Hello, I’m Dr. John Dempster, ND

  “It is my sincere belief that YOU can achieve an optimal state of health and well-being.”

Dr. John Dempster, ND
The Dempster Clinic - Center for Functional Medicine


Hello, I’m Dr. John Dempster, ND

  “It is my sincere belief that YOU can achieve an optimal state of health and well-being.”

Dr. John Dempster, ND


Optimal Aging

Aging well is not merely about what we put on our skin, it ultimately begins from within. A Functional Medicine approach allows for tremendous insight and offers the tools to slow down the degenerative aging process by optimizing your biology, environment and genetics in a program custom designed for YOU! Learn more about how your body is aging and the important steps you can take to look and feel your best.

Chronic Fatigue

Are you tired of relying on stimulants just to make it through the day? We are all unique, thus the ‘one-size-fits-all’ approach to solving chronic fatigue does not benefit everyone. Get to the TRUE underlying root causes of your fatigue and start feeling the best you’ve ever felt!


Many of those with Autoimmune Disease are dealing with chronic levels of inflammation that are created through factors in their diet, environment, genetics, and even emotions.  There are many ways to identify and eliminate these triggers by using a Functional Medicine approach and initiating the body’s own healing response.


If you struggle with Irritable Bowel Syndrome, Inflammatory Bowel Disease, constipation, diarrhea, or simply feel ‘off’ in the stomach, please know that there are ways to relieve the pain and discomfort that you are experiencing. Uncovering the causes and triggers of these symptoms is critical in order to recover from these pesky and sometimes serious conditions.

Shop Online for Supplements

The Dempster Clinic acknowledges the importance of nutrients from a whole food diet, but also believes that the body needs supplementation to optimize your health and cellular rejuvenation. In most cases, the body has difficulty getting all of the nutrients it needs from diet alone due to the chemicals in our food and in our environment. These chemicals cause added stress that interfere with proper digestion and detoxification of harmful toxins that can cause chronic disease and weight gain.

Are You Ready To

Address Your Chronic Digestive Issues

In The Next 21 Days?


What is Intravenous Vitamin Therapy?

Intravenous Vitamin Therapy is the infusion of vitamins, minerals, amino acids, and other natural substances directly into the vein.  Bypassing the digestive system is the main advantage of IV nutrition.  When substances are given orally they must be processed through the stomach, liver, and intestines.  Many substances may be rendered inactive in the digestive tract, or may not be well absorbed due to poor intestinal function.  By directly administering nutrients to the bloodstream, therapeutic doses of nutrients in blood levels can be absorbed more efficiently.  It is important to note that each treatment is customized to the patient’s individual needs. Explore our IV Vitamin Treatments.

Intravenous Vitamin Therapy (IV Vitamin Therapy)


Dr. Dempster, ND Blog - Everyday Health Tips


Functional Medicine — The Unsung Hero of Healthcare?

A couple of months ago I saw 2 patients (let’s call them Michael and Mary), who presented with very different symptoms. Michael was a young man who had lost some weight and suspected that he had diabetes, as the disease ran in his family. Mary was a middle-aged woman who suffered from fatigue, blurred vision and frequent tingling in her hands. She said she worked too much and needed something that would boost her energy. After talking extensively with each patient and conducting a couple of tests we confirmed that both of them had diabetes. Diabetes is just one example

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Which Functional Medicine Lab Tests Are Right For You?

Patients are often overwhelmed navigating the complex world of medical lab tests. When a patient comes in, suffering from a ‘bouquet’ of symptoms, each specialist orders a bunch of tests, yet after spending a ton of money and time, the patient often goes home undiagnosed and frustrated.  I often tell my clients that diagnosing diseases, especially complex ones like those related to autoimmune conditions, hormonal disbalance and gut issues, requires a holistic approach, where interlinkages between different systems are also taken into account. Specialists usually end up looking at a narrow set of test results that are directly linked to

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Seasonal Affective Disorder (SAD) is not a rare disorder

Functional Medicine Toronto – Are You Affected by a Seasonal Affective Disorder?

As we move out of the gorgeous summer months and into the longer and darker days of winter ahead, many North Americans find themselves feeling a decline in mood, energy, motivation and overall vitality. Seasonal Affective Disorder (SAD) is not a rare disorder. SAD affects 1 in 3 North Americans while many more likely feel some symptoms of SAD without recognizing it. The medical definition of SAD is: symptoms of depression coinciding with seasons of shorter days and less sunlight. This is blamed on the so-called biological internal clocks, or circadian rhythm, and it is said that SAD sufferers are

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Critical Info On Mast Cell Activation Syndrome (MCAS)

I have written a lot about various autoimmune conditions where your body’s defense mechanism turns against you and becomes your own enemy. Today, I want to bring your attention to another immunological condition during which overactivation of mast cells leads to a disorder called mast cell activation syndrome (MCAS). This condition is often overlooked or misdiagnosed, so raising awareness about MCAS, its symptoms, diagnosing and possible treatment options is extremely important.  Let me begin by talking about the mast cells. Actually, mast cells are a type of white blood cell that are found throughout the body (including under the skin,

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