Our Team

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.

Having experienced her own myriad of unexplained health symptoms throughout her life, through rigorous training and education, Katie discovered ways to heal and optimize the human function. As a result of this journey, it became Katie’s mission and passion to help those chronically sick regain their health, wellness, and happiness.

Katie’s extensive field training and education has uniquely prepared her to understand the complexities of each individual. Her approach to functional medicine focuses on creating a personalized care plan specific to an individual’s biological needs, and tailored to meet each individual’s health goals. Katie completed her nurse practitioner degree at Purdue University. She has continued her education and training in functional medicine with The Institute for Functional Medicine, The American Academy of Anti-Aging Medicine (A4M), SopMED, and The International Lyme and Associated Diseases Society (ILADS).

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.

After 10+ years of practice in the hospital and home based settings, she felt ready for a new challenge. Jessica decided to study functional medicine so she could impact the health and well-being of her patients by working on root causes of their symptoms. She pursued training with the Institute for Functional Medicine and the ADAPT Functional Medicine Practitioner Training and Certification Program., earning the status as Certified Practitioner for both in late 2019. Jessica also completed Dr. Dale Bredesen’s training in Reversing Cognitive Decline, known as the RECODE program. She also has training in Frequency Specific Microcurrent therapy

She was chosen to work for Chris Kresser’s telehealth practice Adapt180, and she continued caring for her patients through the California Center for Functional Medicine. Her work with both entities introduced her to the management of patients with tickborne infections. Jessica realized that she enjoyed this population, and that she needed more training to better care for her patients. She took part in Dr. Tom Moorcroft’s Lyme Disease Practitioner Certification, a small group mentorship combining didactic learning with case discussion and focusing on the therapy of tickborne infection and related conditions. She remains part of the Lyme Inner Circle.

Jessica has an interest in supporting a wide variety of conditions. She blends her knowledge of conventional medicine with functional and integrative medicine therapies and principles. Jessica has strong interests in reversing cognitive decline and supporting complex chronic illness.

Jessica spent her formative years on the East Coast and will always be a Jersey girl at heart. In her spare time, she and her husband indulge in adventures with their 2 Rottweilers.

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. Dr. Lazelle’s holistic framework ensures that each care plan is as unique as the individual, fostering sustainable wellness from the inside out.

Leveraging cutting‑edge functional laboratory testing, Dr. Lazzell paints a comprehensive picture of your physiology—uncovering hidden imbalances across hormone panels, digestive markers, toxin burdens, and chronic infections. She brings particular expertise in complex, multi‑system conditions including mold/mycotoxin exposure, chronic viral infections (such as Epstein–Barr), autoimmune disorders, and chronic fatigue. Her in‑depth understanding of cortisol, thyroid, and sex‑hormone dynamics, combined with her additional training in chiropractic adjustment and acupuncture, allows Dr. Lazelle to deliver a truly integrative, whole‑body approach. She is committed to guiding you toward optimal health, resilience, and vitality at every stage of your journey.

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.

With over five years of experience in emergency medicine, outpatient allergy & immunology, and as a frontline COVID-19 nurse, Jordan has witnessed firsthand the importance of addressing the root causes of health issues rather than just supporting symptoms. Her experiences during the pandemic, in particular, underscored the need for a more comprehensive approach to patient care, prompting her to seek opportunities in functional medicine while completing her doctorate.

For the past two years, Jordan has immersed herself in the field of functional medicine, diving deep into the complexities of chronic illness, Lyme disease, mold toxicity, autoimmune disease, and health optimization. Her commitment to understanding and supporting these intricate conditions has enabled her to provide patients with effective, root-cause solutions that promote long-term wellness.

Jordan is highly skilled in infusion therapies for health optimization and the therapy of both acute and chronic conditions. Her dedication to functional medicine is driven by a desire to offer patients holistic solutions to complex health issues, aiming for long-term wellness rather than temporary fixes.

Her areas of focus include:

• Preventative medicine
• Thyroid health
• Women’s health (including hormone optimization and fertility)
• Allergy & immunology
• Chronic/reactivated infection management
• Mold/CIRS therapy
• Lyme disease and coinfection therapy
• Gastrointestinal optimization

Jordan is committed to working alongside her patients, providing integrative and personalized therapy plans to address both acute and chronic concerns. At Peak Health Institute, Jordan looks forward to partnering with her patients on their health journeys, helping them achieve optimal well-being through a holistic and integrative approach.

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.

Racheal specializes in regenerative and alternative therapy options for musculoskeletal conditions, joint degeneration, and chronic inflammatory disease. Her approach focuses on healing damaged tissue, restoring mobility, and helping patients avoid unnecessary surgery. Over the years, she has helped countless individuals throughout the Chicagoland area return to active, pain-free living.

In addition to regenerative medicine, Racheal has dedicated extensive training to advanced lab interpretation, hormonal optimization, and metabolic restoration. She builds individualized therapy plans designed to support long-term energy, balance, and vitality — often hearing the same meaningful feedback from patients:

“I haven’t felt this good in years.”

Racheal also specializes in sexual wellness for both men and women, recognizing the essential role intimacy plays in emotional well-being, relationship connection, and quality of life. Through the use of peptides and regenerative therapies, she helps patients restore libido, sexual confidence, and healthy function — supporting deeper connection and stronger relationships.

Her years of experience in functional and regenerative care have cultivated a deep passion for helping people feel like themselves again — inside and out. She approaches each patient with compassion, curiosity, and a commitment to excellence, prioritizing individual goals, education, and lasting results. Racheal is dedicated to helping her patients look, feel, and live their best — and she believes that when the body is supported correctly,
healing and vitality are absolutely possible.