We are training other doctors in the technique and building a provider network. Like any new technique, the medical community takes some time to adopt the procedure. To see if there is a doctor in your area, click here.

Based on the research in this area, local cell type, pressure, and chemical environment also help the cells to determine which type of cells will be formed.

Unlike embryonic stem cells, adult stem cells do not generally keep growing, even in culture. For example, most patients whose stem cells we grow to bigger numbers in the lab will lose their ability for continued cell growth after just a few weeks. In addition, the same body signals that would tell these cells to stop growing in healing a normal fracture or ligament tear are still present in your body.

The basic science on adult stem cells shows that if the cells are kept in culture for short periods, that there is no risk of the cells becoming cancerous. We have published the world’s largest (to date) safety and complications tracking study of adult stem cell use in patients. This study did not show any serious stem cell related complications and it did not show that any patient developed a stem cell related cancer. Finally, we maintain an extensive complications tracking database with patient contacts at specified times. We have seen no evidence of significant complications at these re-implant sites. We also work with an outside lab for quality to clear each patient’s cells before they are used in treatment as an additional safety check.

Mesenchymal stem cells will stop proliferating when they physically contact each other (otherwise known in cell culture lingo as “confluence”). Culturing these cells, it becomes obvious that once they reach that point, they refuse to continue to grow (proliferate). This is because they are repair cells and when an area in need of repair is fully covered, they get the signal to stop growing. In the approximately 60 patients where we have ongoing MRI surveillance of the re-implant sites, there has been no evidence of overgrowth where the regeneration has surpassed “expected optimal growth”.

MSC’s do stay local at the injection site across multiple studies. This is likely linked to the fact that they generally do not circulate in the blood stream like other adult stem cell types and are primarily found resident in the tissues they serve.

AZ Pain Centers developed a new advanced medical technique called Comfort Technology™ which allows even the most pain sensitive patients to get the help they need. The medications and the techniques used were designed to eliminate pain, not cause more. Most patients will tell us that the procedures are painless, but everyone’s pain tolerance is different. Some describe the procedure as simple pressure, some as being snapped by a rubber band or a slight sting and others claim no pain at all. It is our goal to make the treatment a positive, safe and effective experience to have you back in action as quickly as possible.

Your Doctor can best answer this question at your consultation. It will depend on the condition that is being treated.

In most cases 15 to 30 minutes.

The treatment has proven to be safe and easy, we encourage you to stop pain medications, including over the counter pain medications, Eight (8) hours in advance. Stop blood thinners 48 hours in advance. Please discuss this with the prescribing Doctor prior to discontinuing blood thinners to be sure it is safe for you to do so. You will want to have a light snack before the treatment. Eating before the procedure can reduce a drop in blood sugar to which some people may experience due to fear.

Regenexx FAQs

The Regenexx procedures performed in the United States are compliant with CFR 21 Part 1271 and fall under the same surgery exemption discussed in 1271.15 (b).

All of the Regenexx Stem Cell and Blood Platelet Procedures performed in the U.S. today are same-day procedures that are compliant with CFR 21 Part 1271, falling under the same surgery exemption discussed in 1271.15 (b). Unfortunately, there still remains some confusion about Regenexx, largely as a result of a few individuals who have written about our case against the FDA throughout the last few years, but who did not fully understand that the case relates only to the Regenexx-C Procedure. This single procedure, which is different from the procedures now performed in the USA, is only available in the Cayman Islands through an independent vendor who has licensed the procedure and has not been performed in the U.S. since August of 2010. fda_page_graphic Regenexx FAQ

What’s the Difference Between these Procedures?

