Dr. John Maher runs Valley Center Chiropractic and Holistic Care, where he's built a reputation well beyond his local community: GHP Magazine named his practice among the top 25 chiropractic clinics in the United States in 2017, and the International Association of Chiropractors has recognized him as a top chiropractor in Valley Center for demonstrating leadership and success in the field. Closer to home, he's been named best chiropractor in the Valley multiple years running, including 2023, 2024, and 2025. In this conversation with Mark Anthony, he broke down the technique at the center of his practice: nutritional response muscle testing, more formally known as applied kinesiology.
Maher's path into chiropractic started with a friend's family, not his own ambition. His best friend Dennis had a child and a spouse both dealing with asthma; a well-known chiropractor treated them successfully using techniques related to what Maher practices today, and Dennis decided to enroll in chiropractic college. Maher — who was already drawn to yoga and natural health while living in the Riverside, California area — began helping Dennis study, got hooked, and eventually took a demotion at his own job so he could work nights and attend chiropractic school during the day. He's used muscle testing with patients since 1980, refining it over decades, and has since trained other doctors in the technique across the United States and Canada.
Key Takeaways
- Nutritional response muscle testing (a form of applied kinesiology) checks how a muscle responds — strengthening or weakening — when a supplement, remedy, or stimulus is placed on or near the body, as a way of reading the nervous system's response.
- Dr. Maher demonstrated the concept with a handheld vibrating device: held several feet away it has no effect, but held about a foot from the head it weakens the tested muscle — an effect he attributes to the body's sensitivity to electromagnetic fields, which disappears once the patient is connected to a grounding (earthing) pad.
- He uses reflex points on the body, similar in concept to acupuncture points, to identify which organ systems are under stress before testing which supplements or remedies the body responds to.
- In his osteoporosis example, rather than defaulting to calcium carbonate and vitamin D, he tests different calcium forms, collagen sources, and hormone-precursor options — sometimes tracing weak hormone production back to chronic stress, a pattern he calls "cortisol steal."
- Maher argues muscle testing meets the definition of a scientific phenomenon — observable, measurable, repeatable, and predictable — even though the underlying mechanism isn't yet fully understood.
What Is Nutritional Response Muscle Testing?
Maher's explanation starts simply: a product is placed on or near a patient's body, and a muscle is gently tested. If the product is right for that person, the muscle holds strong; if it's wrong, it weakens. Most people call this muscle testing, but Maher was direct about what's actually being measured — "the truth is what we're testing is the nervous system," both consciously and unconsciously.
To demonstrate, he has patients lie down and raise an arm while he tests the muscle. He then holds a small vibrating device about three feet away — no change. Moved to roughly a foot from the patient's head, the same muscle weakens. Patients are often surprised, guessing it's the sound. So Maher steps on a grounding, or earthing, pad — connected to the ground wire of a standard outlet — while holding the patient, and repeats the test with the vibrator at the same distance. This time, no weakening, even though the patient hears the identical sound. His conclusion: the body is responding to the device's electromagnetic field, not the noise, and grounding blocks that response.
From there, Maher extends the idea to supplements and remedies generally. Everything, he argues, carries its own frequency — the same reason burning zinc produces one color and burning copper another. A supplement or homeopathic remedy has a frequency of its own, and in his framing, the nervous system can unconsciously recognize whether that frequency is a match for what a given tissue needs to heal.
"The nervous system is aware of things that you and your conscious mind are not."
— Dr. John MaherInside a Session: Reflex Points, Osteoporosis, and the Stress-Hormone Connection
Maher described testing reflex points on the body — conceptually similar to acupuncture points — tied to specific organs like the thyroid, pancreas, bladder, or ovaries. A weak reflex point over the ovaries, for example, points him toward supplements aimed at supporting ovarian function, which he said comes up often in cases of PMS.
He walked through a more detailed example using osteoporosis. The standard medical approach, he noted, has largely been unchanged since the 1970s: a low-cost form of calcium (calcium carbonate) plus a low dose of vitamin D. But bone, he explained, is mostly collagen — a protein framework that holds minerals like magnesium, phosphorus, and manganese in place — and there's no simple blood test that tells a doctor which form of calcium, or which collagen source, a specific patient actually needs. Rather than guess, he tests different options directly: various forms of calcium, collagen, or bone broth, checking which one the patient's body responds to.
The hormone side of a workup follows the same logic. If a patient may need more progesterone, Maher tests whether a precursor like wild yam or pregnenolone is appropriate — but he also looks upstream at why the body isn't producing enough on its own. Chronic stress, he explained, can push the body to prioritize cortisol production using the same raw material needed to build other hormones, a pattern he calls "cortisol steal." In those cases, the more useful move can be supporting the body's stress response first — with something like L-theanine, magnesium, or ginseng — rather than reaching straight for hormone supplementation.
Maher was candid that the underlying logic doesn't require him to know every answer in advance. "I don't need to know the answers," he said, describing the process as building a decision tree in real time — testing, getting a yes or no, and following the body's responses until he arrives at what a given patient needs.
Is Muscle Testing "Real" Science?
Maher anticipated the skepticism directly. His argument: a scientific phenomenon is one that is observable, measurable, repeatable, and predictable — not necessarily one that is fully understood. He compared it to gravity — accepted as real and predictable long before physicists could say definitively what it is. By that standard, he argued, muscle testing qualifies: the muscle visibly weakens or stays strong, the same product produces the same result on repeat testing, and the outcome can be predicted before the test is run.
He extended the same framework to emotional and cognitive states, describing his use of Emotional Freedom Technique alongside muscle testing — asking a patient to state something like "I love myself" and watching whether the muscle strengthens or weakens in response. He also recounted a classroom demonstration: a student was muscle-tested, then sent out of the room while classmates were asked first to think unkind thoughts about him, then loving ones. Maher described the student testing weak after the first round and unable to be weakened at all after the second — an anecdote he offered as illustrating how directly thought and emotion can show up in the same testing process he uses for supplements.
For patients on the fence, Maher described a low-cost introductory visit where he runs the same vibrator-and-grounding-pad demonstration in person, so people can watch their own muscle respond before deciding whether to pursue treatment further.
Who This Conversation Is For
If you've wondered why a treatment plan hasn't moved the needle, or you're curious what practitioners mean by "the body already knows the answer," this episode is a plain-language look at how one experienced chiropractor uses muscle testing to personalize nutrition, hormone support, and stress management — straight from a practitioner who has spent over four decades refining the technique.
