Episode 628: Can Ozempic Help MCAS and Chronic Lyme? Dr. Tania Dempsey's New Research | LIVE from ILADS
Tick Boot Camp
Could medications best known for weight loss and diabetes offer a new way to manage mast cell activation syndrome (MCAS), inflammation, and symptoms experienced by some patients with chronic Lyme disease?
In this LIVE from ILADS episode of the Tick Boot Camp Podcast, co-host Rich Johannesen reunites with Dr. Tania Dempsey, MD, a physician specializing in complex chronic illness, mast cell activation syndrome, and tick-borne diseases, for an exciting discussion about emerging research into GLP-1 medications and immune system dysfunction.
Recorded at the 2025 International Lyme and Associated Diseases Society (ILADS) Conference in San Antonio, Texas, the conversation centers on Dr. Dempsey's recently published research investigating GLP-1 receptor agonists—medications such as Ozempic, Wegovy, Mounjaro, and Zepbound—as potential treatments for patients with MCAS.
Dr. Dempsey discusses a 47-patient case series in which 87% of participants reportedly experienced a positive response to GLP-1-based treatment. She explains why these medications may have effects beyond blood sugar regulation and weight management, including potential influences on mast cell activity and inflammation.
The interview also explores how mast cell dysfunction may interact with other components of the immune system, why Dr. Dempsey questions relying exclusively on antibody testing when evaluating certain complex patients, and how emerging molecular diagnostic methods could influence the future of tick-borne disease care.
Throughout the conversation, Dr. Dempsey emphasizes the importance of individualized treatment, continuing research, and helping both patients and healthcare professionals better understand complicated chronic illnesses.
Could GLP-1 medications represent a new direction in MCAS research? And what might that mean for patients living with Lyme disease, Bartonella, and overlapping inflammatory symptoms?
This episode explores those questions while distinguishing promising early clinical observations from treatments that have been conclusively established through larger controlled studies.
Meet Dr. Tania Dempsey, MD: MCAS and Complex Chronic Illness
Dr. Tania Dempsey is a physician known for her clinical work with patients experiencing mast cell activation syndrome, Lyme disease, tick-borne infections, and other complex chronic conditions.
Her interests include the relationship between immune system dysfunction, inflammation, environmental exposures, and persistent symptoms.
Dr. Dempsey has become an increasingly prominent voice in discussions about MCAS and its potential relationship with other chronic illnesses.
During this interview, she shares how appearing on major podcasts, including Dave Asprey's podcast, has helped her reach a broader audience.
She explains that although she loves working directly with patients, her larger mission is to share information with healthcare professionals and patients around the world.
Dr. Dempsey also discusses her involvement with the International Lyme and Associated Diseases Society (ILADS).
At the time of this interview, she had served on the ILADS Board of Directors for two years and had recently been reelected for another two-year term.
She describes physician education, research, and public awareness as important priorities for her continued work with the organization.
For an in-depth discussion of her clinical interests, listen to her previous Tick Boot Camp appearance: Dr. Tania Dempsey on MCAS, Chronic Lyme Disease, GLP-1 Agonists, Biofilms, and Precision Medicine.
New Research: GLP-1 Medications for Mast Cell Activation Syndrome
One of the biggest developments Dr. Dempsey shares is her recently published research on GLP-1 receptor agonists and MCAS.
GLP-1 receptor agonists are medications primarily used for conditions such as type 2 diabetes and obesity.
Some of the medications discussed include:
Ozempic: Semaglutide
Wegovy: Semaglutide
Mounjaro: Tirzepatide
Zepbound: Tirzepatide
Semaglutide acts on GLP-1 receptors, while tirzepatide acts on both GLP-1 and GIP receptors.
Although these medications are widely associated with weight management, researchers are also investigating their broader metabolic and inflammatory effects.
Dr. Dempsey explains that her research explores whether these effects could benefit certain patients with mast cell activation syndrome.
She presented findings from the research at the ILADS conference and describes receiving enthusiastic feedback from other clinicians interested in the potential applications.
Importantly, GLP-1 medications are not established or FDA-approved treatments for MCAS. The findings discussed in this episode are preliminary and require further research to determine effectiveness, safety, appropriate patient selection, and dosing.
The 47-Patient GLP-1 and MCAS Case Series
Dr. Dempsey highlights findings from a published case series involving 47 patients.
According to her description:
The case series included 47 patients receiving GLP-1-based treatment.
Approximately 87% reportedly experienced a significant positive response.
Some patients reported improvements in joint pain.
Others experienced reductions in brain fog and additional symptoms.
Certain patients reported noticeable changes within hours of treatment.
Treatment approaches were individualized, including the use of low doses in some patients.
These observations have generated interest because MCAS can be challenging to manage, particularly in patients who report sensitivities to multiple medications or supplements.