regenexx_compare Regenexx FAQAll of the procedures performed in Colorado and throughout our U.S. Regenexx Procedure Network are same-day procedures. This means that the patient’s cells are harvested in the morning, isolated and processed, then re-injected into the patient’s injured area – all within a period of a few hours. The Regenexx-C Procedure, which is only performed at Regenexx Cayman, involves harvesting the cells on the patient’s first visit, growing them to larger numbers over approximately two weeks, testing the cells, then re-injecting the cells during the patient’s second visit. Dr Chris Centeno explains the FDA’s stance on the Regenexx-C cultured stem cell procedure, which has not been performed in the United States since 2010 (currently offered by Regenexx Caymen): [Disclaimer: The Regenexx™ same-day procedures are performed in the United States. The Regenexx-C cultured stem cell procedure is only offered outside the U.S. through independently owned and operated medical services providers operating exclusively in countries that allow autologous cultured cells to be used through their local regulatory structure. These service providers are not part of nor affiliated with the Centeno-Schultz Clinic nor any U.S. Regenexx Network provider. The Regenexx-C procedure licensed by these entities is not approved by the U.S. FDA for use in the United States.]
hqdefault Regenexx FAQ

No. PRP is concentrating platelets in the blood, not stem cell therapy. This is a more detailed discussion on the differences between PRP and stem cell therapy. In addition, while PRP is one component of the therapy, we use a very different “Super Platelet Mix’ which we believe helps to produce many more stem cells.

We do offer the Regenexx-SCP procedure, which is a platelet procedure which is quite different from the bloody PRP available through commonly used bedside centrifuges. To see a patient infographic on these differences, see this link for general info on the Regenexx-SCP platelet procedure and this one for a comparison between SCP and bedside PRP machines.

No. The Regenexx procedure involves isolating stem cells in a state of the art lab that’s part of a medical practice. Unlike centrifuge machine procedures that produce a “one size fits all” solution, the Centeno-Schultz clinic in Colorado uses cell biologists to get to much higher stem cell numbers than are possible with a bedside machine. The network doctors who have learned these techniques also process their samples by hand in mini-labs.

See all data published in peer reviewed medical journals on Regenexx procedures

In addition to peer reviewed publications, we also publish our treatment registry data online. See the most recent treatment registry data on Regenexx-SD for knee arthritis, hip arthritis analysis 1 and analysis 2 using different metrics, all shoulder patients, rotator cuff tear patients, ankle arthritis, and hand/wrist arthritis. In addition, low back sciatica outcomes on the Regenexx-PL-Disc procedure. Pre-publication data and before/after MRI case studies can often be found on the Regenexx blog.

No, they are simply your own adult stem cells. We only use autologous (your own) cells.

Cord stem cells are stem cells isolated from a baby’s umbilical cord. While they may be more biologically active because of their young age, recent research has suggested that they can also transmit genetic diseases that the baby may carry. Until these issues are further sorted out (likely with better genetic testing), We would advise against using any donor stem cells to treat non-life threatening disease. (cells from another person). This would include cord cells, embryonic stem cells, or someone else’s adult stem cells. To learn more about this topic, see this YouTube presentation produced by Dr. Centeno.

Yes,there are many types of adult stem cells. The most common is known as a hematopoetic stem cells (HSC-CD 34+). While these are easy to obtain from IV mobilized blood (where a special medicine is given to the patient first to push these cells out of the bone marrow) or bone marrow and are very plentiful. Outside of a handful of cardiac and vascular applications, they are not well studied as being effective in treating a broad range of diseases. Despite this, the vast majority of what you see being billed as “stem cells” from bone marrow (where the cells are injected the same day as collected) are these less useful cells. The type of adult stem cell that is most often seen in research as being associated with orthopedic tissue repair is a mesenchymal stem cell (MSC). MSCs can’t generally be harvested from blood. Fat tissue contains many MSCs, but these are distant cousins to the type obtained from bone marrow and aren’t as useful for orthopedic applications. For more more information on why stem cells from fat aren’t as useful as those from marrow to treat orthopedic injuries, click here. For an easy to understand patient infographic on why bone marrow stem cells are better than fat cells for orthopedic tissue repair, click here

