Complementary therapies are health practices used alongside conventional medicine, not as replacements for it. They range from acupuncture and yoga to herbal supplements and massage, and roughly 38% of U.S. adults use at least one form. The key word is “alongside”: these therapies are meant to work with standard medical care, filling gaps in areas like pain management, stress, and sleep.
Complementary vs. Alternative vs. Integrative
These three terms get used interchangeably, but they describe different relationships with conventional medicine. A complementary therapy is a non-mainstream approach used together with your regular medical treatment. An alternative therapy is one used in place of conventional medicine entirely. Integrative health takes it a step further by coordinating both conventional and complementary approaches into a single care plan, with providers communicating and collaborating to treat the whole person rather than isolated symptoms.
In practice, most people who try these therapies use them as complements. Someone undergoing cancer treatment might add acupuncture to manage nausea, or a person with chronic back pain might combine physical therapy with massage. Using an herbal remedy instead of a prescribed medication would be the alternative approach, which carries more risk because it bypasses treatments with stronger evidence behind them.
The Three Main Categories
The National Center for Complementary and Integrative Health (NCCIH) groups these therapies into three broad categories based on what they primarily involve: physical, psychological, and nutritional approaches. Many therapies overlap. Yoga, for instance, has both physical and psychological components. Mindful eating bridges the psychological and nutritional categories.
Physical Approaches
These involve hands-on techniques or body movement. Acupuncture works by stimulating specific points on the body, which can trigger the release of the body’s natural pain-relieving chemicals, improve local blood flow, and influence the nervous system. Massage relaxes muscles, improves circulation and lymphatic drainage, and supports joint recovery. Chiropractic care focuses on spinal alignment and musculoskeletal issues. Tai chi and certain styles of yoga also fall here, using slow, controlled movements to build strength, flexibility, and balance.
Psychological Approaches
Meditation, mindfulness, hypnosis, biofeedback, guided imagery, and creative therapies like art or music therapy all target the mental and emotional side of health. The evidence base for mindfulness in particular has grown substantially. A large analysis of more than 12,000 participants with diagnosed anxiety or depression found that mindfulness-based approaches worked as well as established treatments like cognitive behavioral therapy and antidepressant medications. Mindfulness practices have also shown meaningful results for blood pressure: a review of over 1,100 people with conditions like hypertension, diabetes, or cancer found that mindfulness-based stress reduction significantly lowered blood pressure. For sleep, mindfulness outperformed education-based treatments but was no better than cognitive behavioral therapy or exercise.
There’s also promising data on addiction. A review of 37 studies with over 3,500 participants found that mindfulness-based approaches significantly reduced cravings and were slightly more effective than other therapies at promoting abstinence from substance use.
Nutritional Approaches
This category covers herbal remedies, dietary supplements, probiotics, and special diets. Common supplements include vitamins (like vitamin D), minerals (like magnesium and calcium), botanicals (like echinacea and ginger), plant-based compounds (like curcumin from turmeric), amino acids, and probiotics. These products are widely available, but they occupy an unusual regulatory space.
How Supplements Are Regulated
Unlike prescription drugs, dietary supplements in the U.S. do not require FDA approval for safety or effectiveness before they reach store shelves. Companies can introduce products to the market without even notifying the FDA. The responsibility falls on the manufacturer to ensure their product meets safety standards. The FDA’s oversight primarily begins after a product is already being sold. Supplements must carry a Supplement Facts label listing ingredients, serving sizes, and amounts, and they must be identified on the front label as a “dietary supplement” or something similar, like “herbal supplement.”
This means quality and potency can vary between brands, and claims on the label may not be backed by rigorous testing. It’s a very different standard than what applies to prescription medications.
Safety Risks Worth Knowing
Complementary therapies are often perceived as inherently safe because they’re “natural,” but several carry real risks, particularly when combined with medications. Herbal supplements are the biggest concern because they can interact with drugs in ways that either amplify side effects or reduce a medication’s effectiveness.
Some well-documented interactions:
- Ginkgo biloba taken with the blood thinner warfarin increases the risk of major bleeding.
- Goldenseal can reduce levels of the diabetes drug metformin by about 25%, potentially enough to interfere with blood sugar control.
- Green tea in high doses can lower blood levels of certain blood pressure and cholesterol medications, reducing their effectiveness.
- St. John’s wort is one of the highest-risk supplements for drug interactions. It interferes with immunosuppressants, blood thinners, oral contraceptives, heart medications, anti-anxiety drugs, and HIV treatments, among others.
- Chamomile may decrease the effectiveness of birth control pills.
Physical therapies also carry condition-specific risks. Certain yoga poses, for example, are unsafe for people with glaucoma. Chiropractic adjustments may not be appropriate for people with certain spinal conditions. The therapy itself might be low-risk in general but problematic for your specific situation.
Complementary Therapies in Cancer Care
Oncology is one area where complementary therapies have been widely adopted within mainstream medicine. People with cancer use them primarily to manage treatment side effects like nausea, pain, fatigue, and insomnia, as well as the anxiety and emotional distress that come with diagnosis and treatment. Acupuncture is commonly offered in cancer centers to address pain and chemotherapy-related nausea. Meditation, guided imagery, and yoga help with stress reduction and sleep. Tai chi, with its gentle movements and controlled breathing, is used to combat fatigue and improve quality of life during and after treatment.
These therapies are not used to treat the cancer itself. They’re used to make the experience of treatment more bearable and to support recovery.
Choosing a Practitioner
Licensing requirements for complementary health practitioners vary widely by state and by discipline. Chiropractors have the most standardized path: all 50 states require them to hold an accredited Doctor of Chiropractic degree and pass exams administered by the National Board of Chiropractic Examiners, state-specific exams, or both. Acupuncturists in most states must be certified by the National Certification Commission for Acupuncture and Oriental Medicine. Massage therapists can pursue certification through the National Certification Board for Therapeutic Massage and Bodywork, though state requirements differ.
When evaluating a practitioner, look into their education, training, and credentials. Ask whether they’re willing to coordinate with your other healthcare providers, because safe integrative care depends on communication between everyone involved in your treatment. Be upfront about all your health conditions, since what’s safe for one person may not be safe for another. And check with your insurance before assuming coverage. Plans vary enormously in which complementary approaches they’ll pay for, and many impose restrictions even on covered services.
The most important step is transparency in all directions: tell your complementary practitioner about your conventional treatments, and tell your doctor about any complementary therapies, supplements, or herbal products you’re using. That simple exchange of information is what prevents dangerous interactions and keeps your care coordinated.