A patient visits a functional medicine doctor.

Is Functional Medicine Legit?

The alternative approach promises to fill gaps missed by mainstream medicine. But does it deliver?

30-Second Takeaway

  • Similar to traditional physicians, functional medicine doctors look at factors like your genetics, lifestyle, and environment to construct a treatment plan that’s right for you and your health needs.
  • The big difference is that functional medicine examines your health from a holistic lens, which often entails undergoing experimental tests and alternative treatments—much of which isn’t covered by health insurance.
  • Though functional medicine lacks extensive research, recent studies show promising results for people living with chronic conditions.


bout 70 percent of Americans feel like traditional healthcare in the United States has failed them in some way, according to data from the American Academy of Physician Associates (AAPA) (1). One reason: Some 12 percent of respondents say there’s a lack of personalized care at their appointments. This may be why people are turning to practices like functional medicine, a form of alternative medicine that focuses on your individual genetic and lifestyle factors to treat (or prevent) disease at the source (2). But is functional medicine legit? And how does it differ from other types of medicine?

“Our current healthcare system offers little to combat chronic illnesses,” says functional medicine physician Amy Myers, M.D. “This has more people turning to the functional medicine approach for chronic disease.” For good reason: Research shows that functional medicine may be effective in treating diseases like diabetes and thyroid conditions like Hashimoto’s (3, 4). 

Still, critics of functional medicine say it’s expensive and lacks enough evidence to justify making a complete switch from mainstream medicine.

About the Expert:

Amy Myers, M.D., is a functional medicine physician and founder of her namesake supplement brand, Amy Myers, M.D. She specializes in treating autoimmune, thyroid, and digestive issues.

Danielle Kelvas, M.D., is a primary care physician and founder of DKMD Consulting. She specializes in weight loss, gut health, and nutrition. 

What Is Functional Medicine?

Functional medicine is a type of alternative medicine that was created by biochemist and writer Jeffrey Bland, Ph.D., through his for-profit entity, the Institute for Functional Medicine (5). Bland created functional medicine in 1991 in an effort to shift medicine from a drug-focused model to focusing on how your body’s systems work together as a way of treating chronic disease. 

So, what goes down during a functional medicine appointment?

Whether you’re seeking treatment for a chronic condition or just going in for your annual checkup, a functional medicine appointment will look different from a visit with your primary care physician, Myers suggests. For starters, it’ll last longer: Usually doctor visits last an average of 20 minutes in the United States, whereas a functional medicine session normally lasts around 90 minutes (6).

“Functional medicine doctors look at everything and strive to get a detailed medical history from preconception to the present,” Myers says. (For example, a traditional doctor might ask about your family history of cancer or heart disease. Whereas a functional medicine doctor will ask that plus, if your mom experienced complications during pregnancy like preeclampsia, gestational diabetes, or hypertension (7).) 

“They look for interactions among genetic, environmental, and lifestyle factors to determine the cause of your chronic symptoms—which can include anything from mold exposure to food sensitivities,” she adds.

A functional medicine treatment plan for autoimmune and/or chronic conditions may include taking supplements, following an anti-inflammatory diet, and starting hormone therapy. Of course, your treatment plan will depend on the chronic illnesses you’re at risk for, or are currently managing. No single functional medicine program looks the same, Myers notes.

Is Functional Medicine Legit?

The main criticism of functional medicine is that there aren’t many studies to support its approach. Some conventional physicians point to extreme overtesting (such as repeated blood testing and preventative scans) in functional medicine, which can be expensive at best and dangerous at worst (due to subsequent overtreatment) (8). 

Plus, some of the buzziest conditions treated in functional medicine, like “adrenal fatigue” and “leaky gut,” are mainly accepted as theories rather than diagnosable diseases (9, 10).

One vocal critic of functional medicine, the Science-Based Medicine initiative by the New England Skeptics Society, says that the practice is a “get out of jail free card” for physicians to justify any form of treatment outside what’s included in the standard of care (8). The standard of care is technically a legal term, however, in this context it describes medical treatments and practices that are universally recognized by both reputable medical organizations and healthcare professionals.

But many major medical organizations, like the Mayo and Cleveland Clinics, have launched their own functional medicine practices. These clinics meet a growing demand for integrative medicine and study the efficacy of the practice in treating chronic illness. And there are some emerging studies that show a quality of life benefit in managing chronic symptoms in certain functional medicine centers.