Yes. For orthopedic applications, two main types of MSCs have been used, bone marrow derived and adipose (fat) derived. Bone marrow MSCs are taken via a needle through a bone marrow aspirate. The bone marrow aspiration procedure sounds like a big deal, but we are consistently told by patients that the procedure is very comfortable. The second type of MSC is derived from fat tissue (adipose). This can be obtained via liposuction. For orthopedic applications, fat derived MSCs consistently and dramatically under perform bone marrow derived cells. In studies of cartilage repair, bone repair, and soft-tissue repair, bone marrow derived MSCs are much more adept at these tasks. This makes sense, as they perform this function naturally (homologous) everyday. For example, if you break a bone, it’s these bone marrow MSCs that help mend that bone. In addition, for surgical micro fracture to repair small amounts of knee cartilage damage, it’s bone marrow MSC’s that are released to do that job.

Yes and No. First, many adipose stem cell clinics dramatically over-estimate the number of stem cells in their processed fat. This is a good hard core science review of the kits often used by physicians which over estimate these numbers. Basically, what physicians believe to be cells are actually small globs of fat tissue. Second, the proprietary Regenexx stem cell isolation method dramatically increases the number of stem cells isolated from bone marrow (based on our lab studies).

Still, on a weight to weight basis, fat can contain more mesenchymal stem cells than bone marrow, but the problem is that they just don’t work as well for orthopedic applications (click here for more information on this topic). In addition, in the Regenexx-AD knee stem cell procedure we offer the best of both worlds, bone marrow and fat.

For an easy to understand patient infographic on why bone marrow stem cells are better than fat cells for orthopedic tissue repair, click here.

Conditions Treated, Success Rates

Fractures that have failed to heal, joint cartilage problems, partial tears of tendons, muscles, or ligaments, chronic bursitis, avascular necrosis of the bone, and lumbar disc bulges.

Knee, hip, shoulder, ankle, hand, foot, elbow and spine.

Back and Neck

  • Lumbar facet injury
  • Herniated or bulging disc
  • Radiculopathy (pinched nerve)
  • SI Joint Syndrome
  • Cervical instability
  • Cervical facet injury
  • Neck, back or rib instability


  • Arthritis
  • Instability
  • Tennis Elbow or Golfer’s Elbow
  • Nerve entrapment (ulnar nerve)


  • Avascular Necrosis
  • Osteonecrosis
  • Bursitis
  • Arthritis
  • Tendinopathy
  • Labral / labrum tear


  • Arthritis
  • Patellofemoral Syndrome/Chondomalacia
  • Pes anersine bursitis
  • Baker’s cyst
  • Patellar tendonitis
  • Meniscus tear
  • MCL sprain or tear
  • ACL sprain or tear
  • PCL sprain or tear
  • LCL sprain or tear
  • Instability
  • Biceps Femoris Insertional Tendinopathy
  • Hamstrings Tendinopathy


  • Rotator cuff tears
  • Arthritis of the shoulder joint
  • Thoracic outlet syndrome
  • Labral tears or degeneration
  • Rotator cuff tendonitis
  • AC Joint Separation
  • Recurrent shoulder dislocations

Hand and Wrist

  • Hand Arthritis
  • Instability
  • TFCC tear
  • Carpal tunnel syndrome
  • Trigger finger

Ankle and Foot

  • Arthritis
  • Ankle Instability
  • Peroneal tendon tear or split
  • Ligament sprain or tear
  • Sub-talar arthritis or instability
  • Tarsal tunnel syndrome
  • Plantar fasciitis
  • Bunions

This depends quite a bit on the severity of the disease. We re constantly publishing case reports on our blog (often with before and after MRI images) which can usually be found at In addition, the blog will also feature scientific publications as they are published.

Click here for a list of our scientific publications

-Click here for an easy to understand patient infographic the Regenexx-SD (same day) procedure results.