Dr. Dempsey describes the results as especially encouraging for patients whose symptoms have persisted despite other interventions.
However, a case series does not establish that a medication caused the reported improvements.
Without a randomized control group, it is difficult to distinguish treatment effects from other influences, including natural symptom fluctuations, concurrent treatments, and selection bias.
The reported 87% response rate should therefore be understood as a finding from this particular patient group—not a predicted success rate for everyone with MCAS.
Larger, well-controlled clinical studies are needed.
What Is Mast Cell Activation Syndrome (MCAS)?
Rich asks Dr. Dempsey to explain MCAS in terms that patients without medical training can understand.
She begins by describing the normal function of mast cells.
Mast cells are immune cells that help the body respond to infections, allergens, and other potential threats.
When activated, they release substances called mediators, which participate in immune signaling and inflammation.
These mediators include histamine, cytokines, and other biologically active compounds.
Under normal circumstances, mast cell activation is part of the body's protective response.
Dr. Dempsey explains that in people with MCAS, mast cells may activate inappropriately or release mediators in ways that produce recurring symptoms.
Because mast cells are present throughout the body, abnormal activation can affect multiple organ systems.
MCAS is a recognized clinical condition, but diagnosing it requires more than the presence of nonspecific symptoms. Accepted diagnostic approaches consider characteristic episodes affecting multiple organ systems, objective evidence of mast cell mediator release, and response to appropriate treatment.
Is MCAS an Overactive or Underactive Immune System?
Rich asks whether MCAS should be understood as an overactive immune system, an underactive immune system, or an autoimmune disorder.
Dr. Dempsey explains that she views the problem as potentially involving both excessive activation and impaired regulation.
She describes how mast cells communicate with other immune cells through chemical signals.
In her explanation, persistent mast cell activation may contribute to inflammatory activity while also influencing how other components of the immune system respond.
She suggests that some patients may experience excessive inflammatory signaling alongside less effective immune responses in other areas.
This proposed interaction is particularly important to her approach to patients with complex chronic illness.
However, MCAS is not universally defined as a combination of overactive and suppressed immunity, and the specific mechanisms connecting mast cell activation with persistent tick-borne infections remain under investigation.
Dr. Dempsey's explanation reflects her clinical interpretation of a complicated and evolving area of immunology.
MCAS, Lyme Disease, Bartonella, and Chronic Inflammation
Dr. Dempsey discusses how mast cell activation may intersect with conditions such as Lyme disease, Bartonella infection, and environmental exposures.
She explains that her clinical approach considers both potential triggers and the patient's immune response.
For example, she may evaluate suspected infections or environmental concerns while also addressing symptoms she attributes to mast cell activation.
Her goal is to reduce inflammatory symptoms while investigating other possible contributors to illness.
Dr. Dempsey emphasizes that patients with complex chronic conditions may have multiple overlapping problems that require different approaches.
The relationship between MCAS and persistent symptoms attributed to Lyme disease or Bartonella is an active area of clinical interest, but it has not been established that MCAS is the underlying cause of persistent symptoms in most such patients.
Patients with chronic symptoms benefit from a comprehensive evaluation that considers confirmed infections, other medical conditions, medication effects, and additional potential explanations.
Can Mast Cell Dysfunction Affect Lyme Disease Antibody Testing?
One of the interview's most thought-provoking discussions concerns the interpretation of antibody tests.
Rich asks whether immune dysfunction could affect the reliability of laboratory tests that depend on detecting antibodies.
Dr. Dempsey explains that antibody production depends on immune system activity and raises questions about how abnormal immune responses might affect test interpretation.
She outlines three possible scenarios from her clinical perspective.
Scenario 1: Antibody Production and Potential False Positives
Dr. Dempsey describes patients who produce certain antibodies without having the disease most commonly associated with those antibodies.
For example, she discusses antinuclear antibodies (ANA), which can be found in patients with autoimmune conditions but can also occur in people without a corresponding autoimmune diagnosis.
She questions whether some antibody-based infectious disease results could be influenced by abnormal immune activity.
This is an important distinction: the presence of an antibody does not always establish an active disease.
However, a positive ANA does not by itself demonstrate that Lyme disease antibody tests are unreliable because of MCAS.
Scenario 2: Reduced Antibody Responses and Potential False Negatives
Dr. Dempsey also discusses patients who may have impaired antibody responses.
She suggests that immune dysfunction could contribute to negative antibody results in some patients despite suspected infection.
She references situations in which patients have limited reactivity on Lyme disease immunoblots and do not meet established interpretation criteria.
Antibody tests can indeed be negative early in Lyme disease before an adequate antibody response develops.
