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  • Find the New You

    What will you do after surgical weight loss?

Bariatric Surgery

Weight loss surgery has been identified as an effective, long-lasting treatment for morbid obesity, and its many associated conditions. At the St. John’s Weight Loss Surgery Institute, we understand that surgery is a big decision, which is why our skilled team is here to support and guide you during your journey.

Why Choose Us

Does your weight keep you from living the life that you want? It’s time to Find the New You and we will be your partner on this journey to a healthy life. At the St. John’s Weight Loss Surgery Institute, our bariatric surgeons, Dr.Helmuth T. Billy and Dr. Amir Mehran, along with their medical staff will guide you through all of your weight loss surgery options and help you decide which one is right for you.

National Recognition

We are accredited by the American Society for Metabolic and Bariatric Surgery and have been designated as a BlueDistinction Center by Blue Shield of California.


Distinctions like these recognize our comprehensive and personalized approach to treating our patients and providing tools for lifelong success, including:
  • Pre-surgery Education Seminars
  • Physician Consultations
  • Nutrition Counseling
  • Exercise Planning
  • Support Groups
  • Post-surgery Follow-up

Begin Your Weight Loss Journey Today

Our center is the largest and most established weight loss surgery program in Ventura County and services surrounding areas such as Santa Barbara, Thousand Oaks, Agoura, Moorpark, Simi Valley and into Los Angeles. Our program has been accredited by the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program and is recognized as a Center of Excellence by major insurance carriers.

Sign up today for a no-obligation online or in-person weight loss seminar by calling 844.239.7866. Ask to sign up for the next bariatric seminar.

Take a step to improved health today and register to attend a free educational seminar with a weight loss surgeon. Watch the video below for a preview.


Find The New You

Watch what Danny did after surgical weight loss:

What Will You Do After Surgical Weight Loss

If you’ve felt trapped by your body, it might be time to make a change. Our team of experts at the St. John’s Weight Loss Surgery Institute will support you through every step of the process. Our comprehensive bariatric program is designated a center of excellence and rated Top Ten Percent in the Nation.

Weight Loss Surgery Procedures

All of our weight loss surgeries are performed using minimally invasive techniques, which generally result in smaller incisions, shorter hospital stays, fewer complications, and faster recovery times.

Roux-en-Y Gastric Bypass

  • During a Roux-en-Y gastric bypass procedure, your surgeon bypasses a portion of your intestine and reduces your stomach to a small pouch, roughly the size of an egg. 
  • This gastric bypass procedure reduces the amount of food you can consume, resulting in weight loss. 



Sleeve Gastrectomy

  • During a Sleeve Gastrectomy, your surgeon creates a small, sleeve-shaped stomach (about the size of a banana) by removing most of your stomach.
  • This procedure is restrictive in that it reduces the amount of food that your stomach can hold.
  • This procedure is not reversible.

Gastric Banding

  • During Gastric Banding, a silicone band is placed around the upper portion of your stomach to decrease the amount of food your stomach can physically hold.
  • The band is connected by plastic tubing to an access port under the skin. Adjustments can be made to customize band size by injecting saline making the band tighter or looser to fit your needs.
  • There is no cutting or stapling of the stomach and the procedure is completely reversible if necessary.


In addition to these primary procedures, St. John’s offers multiple revision procedures for patients who have previously undergone bariatric surgery.

Weight Loss Surgery Procedures

Am I A Candidate For Weight Loss Surgery

You may be a candidate for bariatric surgery if you’re severely obese, other weight loss treatments haven’t worked for you, and your Body Mass Index (BMI) is greater than 35 with other health problems or your BMI is greater than 40 without co-morbidities.

Calculate Your BMI

Body Mass Index (BMI) is a measure of the degree of your excess weight, based on weight and height. BMI is calculated by dividing body weight in pounds by height in inches squared and multiplying that amount by 704.5. This provides a metric calculation for BMI.

Calculate Your BMI

Is Weight Loss Surgery Covered By My Insurance

Many health insurances cover weight loss surgery but each plan is different and may have different guidelines. To see if you are covered and qualify for surgery, please call our insurance coordinator at 805.981.7305 with your plan information. 

Take Our Free WeightAware Assessment

Take our free WeightAware risk assessment

Register for an Upcoming Weight Loss Seminar

St. John’s Weight Loss Surgery Institute offers free weight loss seminars, where you can find out what weight loss options might be right for you. Call to register at 877.753.6248. 

Surgical Weight Loss Informational Seminars