-Click here for an Infographic comparing Regenexx-SD and Hip and Knee Replacement outcomes…

-Click here to see one on Regenexx-C results

-Click here to read about patient reports on:

-Knee, Hip, Shoulder and Rotator Cuff, Back and Disc, Ankle and Foot, Hand and Thumb, Avascular Necrosis

None have yet been completed, but we have three underway. The first involves rotator cuff tears, the second involves knee meniscus tears, and the third sciatica. For info on these trials, please contact our research director Patrick Reishling at

NO. All medical and surgical procedures have a success rate. This procedure is no different. We do see patients who do not respond. Please take a minute to review a more detailed discussion on this topic by clicking here. In addition, we have featured patient treatment failures on the blog.

As of April 2013 there have been more than greater than 2,000 bone marrow based (many patients receive multiple re-injections) and 3,000 platelet based procedures have been performed. We treated our first patients in 2005.

Marrow Aspirate

Patients often confuse a bone marrow aspirate with a more involved and more painful bone marrow biopsy. We only perform the less involved and much more comfortable bone marrow aspirate. Because we extensively numb the area, about 8 in 10 patients say that the marrow draw is very comfortable and would do it again. For more info on this topic, see

If you have a history of chronic low back pain, more discomfort can be expected. In that case, the doctor may offer you an epidural injection to better numb the area.

The skin and tissues are numbed, then a needle is used to draw a whole marrow aspirate and this is sent to the lab.

One skin site on each side will be numbed and three samples are taken from each of those sites.

If your hematocrit is below 30 or your hemoglobin is below 10, we may not be able to perform the procedure. If your hematocrit is between 30-36 or hemoglobin below 12, we may try to limit the IV blood or marrow draw amounts and will have you follow-up with your family doctor.

If you are under 110 pounds in weight, the doctor will likely decide to take less marrow or blood.

If your clotting times are normalized by taking clotting factors, then there should be no problem performing the procedure.

We generally recommend that you stop these before the procedure. For example, if you take Coumadin, you need to have the OK of your family doctor or cardiologist to come off this drug and an INR (blood clotting tests) that is in the normal range before pursuing this procedure. If you take other blood thinner such as Plavix, you should be off this drug for 72 hours prior to the procedure. Your family doctor or cardiologist may also need to be consulted to ensure that it’s safe to come off of this medication. If you take a daily baby aspirin, then you need to come off this one week before the procedure.

Blood Draw

A total of 50-200 cc may be drawn (about a few teaspoons less than 1/2 a pint). Less may be taken if you are under 110 pounds. See above. It’s also possible that more blood might be drawn if needed.

The growth factors that we use to grow your stem cells in culture are contained in your blood platelets.

Processing Stem Cells

The cells are isolated in the lab using a proprietary separation technique. For the same day procedure, this isolated stem cell fraction is placed right back into the body.

The Procedure

About as painful as a usual shot in a doctor’s office.

We use real time x-ray known as fluoroscopy or musculoskeletal ultrasound. Your MRI images are used to help plan that injection.


Everyone is different, but we recommend that you should have a ride home. It is advisable to take it easy for the day of the procedure. It is helpful to apply ice to the affected area. After the first day you can perform activity as tolerated or as instructed by your physician. You should be able to return to work the next day unless otherwise instructed by your physician.

The results should become apparent over 1-3 months, but sometimes can take as long as 6-9 months.

Some of our patients will require a second or even third procedure. Our usual protocol involves 1-3 injection cycles. Most patients get a single procedure.

Yes, we have developed our own supplement based on lab tests with human mesenchymal stem cells and their response to various nutritional supplements. Click here for more info.

This depends on the type of procedure. However, all of our procedures are designed to promote as much early activity as possible. Here is a general guide:
Bone healing procedure (for fracture non-union or avascular necrosis): You must be off the area on crutches until the pain from the procedure subsides. You can then move toward slowing increasing activities over the next few weeks. Total time off the area for most patients is 1-3 weeks with normal activities at about 6 weeks. The only exception is when there is an existing rod or plate stabilizing the fracture site, in these cases you will be allowed more activity more quickly.

Joint procedure. If there is more minimal cartilage loss, low impact activities would be encouraged immediately after the procedure. Full high impact activities would be expected at 4-6 weeks.

