WELCOME to
Root Causes Medicine
Root Causes Medicine
Where Hope Takes Root & Health Comes to Fruition
Where Hope Takes Root
& Health Comes to Fruition
Can I book directly with Dr. Guillory?
We care for patients from all over the country. To ensure everyone receives quality care, Dr. Guillory works with a team of highly skilled nurse practitioners and a naturopathic oncologist who handle all patient intakes. Dr. Guillory does not do initial intakes. Once your intake is complete and you’ve started your membership, you may request a consultation with Dr. Guillory, subject to approval.
What is the cost of an intake with a nurse practitioner?
The intake visit with a nurse practitioner is $600. In rare cases—typically for complex, chronic illness patients—an additional intake may occur with Dr. Guillory. Your NP will let you know during your visit if this applies to you.
What’s included in the membership?
Membership includes:
- Up to one 25-minute follow-up visit per month with your nurse practitioner (as needed)
- 20% off IV therapies
- 20% off supplements from Fullscript
- Access to our patient portal for brief questions and appointment booking
- Ability to schedule additional therapies and visits (at discounted rates)
- Have a cough, rash, fever? Pay only for the treatment you receive and see an acute care provider at no additional charge.
Is membership required?
Yes, we are a membership-only clinic.
How much is the monthly membership?
$300 per month.
When do I need to begin membership?
Membership begins right after your intake appointment—unless you are enrolled in our intensive program, in which case membership begins after the intensive is complete.
Is bloodwork included in the intake or membership?
No, bloodwork is billed separately. Some lab work may be covered by your insurance. We offer on-site blood draws through Quest Diagnostics at discounted rates to help reduce your out-of-pocket costs if insurance doesn’t cover everything.
What does a full cancer patient intake include?
The cancer intake begins with a $600 screening visit with Dr. Lucas. This appointment is conducted via Zoom and allows him to assess your diagnoses, prognosis and determine your fitness for treatment at Root Causes. If approved for treatment, your next step is to schedule a full initial intake, an in-person visit with Dr. Lucas and a subsequent appointment with Dr. Guillory, our medical director, for an additional $600. From there, your care plan could include our Direct Access Program, Standard Access Membership or remote (at home) treatment.
What is the cost of the Direct Access Program and what's included?
Luke has a detailed sheet outlining the intensive program’s pricing and services. Please refer to that for the full breakdown.
Can I book colon hydrotherapy (CHT) without becoming a member?
In Texas, a prescription is required for colon hydrotherapy. If you don’t already have a provider, we offer a mini intake with one of our nurse practitioners for $75. New CHT patients must book two sessions in a row:
- Mini intake + 2 CHT sessions:
$425 total - Future sessions without membership:
$175 each
Do you offer payment plans or financing options?
Not at this time. We are actively exploring financing partners but have yet to find a solution that’s a win-win for both patients and the clinic.
Membership Program
Welcome to Root Causes Medicine — we’re so glad you’re here. You’ve taken a powerful first step toward long-term, root-level healing. We are deeply committed to helping you uncover the true causes of your symptoms and build a personalized path to wellness. Whether you’re managing a chronic illness or simply seeking to optimize your health, our integrative team is here to partner with you every step of the way. With priority access to expert care, advanced therapies, and whole-person support, your journey to healing starts now — and we’re honored to walk it with you.
Your Membership Includes:
In-Person & Virtual Visits
Appointments can be held in-person, by phone or Zoom. All patients who do not reside in Texas must have one in-person visit a year.
Personalized Health Plan
Your provider will create a treatment plan based on you and your goals.
Access to Testing
Access to lab testing, genetic testing, nutritional supplementation, peptides, and certain medications, at reduced costs.
Nutritionist Support
Health starts in the gut. Work with your nutritionists to create a meal plan that fits your lifestyle.
Priority Scheduling
You receive same-day appointments, as often as possible.
Access to Therapies
-
- Ozone
- Bemer
- Hugo
- Cryotherapy
Your Health Team
Derek Guillory, MD
Medical Director
About Dr. Guillory
Derek W. Guillory, MD, our founder and Medical Director, has a passion for functional medicine that was born out of his own personal struggle with health concerns that began before the age of 17. He has an insatiable curiosity for the question most often asked by his patients… “Why am I sick?”
Dr. Guillory became one of the first certified functional medicine practitioners in Texas in 2015. He earned his Bachelor of Science in Education at Baylor University in 1997, graduating Magna Cum Laude. In 2001, he graduated from the University of Texas Southwestern Medical Center in Dallas. He continued his medical training in Emergency Medicine at UT Southwestern Medical Center, graduating in 2004. He has been continuously Board Certified by the American Board of Emergency Medicine since 2005.
