Message the practice through WildRoot

PH

Peak Health Institute - Functional Medicine

Medical Center in Warrenville, ILOpens 9:00 AM

4.9 · 117 Reviews

Consultation & booking

What this place offers

Hospital
Consultant
Doctor
Credit card payment
Contactless payment
Wheelchair accessible

Meet the team

K

Katie Mcmanigal

Founder & Medical Director

Katie McManigal is a board-certified family nurse practitioner who specializes in functional and regenerative medicine. She began her career as a Neonatal Intensive Care Unit RN at Lurie Children’s hospital. During this time, she developed and honed the critical thinking skills necessary to uncover and support complex health issues and conditions.

Functional medicineRegenerative medicineComplex health issuesHuman function optimizationPersonalized care plansGut health planHormone replacement therapyLifestyle support
Education: Purdue University, The Institute for Functional Medicine, The American Academy of Anti-Aging Medicine (A4M), SopMED, The International Lyme and Associated Diseases Society (ILADS)
J

Jessica Montalvo

Functional Medicine, Medical Doctor

Jessica received her bachelor’s degree in English and American literature from Harvard University. She attended the University of Rochester School of Medicine. She completed a residency in internal medicine at Northwestern in Chicago and subsequent training in hospice and palliative medicine.

Functional medicineInternal medicineHospice and palliative medicineReversing cognitive declineComplex chronic illnessTickborne infections
Education: Harvard University, University of Rochester School of Medicine, Northwestern, Institute for Functional Medicine, ADAPT Functional Medicine Practitioner Training and Certification Program, Dr. Dale Bredesen’s training in Reversing Cognitive Decline (RECODE program), Dr. Tom Moorcroft’s Lyme Disease Practitioner Certification
K

Kelsie Lazzell

Naturopathic Doctor

Dr. Kelsie Lazzell is a dual‑trained naturopathic doctor and doctor of chiropractor at Peak Health Institute, dedicated to empowering your body’s innate healing capacity. Grounded in the naturopathic principle of working with the body rather than against it, she blends foundational lifestyle interventions—targeted nutrition, movement, stress management, and gentle detoxification—with advanced therapies like botanical and nutraceutical support, IV nutrient infusions, and peptide protocols.

Naturopathic medicineChiropracticLifestyle interventionsTargeted nutritionMovementStress managementGentle detoxificationBotanical supportNutraceutical supportIV nutrient infusionsPeptide protocolsMold/mycotoxin exposureChronic viral infectionsAutoimmune disordersChronic fatigueCortisol dynamicsThyroid dynamicsSex‑hormone dynamicsAcupuncture
J

Jordan Neumann

Board-Certified Family Nurse Practitioner

Jordan Neumann is a Board-Certified Family Nurse Practitioner who brings a wealth of experience and a passion for functional medicine to Peak Health Institute. She graduated with her Doctorate of Nursing Practice from Rush University, where she also completed rigorous training in various medical disciplines.

Functional medicineEmergency medicineOutpatient allergy & immunologyChronic illnessLyme diseaseMold toxicityAutoimmune diseaseHealth optimizationInfusion therapiesPreventative medicineThyroid healthWomen’s healthHormone optimizationFertilityChronic/reactivated infection managementMold/CIRS therapyLyme disease and coinfection therapyGastrointestinal optimization
Education: Rush University
R

Racheal Feliz

Nurse Practitioner | Functional & Regenerative Medicine

Racheal Feliz is a Board-Certified Nurse Practitioner with 19 years of experience in the medical field. She received her Bachelor of Science in Nursing from Indiana Wesleyan University and her Master of Science as a Family Nurse Practitioner from Chamberlain University.

Regenerative medicineAlternative therapy for musculoskeletal conditionsJoint degenerationChronic inflammatory diseaseAdvanced lab interpretationHormonal optimizationMetabolic restorationSexual wellnessPeptidesFunctional care
19+ yearsEducation: Indiana Wesleyan University, Chamberlain University

Services

NAD+ Therapy

Peptide Therapy

Hormone Replacement Therapy

Ozone Therapy

Functional Medicine

Regenerative Medicine

Lab Testing

Nutritional Counseling

Acupuncture

Modalities

Functional Medicine

Natural Healing

Regenerative Medicine

IV Therapy

Peptide Therapy

Chiropractic Adjustment

Acupuncture

Frequency Specific Microcurrent

Hormone Therapy

Lifestyle Medicine

Platelet-Rich Plasma Therapy

Ozone Therapy

Joint Injections

Conditions treated

Chronic ConditionsStressDigestive IssuesHormonal ImbalanceMusculoskeletal ConditionsJoint PainDetoxificationAutoimmune ConditionsFatigueHypothyroidismLyme DiseaseCognitive Decline

What to expect on your first visit

During your first appointment, your care provider will take a comprehensive health history to understand the complete picture of your health. We will then run comprehensive lab tests to determine the health of a variety of systems. With the information gathered, your care provider will develop a unique therapy plan to optimize your health, heal any systems in distress, and make recommendations to improve your overall quality of life.

From our patients

“Highly recommend to anyone looking for top-notch health services!”

“Katie and team are incredible. Whenever I have issues, I go to her first. I can’t recommend her and the team enough!”

“I highly recommend it to anyone striving to become a better version of themselves, it’s a true destination for all things health and wellness.”

