What Is Prolotherapy, and Does It Work?

Prolotherapy is a series of injections of an irritant solution, most often concentrated dextrose (sugar water), into a painful ligament, tendon, or joint. The idea is that a brief, local inflammatory response prompts the body's own repair processes. The best evidence is for knee osteoarthritis, where two randomized trials found larger improvements than saline injections at one year (Rabago et al., 2013; Sit et al., 2020). Evidence for other areas is limited or mixed, and Medicare does not cover it (Centers for Medicare & Medicaid Services [CMS], 1999).

What This Means

Prolotherapy has been used for decades under several names, including proliferant injection, sclerotherapy of joints, and regenerative injection therapy. The solution is usually hypertonic dextrose mixed with a local anesthetic such as lidocaine. Both knee trials described below used a 25% dextrose solution inside the joint (Rabago et al., 2013; Sit et al., 2020).

It is not a single injection. Published protocols repeat the injections every four weeks or so over several months. It is also not a stem cell or platelet product: nothing is taken from your blood or tissue. At PrimeCell Regenerative, prolotherapy is described as an off-label use with limited evidence, and we say so before anyone agrees to it.

Candidacy

The adults in the strongest trials had painful knee osteoarthritis, meaning wear-related changes in the knee joint; in one trial, pain had lasted at least three months (Rabago et al., 2013; Sit et al., 2020). Research on chronic low back pain and hand osteoarthritis exists but is smaller and less consistent (Rabago et al., 2005).

Candidacy is a physician's decision after an evaluation. Prolotherapy is usually a poor fit when the pain source is unclear, when there is an active infection near the injection site, or when symptoms suggest a problem that needs urgent imaging or surgical review.

Clinical Evaluation

An evaluation at PrimeCell Regenerative includes a history, a musculoskeletal and neurological exam, a review of prior imaging, and ultrasound imaging when appropriate. Knee pain alone has several possible sources: osteoarthritis, a meniscus problem, patellar tendinopathy (irritation of the tendon just below the kneecap), or pain referred from the hip. I want to know which structure is generating the pain before recommending anything.

Available Options

For knee osteoarthritis, the mainstream options come first: exercise and physical therapy, weight management where relevant, activity changes, bracing, and oral or topical medication when appropriate. Injection options include corticosteroid, hyaluronic acid, platelet-rich plasma (PRP), and prolotherapy, each with different evidence, cost, and timelines. For how PRP compares with cortisone, see PRP vs Cortisone Injections: Which Fits?

Which option makes sense depends on the exam, the imaging, what has already been tried, and your goals. Individual results vary.

Benefits, Limitations and Risks

Dextrose is inexpensive, widely available, and not derived from donor tissue. In the knee trials, no adverse events were reported beyond expected procedure discomfort (Rabago et al., 2013; Sit et al., 2020).

The limitations are real. It takes several visits over months. Injection-site pain and irritation for a few days afterward are common (Rabago et al., 2005), and one trial prescribed short-term pain medication for that reason (Rabago et al., 2013). Any injection carries a small risk of bleeding, infection, or nerve irritation. Because Medicare and most insurers do not pay for it, the cost is out of pocket (CMS, 1999).

What the Evidence Shows

Knee osteoarthritis. In a blinded trial of 90 adults, those who received dextrose injections improved 15.3 points on the 100-point WOMAC osteoarthritis score at 52 weeks, compared with 7.6 points for saline injections and 8.2 points for at-home exercise, a difference that exceeded the score's minimal clinically important difference (Rabago et al., 2013). A second blinded trial of 76 adults in Hong Kong found WOMAC pain scores improved about 10 points more with intra-articular dextrose than with saline at 52 weeks (Sit et al., 2020). Both trials were small and single-center.

Other conditions. A systematic review of six randomized trials (439 adults) found mixed results for chronic low back pain. Two trials that combined injections with other care, such as spinal manipulation and exercise, found benefit; two others, including one that tested injections alone, did not. The authors concluded that the small number of high-quality studies did not allow firm conclusions (Rabago et al., 2005).

What it does not establish: these studies do not show that prolotherapy rebuilds cartilage or ligaments, and they do not show that results from knee studies apply to other joints. Medicare's national coverage policy states that the medical effectiveness of prolotherapy has not been verified by scientifically controlled studies (CMS, 1999). That policy dates to 1999 and predates both knee trials, but it has not changed.

Recovery and Next Steps

Most people return to normal daily activity the same day, with soreness at the injection site for a few days. Published protocols space sessions roughly four weeks apart and judge results over months, not days. If a series is not producing a meaningful change after the planned number of sessions, that is a reason to stop and reassess, not to keep adding injections.

If you are considering prolotherapy, bring prior imaging and a list of what you have already tried to an evaluation. Ask how many sessions are planned, what the total cost will be in writing, and how progress will be measured.

Orlando Considerations

Prolotherapy does not involve stem cells. The Florida stem cell notice shown on this page applies to other therapies offered at the practice, not to prolotherapy. Because Medicare's national policy excludes it (CMS, 1999), Orlando-area patients on Medicare should expect to pay privately and can ask for a written estimate before the first session. For more on coverage, see Does Medicare Cover Regenerative Medicine?