Lucas Tims, ND, FABNO
Naturopathic Oncologist
About Dr. Lucas
Originally from Northwest Arkansas, Dr. Lucas Tims is a graduate of the University of Arkansas, where he majored in microbiology. He went on to complete his medical training at Southwest College of Naturopathic Medicine in Tempe, Arizona before moving to Tulsa, Oklahoma for an oncology-focused residency program at City of Hope (formerly known as Cancer Treatment Centers of America). In 2013, he passed additional board exams to become a Fellow of the American Board of Naturopathic Oncology (FABNO).
Luke Schulte-Ovalle, Psy D, NRP
Psychologist
About Luke
Since 1998, Luke’s career in emergency, prehospital medicine has taken him across the country–from search and rescue and community preparedness with local and regional fire departments to national disaster response with federal agencies and the American Red Cross to the international level with the Defense Institute for Medical Operations and the International Trauma Life Support Program.
His work with EMS and domestic flight crews in the Baltimore/DC Metro area pre- and post-9/11 reinforced his belief in the need for proactive mental healthcare for first responders.
He began studying clinical psychology and human behavior at American Military University and completed his studies at the University of Maryland. Now as a functional psychologist, Luke brings a unique, compassionate insight to his approach to medicine and mental health. His contributions to the care plans of all Root Causes members include a variety of emotional and spiritual support strategies.
Charlotte Widick, APRN, IFMCP
Nurse Practitioner
About Charlotte
Charlotte’s own health care crisis developed a deep desire to identify the root causes of illness. Each plan is an expression of her goal to create a patient-centered practice with a holistic approach, an empathetic ear, a compassionate heart, and a community vision.
Charlotte has been in health care for almost 40 years. She has a Master of Science of Nursing with certifications in Emergency and Acute Care and has been a nurse practitioner since 1998.
Haley Kraskovic, FNP-C
Nurse Practicioner
About Haley
I have been blessed to be in nursing for 20 years. I began my career in intensive care, working in a variety of specialties ranging from burn/trauma to pediatrics. I then transitioned into transplant and organ donation and had the privilege of standing by donor families as they made incredibly tough decisions. As I progressed in my career and had my two beautiful children, I began to embrace a more natural and holistic approach to my and my families health.
As I entered Nurse Practitioner Graduate school, my only goal was to practice functional medicine. I was blessed to meet Dr. Guillory and began my career in functional medicine with Root Causes Medicine.
I have spent the last 4 years caring for my patients of all ages helping them heal from their chronic illnesses. I am very passionate in ensuring that my patients and I are working together in a collaborative approach to their health.
I fully believe that my patient’s health journeys should be a positive, empowering experience, rooted in a strong, meaningful partnership with your practitioner and care team.
Christal Carter, APRN
Nurse Practitioner
About Christal
Driven by her own journey to improve her health, and witnessing the challenges of the established healthcare system, Christal Carter, FNP, followed her passion to specialize in Integrative Medicine. She has 15 years of nursing experience that has spanned the country, including a fellowship at the Andrew Weil Center for Integrative Medicine at The University of Arizona. More recently, after a first-hand struggle with toxic mold, she has developed a passion for environmental medicine. Christal strives to meet patients where they are at on their health journey, serving as a compassionate guiding light while allowing patients to find empowerment from within to live their fullest expression of health.
Membership Program
Welcome to Root Causes Medicine — we’re so glad you’re here. You’ve taken a powerful first step toward long-term, root-level healing. We are deeply committed to helping you uncover the true causes of your symptoms and build a personalized path to wellness. Whether you’re managing a chronic illness or simply seeking to optimize your health, our integrative team is here to partner with you every step of the way. With priority access to expert care, advanced therapies, and whole-person support, your journey to healing starts now — and we’re honored to walk it with you.
Your Membership Includes:
In-Person & Virtual Visits
Appointments can be held in-person, by phone or Zoom. All patients who do not reside in Texas must have one in-person visit a year.
Personalized Health Plan
Your provider will create a treatment plan based on you and your goals.
Access to Testing
Access to lab testing, genetic testing, nutritional supplementation, peptides, and certain medications, at reduced costs.
Nutritionist Support
Health starts in the gut. Work with your nutritionists to create a meal plan that fits your lifestyle.
Priority Scheduling
You receive same-day appointments, as often as possible.
Access to Therapies
-
- Ozone
- Bemer
- Hugo
- Cryotherapy
Your Health Team
Derek Guillory, MD
Medical Director
About
Derek W. Guillory, MD, our founder and Medical Director, has a passion for functional medicine that was born out of his own personal struggle with health concerns that began before the age of 17. He has an insatiable curiosity for the question most often asked by his patients… “Why am I sick?”
