San Antonio’s primary functional medicine clinic.

Our clinic is designed to find the root causes of your family’s health concerns and navigate you back to good health. 

Prevention is a cure.

We use natural therapies whenever possible to prevent future illness, to relieve symptoms that reverse the progression of your condition. Our family membership will connect you to our providers and navigate you to the right therapy options.

Office hours

Monday – Friday
10am – 6pm

San Antonio therapies

  • Colon Hydrotherapy
  • Oxygen Therapies
  • HOCATT Sauna
  • Nutrition Support
  • Aesthetic Rejuvenation
  • Max Pulse (blood vessel analysis)
  • Vitamin Infusions
  • Ozone Therapy
  • Hyperbaric Oxygen Therapy
  • Phlebotomy / Blood Draw Services
  • Body Composition
  • ARCC Light Bed Therapy
  • Hyperthermia
  • Cryotherapy

Our providers

Charlotte Widick, APRN, IFMCP

Charlotte Widick, APRN, IFMCP

Nurse Practitioner

About Charlotte

My own health care crisis developed a deep desire to identify the root causes of illness. Each plan is an expression of my goal to create a patient-centered practice with a holistic approach, an empathetic ear, a compassionate heart, and a community vision.

Functional Medicine determines how and why illness occurs and restores health by addressing the root causes of disease for each individual.


Master of Science of Nursing at The University of Texas Health Science Center

Derek Guillory, MD

Derek Guillory, MD

Medical Director

About Derek

I have a passion for functional medicine that was born out of my own personal struggle with health concerns that began before the age of 17. I have an insatiable curiosity for the question most often asked by my patients… “Why am I sick?”

My mission is to be an instrument of personal healing by effectively treating the underlying causes of disease.


Doctor of Medicine (MD) from University of Texas Southwestern Medical Center.

Haley Kraskovic, FNP-C

Haley Kraskovic, FNP-C

Nurse Practitioner

About Haley

Becoming a mom is where I started to develop a passion for natural helathand functional medicine. My goal is to promote holistic health and ensure that patients are truly heard and nurtured through their health journey.

I’m currently pursuing my certification from the Institute of Functional Medicine so as to provide the utmost love and care to our patients.


Master of Science in Nursing from Maryville University.

Start your healing journey. Together.

Frequently asked questions

Should I pay just for what I need?

Our patients who pay-per-service, are generally well and want help with isolated medical questions. They prefer a natural or complementary opinion on treatment options.

The pay-per-service patient will usually need very little contact with a provider and would be willing to wait for an available appointment — knowing that scheduling priority will be given to members.

In addition, sick visits are only allowed to be scheduled AFTER an initial consult has been completed and the provider-patient relationship has been established.

Please keep in mind that every visit would be charged at the regular rate — the initial visit and each subsequent visit.

Is a membership subscription right for me?

Our membership is best for those who desire a long-term partnership with our providers and priority access to our team members, educational resources, and all of our hi-tech and low-tech tools. The membership is an ideal option for those with chronic illness and for those who are generally well.

Members will have priority access to scheduled appointments as well as sick visits. All of the visits are included in the monthly membership fee. The membership has a long list of included benefits, and the list will grow as we continue to add services to care for our loyal clients.

Do you accept insurance?

The short answer is, “No.”

We accept checks, credit cards, and payments from FSA/HSA accounts.

The providers at Root Causes Medical Clinic are not participating providers with any insurance carrier or governmental benefit plan such as medicare or medicaid. We can not accept payments from insurance companies, and we are unable to assist with insurance claims.

Root Causes Medical Clinic will provide each client with a detailed receipt of services performed.

Are the providers at Root Causes primary care physicians?


Root Causes offers primary care in a fee-for-service functional medicine model.

We are primarily consultants and coaches in Functional Medicine, and we will work closely with you to help you address the underlying causes of chronic health problems. Our Providers can confer with your primary care doctor if required.

All patient care is supervised by our medical director. Other practitioners can and will be involved in your care when that care is appropriate, and you will be informed of any such recommendations prior to any changes.

Do you think Root Causes can help me?

Functional medicine providers use a unique approach to uncover the underlying causes of many chronic health care concerns. The human body is intricately complex, and the concerns you are experiencing require careful consideration. The path to healing is best found in a partnership between a patient and a provider working together within a long-term commitment. This process works for the vast majority of patients who commit to the functional medicine approach.