Prolotherapy is an injection-based treatment for chronic joint and tendon pain. A sugar solution, typically dextrose, is injected directly into damaged or painful connective tissue to trigger a controlled inflammatory response that stimulates the body’s own repair process. The name comes from “proliferation therapy,” referring to the growth of new tissue at the injection site.
How Prolotherapy Works
The core idea is counterintuitive: prolotherapy creates a small, deliberate injury to jumpstart healing in tissue that has stopped repairing itself. Dextrose, a simple sugar, is injected at concentrations between 12.5% and 25%. At these levels, the solution dehydrates cells at the injection site, causing localized cell death. This triggers a cascade of events that mimics the body’s normal wound-healing response.
First, the damaged cells release chemical signals that recruit immune cells to the area. Those immune cells, in turn, attract fibroblasts, the cells responsible for building connective tissue. The fibroblasts lay down new collagen at the injection site, and over weeks, that collagen matures and contracts. The end result is tighter, stronger ligament or tendon tissue. This matters because chronic tendon and ligament problems often involve tissue that has partially broken down and failed to rebuild on its own.
Conditions It Treats
Prolotherapy is primarily used for chronic musculoskeletal pain that hasn’t responded to standard treatments like physical therapy, bracing, or oral pain medication. The three conditions with the most research behind them are low back pain, osteoarthritis, and tendinopathy.
Tendon conditions have the strongest evidence. Studies have evaluated prolotherapy for lateral epicondylosis (commonly called tennis elbow), Achilles tendinopathy, hip adductor injuries, and plantar fasciitis. These are all overuse injuries where the underlying problem is degenerated tendon tissue rather than acute inflammation.
Prolotherapy has also been studied for knee osteoarthritis (including cases with ligament laxity), sacroiliac joint dysfunction, and other conditions involving loose or weakened connective tissue. During a session, injections target the specific spots where ligaments and tendons attach to bone, as well as the joint space itself, with the goal of improving joint stability and reducing pain.
What a Treatment Session Looks Like
The dextrose solution is commercially available at 50% concentration and diluted with saline or sterile water to reach the target strength. For comfort, a local anesthetic is often applied at the skin before the deeper injections. The practitioner then injects small amounts of the solution at multiple points around the painful area, guided by anatomical landmarks or imaging.
Treatment protocols vary depending on the condition and severity. Some patients receive a single injection, while others undergo a series of three or four sessions spaced three to four weeks apart. Research protocols have ranged from one session to four sessions at monthly intervals, with three sessions at three-week intervals being one of the more common approaches. Your practitioner will typically reassess your pain and function between visits to decide whether additional sessions are needed.
Recovery and Side Effects
You can generally return to normal activities shortly after the injection, though you should expect some soreness and stiffness at the site for up to 10 days. Temporary numbness from the anesthetic wears off within a few days. Some people experience mild flu-like symptoms or a rash for a day or two afterward.
Ice can help with swelling and discomfort. Place a cold pack wrapped in a towel over the injection site for 15 to 20 minutes at a time. One important detail: you should avoid anti-inflammatory medications like ibuprofen and naproxen after the procedure. Since prolotherapy works by deliberately triggering inflammation, suppressing that response with NSAIDs could undermine the treatment’s purpose. Acetaminophen (Tylenol) is typically a safer choice for managing post-injection pain.
Serious complications are rare. The primary risks are a slight chance of skin infection at the injection site and the possibility of an allergic reaction to the sugar-based solution.
How It Compares to PRP
Platelet-rich plasma (PRP) therapy is the other major injection-based regenerative treatment, and the two are frequently compared. PRP uses a concentrated sample of your own blood platelets, which contain growth factors that promote healing. Prolotherapy uses a simple sugar solution instead.
In a study comparing the two treatments for ankle cartilage lesions, outcomes were essentially equivalent. About 89% of prolotherapy patients and 91% of PRP patients reported excellent or good results at one-year follow-up, with no statistically significant difference between the groups. Prolotherapy’s main practical advantages are lower cost and a simpler preparation process, since PRP requires a blood draw and centrifuge processing.
Cost and Insurance Coverage
Prolotherapy is almost always an out-of-pocket expense. Major insurers, including UnitedHealthcare, classify it as “unproven and not medically necessary” due to what they consider insufficient evidence, and Medicare does not cover it. This classification means you will likely pay for the full cost yourself.
Exact pricing varies by provider, geographic area, and the number of injection sites treated per session. The American Association of Hip and Knee Surgeons has noted the “high out-of-pocket costs” as a barrier for patients. Because a full course of treatment often involves multiple sessions, the total expense can add up. It’s worth asking your provider about per-session costs upfront and how many sessions they anticipate you’ll need.
What the Evidence Shows
Prolotherapy sits in a complicated place in medicine. It has decades of clinical use and a growing body of research, but the evidence is uneven across conditions. For chronic tendon problems, the data is the most convincing, with multiple randomized controlled trials showing benefit over control injections. For osteoarthritis and low back pain, results are more mixed, partly because study designs have varied widely.
One challenge in studying prolotherapy is choosing the right comparison group. Many trials have compared dextrose injections to saline injections, but saline itself may have some therapeutic effect when injected into tissue, which can make dextrose look less impressive than it might be compared to no treatment at all. This is an ongoing debate that complicates the interpretation of clinical trials. Despite the insurance industry’s stance, many pain specialists and sports medicine practitioners consider prolotherapy a reasonable option for patients who haven’t improved with conventional care.