Dr. Guillory became one of the first certified functional medicine practitioners in Texas in 2015. He earned his Bachelor of Science in Education at Baylor University in 1997, graduating Magna Cum Laude. In 2001, he graduated from the University of Texas Southwestern Medical Center in Dallas. He continued his medical training in Emergency Medicine at UT Southwestern Medical Center, graduating in 2004. He has been continuously Board Certified by the American Board of Emergency Medicine since 2005.
LUCAS TIMS, ND, FABNO
Naturopathic Oncologist
About
Originally from Northwest Arkansas, Dr. Lucas Tims is a graduate of the University of Arkansas, where he majored in microbiology. He went on to complete his medical training at Southwest College of Naturopathic Medicine in Tempe, Arizona before moving to Tulsa, Oklahoma for an oncology-focused residency program at City of Hope (formerly known as Cancer Treatment Centers of America). In 2013, he passed additional board exams to become a Fellow of the American Board of Naturopathic Oncology (FABNO).
Luke Schulte-Ovalle, Psy D, NRP
Psychologist
About
Charlotte Widick
APRN, IFMCP
Nurse Practitioner
About
Charlotte’s own health care crisis developed a deep desire to identify the root causes of illness. Each plan is an expression of her goal to create a patient-centered practice with a holistic approach, an empathetic ear, a compassionate heart, and a community vision.
Charlotte has been in health care for almost 40 years. She has a Master of Science of Nursing with certifications in Emergency and Acute Care and has been a nurse practitioner since 1998.
Haley Kraskovic, FNP-C
Nurse Practicioner
About
I have been blessed to be in nursing for 20 years. I began my career in intensive care, working in a variety of specialties ranging from burn/trauma to pediatrics. I then transitioned into transplant and organ donation and had the privilege of standing by donor families as they made incredibly tough decisions. As I progressed in my career and had my two beautiful children, I began to embrace a more natural and holistic approach to my and my families health.
As I entered Nurse Practitioner Graduate school, my only goal was to practice functional medicine. I was blessed to meet Dr. Guillory and began my career in functional medicine with Root Causes Medicine.
I have spent the last 4 years caring for my patients of all ages helping them heal from their chronic illnesses. I am very passionate in ensuring that my patients and I are working together in a collaborative approach to their health.
I fully believe that my patient’s health journeys should be a positive, empowering experience, rooted in a strong, meaningful partnership with your practitioner and care team.
Christal Carter, APRN
Nurse Practitioner
About
Driven by her own journey to improve her health, and witnessing the challenges of the established healthcare system, Christal Carter, FNP, followed her passion to specialize in Integrative Medicine. She has 15 years of nursing experience that has spanned the country, including a fellowship at the Andrew Weil Center for Integrative Medicine at The University of Arizona. More recently, after a first-hand struggle with toxic mold, she has developed a passion for environmental medicine. Christal strives to meet patients where they are at on their health journey, serving as a compassionate guiding light while allowing patients to find empowerment from within to live their fullest expression of health.
Pricing
Appointment Fees
- Speak with Patient Care Coordinator = No Charge
- Screening Visit with Dr. Lucas = $600
- In-Person Visit with Dr. Guillory = $600
- Direct Access Program = Pricing & Details
- Monthly Membership = $300/mo
(+$100 per additional qualifying family member)
Cancer recovery patients can learn more about our Integrative Oncology Program here.
All patients can access our 2026 Membership Agreement here.
Before your first appointment…
Please take a few moments to complete the forms below. Each one is designed to help us understand your unique needs, preferences, and health history so we can offer the most personalized care possible.
HIPAA
All forms are fully HIPAA compliant and securely submitted through our system.
1
Patient
Information
This form offers Root Causes a snapshot of your symptom patterns over the past 14 days, helping guide personalized care and identify areas for support.
Estimated Time:
8 – 12 mins
2
Enrollment
Consent
A supportive overview, that helps you understand the heart of functional medicine, your relationship with our team, and the program details.
Estimated Time:
4 – 5 mins
3
Medical Symptoms
Questionaire
This form offers Root Causes a snapshot of your symptom patterns over the past 14 days, helping guide personalized care and identify areas for support.
Estimated Time:
5 – 7 mins
Form 4 is for cancer patients initial screening visit with Dr. Lucas only.
4
Cancer patient
screening
This form gives Root Causes a personalized view of your health journey to date, helping us tailor your care.
Estimated Time:
8 – 12 mins
The natural healing force within each of us is the greatest force in getting well.
— Hippocrates
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