Prolotherapy Research
Please visit The Journal of Prolotherapy

Before double-blinded studies, doctors would ask patients if they felt better. If patient after patient told the physician they felt better, than it was presumed and accepted that the therapy was effective. If it was a new therapy, then it was taught doctor to doctor and eventually it was taught in medical schools. If this was still the standard upon which medical therapies were judged, then clearly Prolotherapy would be taught in all the medical schools, but it is not. Why not?

Modern allopathathic medical research demands that therapies be proven by double-blinded methods. This means that neither the patient nor the physician knows which therapy is used. For medications this is easy because the pills can be made to look alike and a sugar pill used as the placebo is presumed to have no therapeutic value. Unfortunately for certain procedures, like Prolotherapy and most surgeries, there is no adequate placebo. 

Prolotherapy involves multiple Prolotherapy injections (watch where do Prolotherapy injections go and do they hurt?) into the ligament/bone interface and joints where a person is experiencing pain. Prolotherapy induces a mild inflammatory reaction that helps proliferate fibroblasts which make the collagen tissue which makes up ligaments, tendons, and most joint tissue.

Once enough collagen is made, that ligament, tendon, or joint structure will improve its strength enough to eliminate the person's pain. Current researchers  typically use  saline solution as a placebo in Prolotherapy studies instead of one of the ‘normal’ Prolotherapy solutions. 

In other words, the technique of the Prolotherapy injections versus the placebo injections is exactly the same. The placebo injections involve piercing the skin and injecting the saline solution into the bone/ligament interface or into the respective joints. The problem with this method is that sticking needles into areas of pain as the placebo, is not a placebo, it is called acupuncture. It has been shown that just dry needling an area of pain can help diminish or eliminate the pain.1  Acupuncture is an accepted medical treatment.

On top of that, to diminish the pain of the Prolotherapy shots, researchers will often inject lidocaine or anesthetics into the skin, but this again is an active treatment for pain.  Intradermal injection (injection into the skin) is another method practitioners can use to eliminate pain. Another fact is that saline injections into areas of pain is also an effective therapy to eliminate pain. For example, in a controlled, double-blind comparison of mepivicaine injection versus saline injection for Myofascial pain, the group receiving saline tended to have more relief of pain, especially after the first injection. In this study, 28 patients with acute, localized muscle pain received four local injections of mepivicaine (anesthetic) and 25 patients with the same type of pain received local injections of an equivalent volume of physiological saline. Considerable improvement or freedom from symptoms was reported in 48% of patients treated with physiological saline and 42% in the mepivicaine group. 

The conclusion was that physiological saline is considered to be a more appropriate fluid for injection therapy than local anaesthetics since it is less likely to produce side-effects. The study, therefore, raises questions about the mechanism by which local injections into muscles relieves pain, since there is the possibility that a similar effect might also be achieved by merely inserting a needle into the trigger point.2 One wonders if the reason saline helps with muscle pain is because it induces a mild inflammatory reaction. Such a reaction deems the therapy then Prolotherapy. There have been other studies also to show the pain-reducing effects of saline or just plain sterile water injections.3,4 Also, what worse back pain can there be than labor pain? Subcutaneous injections of sterile water into the area of back pain in women in labor can significantly reduce their pain.5,6,7  

In summary, sticking a needle through the skin eliminates pain (acupuncture), sticking a needle through muscles eliminates pain (dry needling), sticking a needle into the skin and injecting water into it eliminates pain, and saline injections into muscles eliminates pain. So if one was to do a Prolotherapy study it would be impossible to have a placebo group because the placebo group even if they were injected with nothing would still be getting a treatment that eliminates pain. See Prolotherapy (more information at Prolotherapy.org)

1. Garvey, T. A prospective, randomized, double-blind evaluation of trigger point injection therapy for low back pain. Spine. 1989; 14: 962-964.
2. Frost, F. A control, double-blind comparison of mepivicaine injection versus saline injection for myofascial pain. The Lancet. 1980; March 8, pp. 499-501. 
3. Jenson, M. Improved patient compliance after trigger point injections using a 0.9% sodium chloride compared to bupivacaine 0.025% for patients with myofascial pain syndrome. The Pain Practitioner. 2001; Fall, pp. 4-6.
4. Byrn, C. Subcutaneous sterile water injections for chronic neck and shoulder pain following whiplash injuries. The Lancet. 1993; 341: 449-452.
5. Trolle, B. The effect of sterile water blocks on low back pain labor pain. Am J Obstet Gynecol. 1991; 164: 1277-81.
6. Ader, L. Parturition pain treated by intracutaneous injections of sterile water. Pain. 1990; 41: 133-8.
7. Byrn, C. Subcutaneous sterile water injections for chronic neck and shoulder pain following whiplash injuries. The Lancet. 1993; 341: 449-452.