Findings from a 2019 study suggest that people living with chronic conditions (including diabetes, hypertension, and autoimmune disease) who were treated by a functional medicine doctor reported better quality of life after two years—compared to those who saw a traditional doctor for treatment (11). 

Specifically, participants who saw a functional medicine doctor reported lower levels of fatigue, pain, and gastrointestinal issues, and higher emotional well-being. (Note: The study did not detail the individual treatment plan for participants but suggested that functional medicine doctors recommended lifestyle and diet changes. Researchers also only followed people for one year, which is a substantially short period of time when it comes to monitoring chronic disease.)

And, a small-scale study in Cureus Journal of Medical Science found that people with Hashimoto’s disease—an autoimmune condition that impacts the thyroid—had lower inflammation after receiving functional medicine treatment compared to their baseline (4).

But what do traditional primary care physicians really think about functional medicine?

“Functional medicine providers are a critical part of the healthcare team,” says Danielle Kelvas, M.D. “I’ve even considered getting certified to become one myself.”

Kelvas says she understands why some people think functional medicine is “woo-woo,” as some people who practice functional medicine solely rely on less-studied (and non-medical) methods like Reiki, herbal medicine, and massage therapy. But other functional medicine doctors use evidence-based methods—like biomarker testing, hormone therapy, and more—as an integral part of their practice.

“Current medicine tends to just throw pills at symptoms now, while functional medicine doctors go to the root cause,” Kelvas. “So for example, in weight loss and obesity medicine, a functional medicine doctor will evaluate your lifestyle, sleeping and eating habits, stress, and everything else that can impact how your body stores or burns fat.”

Are functional medicine doctors M.D.s?

Some are, some aren’t. While M.D.s and D.O.s have to complete training from the Institute of Functional Medicine (IFM) to get certified as a functional practitioner, chiropractic and naturopathic doctors also can also get certified through the program. Ditto dietitians, physical therapists, occupational therapists, acupuncturists and physician assistants.

Sometimes practitioners without a traditional medicine degree (like acupuncturists or naturopaths) or an active license will call themselves “functional medicine doctors.” However, only M.D.s and D.O.s can write you a prescription—like hormone therapy or thyroid medication—as part of your treatment protocol. 

In other words, if you want a functional medicine doctor who prescribes medications along with holistic lifestyle and diet interventions, check their credentials to ensure they’re an M.D. or D.O. (Nurse practitioners and physician assistants can also write prescriptions in certain states.)

Who Is Functional Medicine Good For?

Don’t get it twisted—it’s not functional medicine vs. conventional medicine. Myers agrees that both types of medicine serve an important purpose in your health protocol. In other words, some people can benefit from having a balance of both.

But Myers believes functional medicine doctors may be better equipped to treat—and prevent—chronic and autoimmune conditions. 

Functional medicine benefits people who continue to have chronic symptoms even after getting conventional care, Myers says. “Functional medicine would help to identify the root cause and triggers through a lifestyle intervention.”

“Chronic health conditions affect about 50 percent of all American adults (12),” Myers says. “While genetics play a role in the development of chronic illness, new research proves what functional medicine practitioners have known for years that environment, diet, and lifestyle are a major part of the root cause.”

If you’re looking for a more personalized doctor’s visit, functional medicine isn’t your only option. Concierge medicine—a practice where patients pay an annual, out-of-pocket retainer fee to a traditional doctor who follows the standard of care—also offers lengthier, and more involved sessions.

Is Functional Medicine Covered by Insurance?

Most insurance plans don’t cover alternative or holistic treatments (even if your doctor is a M.D. or a D.O.), which can make treatment at a functional medicine practice expensive.

Why? Some of the more complex or experimental treatments or tests (like biological age scans) that functional medicine providers may include in a treatment plan don’t have a diagnostic code, Myers suggests. 

Physicians submit diagnostic and treatment codes to classify what symptom or disease they’re treating. Your insurance company then uses these codes to determine your coverage.

“Some diagnostic tests like bloodwork and labs may be covered,” Myers notes. But there’s no code for a personalized diet, lifestyle, and supplement plan. 

How much does functional medicine cost?

A single 90-minute functional medicine session can cost anywhere from $300 to upwards of $1,000 depending on your location and provider (13). You may also have to pay out of pocket for meal plans (like ProLon if your practitioner suggests a fasting-mimicking diet), supplements, and exhaustive genetic tests that aren’t typically covered by insurance. 

“To make functional medicine more accessible, we need to change the perception of medicine as a whole,” Myers says. “We have to move away from the notion that prescribing pills will cure illness and instead focus on well-being.”