However, isolated immunoblot bands are not sufficient to diagnose Lyme disease, and there is not established evidence that MCAS routinely causes false-negative Lyme serology.
Scenario 3: Antibody Tests That Accurately Reflect Exposure
Dr. Dempsey acknowledges that antibody testing can also produce clinically useful results.
She emphasizes the importance of understanding what a particular test measures and how it should be interpreted.
For Lyme disease, validated two-tier serologic testing remains a central diagnostic tool, particularly in patients with later manifestations.
Antibodies may remain detectable long after an infection has been treated, meaning a positive result does not necessarily indicate ongoing active infection.
The central takeaway is that laboratory results must be interpreted within the patient's clinical context rather than viewed in isolation.
For more information, visit Tick Boot Camp's Lyme Disease Testing Resource.
Molecular Testing vs. Antibody Testing for Tick-Borne Infections
Dr. Dempsey explains that she often prefers testing methods intended to identify an organism or its genetic material rather than relying exclusively on antibody measurements.
She discusses molecular testing as an important area of diagnostic development.
Molecular tests, such as polymerase chain reaction (PCR), can detect genetic material from certain pathogens.
These methods can be particularly useful for some infections and clinical situations.
However, their performance depends on factors including the organism, specimen type, timing, disease stage, and laboratory method.
For example, a negative blood PCR test does not reliably exclude Lyme disease, and molecular testing is not universally more accurate than recommended serologic testing.
Dr. Dempsey's discussion highlights her interest in improving diagnostic methods while raising important questions about how immune function may affect test interpretation.
Rich also references conversations with laboratories working on tick-borne disease diagnostics, including IGeneX and Galaxy Diagnostics.
The episode underscores the need for continued development and independent validation of diagnostic technologies.
How Might GLP-1 Medications Affect Mast Cells?
Returning to her research, Dr. Dempsey explains her proposed mechanism for why GLP-1 medications might help some patients with MCAS.
She discusses receptors on the surface of mast cells and the possibility that medications interacting with these pathways may influence mast cell activation.
In her explanation, GLP-1-related signaling could reduce the release of inflammatory mediators.
This could potentially influence symptoms associated with excessive mast cell activity.
She also describes broader immune-modulating effects that may contribute to symptom improvement.
These mechanisms are biologically interesting, but their relevance to human MCAS treatment remains under investigation.
The interview should not be interpreted as establishing that GLP-1 medications directly stabilize mast cells in patients or reliably reverse MCAS-related immune dysfunction.
Ozempic vs. Mounjaro: Is Tirzepatide Better for MCAS?
Rich asks Dr. Dempsey whether she has observed differences between semaglutide and tirzepatide.
Dr. Dempsey explains that both medications have been used in her clinical experience, but she has recently observed encouraging responses with tirzepatide.
She discusses the differences between the two drug classes.
Semaglutide, marketed as Ozempic and Wegovy, acts on GLP-1 receptors.
Tirzepatide, marketed as Mounjaro and Zepbound, acts on both GLP-1 and GIP receptors.
Dr. Dempsey suggests that this dual activity may contribute to differences in inflammatory responses.
She reports that some patients have responded particularly well to tirzepatide.
However, the interview does not present controlled comparative data demonstrating that tirzepatide is more effective than semaglutide for MCAS.
Her observations are preliminary and should not be interpreted as a recommendation to select one medication over another for this unapproved use.
Can GLP-1 Medications Help Patients Who Don't Need to Lose Weight?
One of the most interesting aspects of Dr. Dempsey's discussion involves patients who are not overweight.
She explains that some individuals in her clinical experience have little or no weight to lose.
For these patients, she discusses using very low doses of GLP-1-related medications while carefully monitoring their response.
Dr. Dempsey emphasizes the importance of avoiding unwanted weight loss and muscle loss.
She reports that some patients have experienced improvements in symptoms without substantial changes in body weight.
This raises an important research question:
Could some of the effects of GLP-1 medications on inflammation and immune signaling occur independently of weight loss?
Researchers are investigating the broader physiological effects of these medications, but their use for MCAS in people without an approved indication remains experimental.
GLP-1-related medications can cause significant adverse effects, including gastrointestinal symptoms, dehydration, gallbladder problems, and other complications. They are not appropriate for every patient.
Very-low-dose or microdosing approaches for MCAS have not been established through large clinical trials.
Patients should not begin, modify, or discontinue prescription medications based on this interview.
Why Individualized Treatment Matters
Dr. Dempsey repeatedly emphasizes that patients with MCAS can be unusually sensitive to medications and supplements.
She explains that treatment decisions require careful consideration of each patient's health history, symptoms, tolerability, and medical needs.
She also acknowledges that GLP-1 medications have side effects.
Her research interests focus on identifying treatments that may help patients whose symptoms have been difficult to manage.