Partial tendon/ligament/muscle tear: Low impact activities would be encouraged immediately after the procedure. Full high impact activities would be expected at 4-6 weeks.

In general, we always try to look at more than one injured part. As a result, it’s very likely we will recommend other types of conservative care to restore normal biomechanics. This might include physical therapy, different types of myofascial release, or specific home exercises.

Yes, we ask that all patients either use a home infra-red unit or another type of ultrasound unit to help with cell growth. The infra-red unit is available through ActiveForever Medical Supplies

Most patients report an immediate pain relief due to the local anesthetic. This will last a few hours. Your pain may return and then continue to lessen over the next few days as the anti-inflammatory has time to work. You may also feel some discomfort at the treatment site which will subside quickly.

Insurance Coverage

We accept many PPO insurance plans with out of network benefits. Please call for more information.

NO. The procedure is too new to be covered yet by insurance.

If we are on your insurance network we will bill your carrier. If not, then there will be a consultation fee for the initial face to face consult.

Getting a Review of Films with a Clinic Doctor

The doctor can look at your films, history, and speak to you on the phone about if he or she believes this may help your problem. It’s important to note that this is not the formation of a traditional doctor-patient relationship until you see the doctor. Rather, this is just an opportunity for the doctor to determine if you’re a reasonable candidate for the procedure and for you to ask addition questions.
Realize that we currently place about 1/4 of the patients we see as GOOD candidates for the procedure, 1/2 as FAIR candidates, and 1/4 as POOR candidates. For more info on this, see

The charge is $200 for 15-30 minutes with the doctor. If you are determined to be a qualified candidate for the Regenexx-SD or Regenexx-AD procedures, this fee will be applied to the cost of the treatment. The fee is not applied to the cost of treatment for our platelet procedures: Regenexx-PL, Regenexx PL-Disc, or Regenexx-SCP.

The doctors prefer CD’s and not hard copies of actual films. These days, most imaging centers can easily and inexpensively burn a CD with the digital copies of your films. These can be sent to Regenerative Sciences, Inc at 403 Summit Blvd. Suite 201, Broomfield, CO 80020. We also provide a way to upload your imaging.

Please complete the Regenexx Candidate Form and you will receive complete instructions on the review process.


Using the HHS OHRP guidelines for complications reporting, our complications to date have been in the mild to moderate category and rare. This means that either the complication (like transient swelling) required no medical treatment (Mild), or if it did require medical treatment, the treatment was simple (Moderate-like a patient who failed the procedure who ultimately decided to get the knee replacement that he or she was planning before the procedure). We have published the world’s largest (to date) safety and complications tracking study of adult stem cell use in patients. This study did not show any serious stem cell related complications and it did not show that any patient developed a stem cell related cancer. In addition, our most recent safety paper was named the best of it’s type by a meta-analysis that appeared in the prestigious medical journal, Osteoarthritis and Cartilage.


Certain types of medications will negatively impact the stem cells. In addition, we generally see that many prescription medications will reduce stem cell number.

We produced the Regenexx Advanced Stem Cell Support Formula to support healthy stem cell function and cartilage production. Learn more or buy the supplement here.

The most commonly used non-steroidal anti-inflammatory drug (NSAID) medication is called TORADOL (ketorolac tromethamine). There are no known side-effects and without contraindications. Additionally, there is no evidence of the rebound effect (inflammation returning at a greater degree than prior to treatment) that is often times experienced when using steroids.

Stem Cell Lab(s)

Our lab is an extension of our medical practice. We only process cells in ISO-5 hoods (biologic safety cabinets) and these hoods are located in a lab with particle counts consistent with ISO-6.

We use nationally known lab accreditation companies. We periodically audit the lab and make any changes recommended by auditor.

Colorado has no tissue bank licensure. However, recently New York state asserted that we needed a New York tissue banking license to treat NY patients. While we disagreed with the general assertion that NY can regulate medical activities in Colorado, we did apply for such a license and did receive a license, which can be seen here.