“The front desk staff are consistently helpful, and the providers truly care about addressing my health concerns. I always feel genuinely heard, a rarity in my healthcare experience.”

“Dr.Montalvo and her staff are amazing! Her nurse Vanessa is so compassionate in providing patient care. They really address your health needs I absolutely recommend Peak Health Institute for all your health and wellness needs.”

About this place

Achieve peak health with functional medicine in Chicagoland. Our doctors take an integrative and functional approach to optimizing your health.

Practice Philosophy

Healthcare shouldn’t be reserved for when you’re ill. Integrative medicine offers a preventative model of care that will give you the tools and empowerment to reach peak performance and stay there.

Where you'll be

3S517 Winfield Rd B, Warrenville, IL 60555, USA
Get Directions

Business hours

Monday: 9:00 AM – 5:00 PM
Tuesday: 9:00 AM – 5:00 PM
Wednesday: 9:00 AM – 5:00 PM
Thursday: 9:00 AM – 5:00 PM
Friday: 9:00 AM – 5:00 PM
Saturday: Closed
Sunday: Closed

4.9 · 117 Reviews

L

Lemurian Donna Carol

3 months ago

I am happy that I have found Peak Health Institute. Their work is comprehensive and clear. After blood and stool testing, I know exactly what I am deficient in, especially regarding hormones. I am now receiving treatment and have full trust in my healthcare professional there, as she is an expert in functional medicine. It is not cheap but if you want real results healing your fatigue, etc., this is the place!

I

Inga Tice

9 months ago

I’ve been on a long and challenging journey dealing with Lyme disease, mold toxicity, and heavy metal detox. After visiting numerous offices and trying countless protocols over the years, nothing truly clicked—until I found Peak Institute. The team at Peak is truly exceptional. Their attention to detail is unmatched, and what sets them apart is their ability to look at the full picture rather than just isolated symptoms. They approach healing with a wide-ranging perspective, integrating multiple disciplines and innovative treatments in a way that feels both grounded and deeply personalized. Every appointment is punctual, and the environment is warm, professional, and genuinely caring. From the moment you walk in, you feel seen, heard, and supported—not just as a patient, but as a whole person. They work with compounding pharmacies and my prescription is sent immediately. All their staff members are very caring and I have seen them for a long time. I’m also very glad that I can draw the blood at their clinic. So convenient! Thanks to Peak Institute, I’m finally experiencing real, sustainable progress in my healing journey. I’m incredibly grateful for their expertise, compassion, and the hope they’ve restored in my life. If you’re looking for a team that truly understands complex, chronic conditions and how to treat them at the root—this is the place.

N

Nina Norasith

a year ago

We are so thankful to Peak Health for all the amazing experiences we've had with our girls! Without the care and support of their practice, we wouldn't have been able to get the IV therapy our girls needed. The team is always professional, friendly, and truly dedicated to helping their patients. Highly recommend to anyone looking for top-notch health services!🩷

C

Concept Roses

a year ago

Dr.Montalvo and her staff are amazing! Her nurse Vanessa is so compassionate in providing patient care. They really address your health needs I absolutely recommend Peak Health Institute for all your health and wellness needs.

L

Lisa Keller

10 months ago

I have been to Peak Health a total of 5 visits beginning in April of 2024 for HRT and saw 3 different providers, all due to staff departures. I just learned that the last one has recently left, which would put me at #4 if I continued. Clearly, they have high practitioner turnover. In additional to this, I offer the following as a few main reasons that I do not recommend them: They have no relationships with any local compounding pharmacies. This matters if you do not want your prescriptions shipped. I was referred by one practitioner to a local compounding pharmacy that did not even provide the service pertaining to the script. This is something they clearly should know. They are a hard sell on pellets, even though I told them repeatedly I was a hard “no” and absolutely NOT interested in them. Still, this came up in EVERY visit and MY reasoning was challenged quite forcefully. I received mixed messages about available therapies from the same practitioner on multiple occasions. Usually accompanied by a strong redirect to their ‘preferred’ formulas (compounded vs. FDA approved). Labs drawn at their facility (contracted with HealthLab) take 2-3 weeks for results to come back. For self-pay on labs, they will not provide up front pricing. For a recent hormone only panel, the total charges were $2,296.00, of which the self-pay portion owed was $803.60. This was substantially different from the prior time I had this same panel and paid only $110.80 out of $2,216.00. Obviously, these prices are grossly inflated. In attempt at resolving this discrepancy, I was told that Peak Health has absolutely nothing to do with the lab services billing and that there are no negotiated rates or discounts with the lab, and they deny making any profit from the tests they order. There are better alternatives that will provide up front pricing and have much faster turnaround. Peak Health will however work on steering you - two of the practitioners mentioned that other labs could render inaccurate/skewed results; leading you to believe others are not to be trusted and using “their lab service” is the only way to go. My impression of Peak Health is they appear to be more concerned about upselling you and using their ‘preferred’ products/services, in order to maximize profits than they are about actual patient results, at least mine. They have fumbled my care repeatedly, including prescriptions getting called in/refilled, inaccurate clinical history, lack of preparation for appointments, poor bedside manner, conflicting messages, and overall lack of accountability when challenged on issues. There is far better care available elsewhere.