However, she does not suggest that every patient with MCAS should receive a GLP-1 medication.
The conversation reinforces the importance of individualized medical assessment, appropriate monitoring, and informed discussions about potential benefits and risks.
Taking MCAS Research to a Larger Audience
Rich congratulates Dr. Dempsey on her growing visibility through major podcast appearances.
They discuss her interview with Dave Asprey and how larger platforms can introduce complex medical topics to audiences who may never have encountered them before.
Dr. Dempsey explains that reaching more people is central to her mission.
Although she continues to care deeply about her own patients, she recognizes that she cannot personally treat everyone seeking help.
Through education, research, professional collaboration, and public conversations, she hopes to improve awareness and encourage other clinicians to learn more about complex chronic illness.
She also expresses appreciation for Tick Boot Camp's role in sharing patient experiences and conversations with healthcare professionals.
The Future of MCAS, GLP-1 Research, and Lyme Disease Care
The interview concludes with excitement about the potential implications of Dr. Dempsey's research.
Her 47-patient case series provides preliminary observations that may help generate hypotheses for future studies.
Important unanswered questions include:
Can GLP-1 medications improve MCAS symptoms in randomized controlled trials?
Which patients, if any, are most likely to benefit?
Do benefits differ between semaglutide and tirzepatide?
Are observed improvements independent of weight loss?
What mechanisms might explain changes in inflammatory symptoms?
What are the long-term risks of using these medications in patients without diabetes or obesity?
Can improved diagnostic methods help distinguish immune dysfunction from active tick-borne infection?
How should clinicians evaluate patients with overlapping symptoms involving MCAS, Lyme disease, and other chronic conditions?
Dr. Dempsey's work highlights why continued scientific investigation is important.
Early findings can generate meaningful questions, but larger studies are necessary before new treatment approaches can become established medical practice.
Key Takeaways From Dr. Tania Dempsey
GLP-1 medications are being investigated for MCAS. Dr. Dempsey discusses research exploring their potential effects on mast cell activity and inflammation.
A 47-patient case series reported an 87% positive response rate. This is a preliminary observation, not proof of effectiveness or a generalizable success rate.
MCAS involves inappropriate mast cell activation. Mast cells release mediators that can contribute to symptoms across multiple organ systems.
Immune regulation is complex. Dr. Dempsey discusses possible interactions between mast cell signaling and other components of the immune system.
Lyme disease testing requires careful interpretation. Antibody tests have strengths and limitations, and results must be considered alongside clinical findings.
Molecular testing offers additional diagnostic tools. Its usefulness depends on the infection, specimen, timing, and validation of the method.
Semaglutide and tirzepatide act through different receptor pathways. Whether one is more effective for MCAS remains unknown.
Weight loss is not the only effect being studied. Researchers are investigating possible metabolic and inflammatory effects beyond weight management.
Safety matters. GLP-1 medications can cause significant side effects, and their use for MCAS remains investigational.
Patients with complex chronic illness need individualized evaluation. Similar symptoms can arise from different conditions and may require different treatments.
Physician education and research collaboration are essential. Dr. Dempsey hopes to expand awareness through ILADS and other professional platforms.
Promising research offers reasons for continued investigation. New findings can inspire hope while still requiring rigorous scientific validation.
Resources Mentioned in This Episode
Related Tick Boot Camp Episodes
Dr. Tania Dempsey: MCAS, Chronic Lyme Disease, GLP-1 Agonists, Biofilms, and Precision Medicine
Tick Boot Camp Doctors Podcast Collection
Tick Boot Camp Podcast – Patient Stories and Expert Interviews
Educational and Professional Resources
International Lyme and Associated Diseases Society (ILADS)
Tick Boot Camp Lyme Disease Testing Resource
Tick Bite Blueprint – Prevention and Post-Bite Guidance
About This LIVE from ILADS Episode
Recorded at the 2025 ILADS Conference in San Antonio, Texas, this episode features returning guest Dr. Tania Dempsey, MD, discussing emerging research into GLP-1 receptor agonists and mast cell activation syndrome.
Together with Tick Boot Camp co-host Rich Johannesen, she explores mast cell biology, inflammation, immune system dysfunction, Lyme disease and Bartonella testing, molecular diagnostics, and her clinical observations involving semaglutide and tirzepatide.
The conversation also highlights her recently published 47-patient case series, her continued involvement with ILADS, and her efforts to educate a wider audience about complex chronic illness.
For people navigating MCAS, Lyme disease, or persistent unexplained symptoms, this episode offers a look at an emerging area of research—and a reminder that scientific progress begins with asking better questions.
Listen to more conversations exploring Lyme disease, tick-borne illness, medical research, and recovery experiences on the Tick Boot Camp Podcast.