidence.
   • What research supports this for my situation, and how strong is it?
   • What is still unknown?
6. Ask about safety.
   • What side effects or cautions apply to me?
   • Could this affect any medicine or supplement I take?
7. Ask about coordination.
   • Will my other clinicians be told about this?
   • Who is keeping track of the full picture?
8. Ask about practical details. Ask what it involves, how long it lasts, and what it costs. Also ask whether insurance rules apply.
9. Set a check-in. Ask how you and your clinician will know whether it is helping, and what would be a sign to pause and talk again.

Sources and Independence

• National Center for Complementary and Integrative Health (NIH): Complementary, Alternative, or Integrative Health: What's In a Name?
• National Center for Complementary and Integrative Health (NIH): Herbs at a Glance

This guide is general education from Integrative Health Evidence Guide.org Research Team. It does not evaluate, rank, or recommend any practice, provider, product, or service, including any described on this site's home page.

Educational Disclaimer

This article is for general information only. It is not medical advice, diagnosis, or treatment, and it does not replace the advice of your own health care provider. Do not start, stop, or change any treatment or medicine because of this article. Talk with a qualified clinician about your own situation. In an emergency, call your local emergency number.