Intervention Maps · Osteoarthritis · Hyaluronic acid
Do gel shots work?
Bottom line
Hyaluronic acid injections, often called gel shots, are widely offered for knee osteoarthritis. In large placebo-controlled trials, the average pain benefit is about the same as placebo, and serious side effects were more common. Guidelines disagree: some recommend against them, some say they are not for routine use, and some remain more open in certain knee situations. That disagreement isn't proof the joint was oiled, and it isn't proof the joint was repaired. This isn't PRP.
What this is
Hyaluronic acid is injected into the knee. The marketing story is that it restores joint fluid, like oiling a hinge. The evidence question is whether people feel less pain than they would after a placebo injection.
This page is about the knee. It isn't a steroid shot, not PRP, and not stem cells.
What the large trials show
A BMJ review that focused on large placebo-controlled trials found only a tiny average difference in pain, smaller than the change the reviewers treated as noticeable. Looking across the accumulating evidence, extra pain relief beyond placebo has looked absent since 2009.
Serious adverse events were more common with hyaluronic acid than with placebo.
That isn't a polite way of saying it works a little.
Guidelines do not agree
The main U.S. rheumatology guideline strongly recommends against hyaluronic acid. An orthopedic guideline advises it is not for routine use. An osteoarthritis research guideline is more permissive for some people with knee osteoarthritis and other health problems.
Those documents shouldn't be averaged into a consensus. Choosing the friendliest one doesn't change what the large trials found.
What taking part usually involves
- One injection or a short series into the knee, in clinic.
- Cost and access that vary widely, including whether insurance covers it.
- A follow-up that asks whether pain changed, not whether the joint was “relubricated.”
What this does not do
A gel shot hasn't been shown to repair cartilage or modify osteoarthritis as a disease. Looking like placebo for pain isn't evidence that the joint was repaired.
PRP is a different controversy. Don't treat “injections for osteoarthritis” as one class.
Evidence consulted Open sources
Key sources used to prepare this answer. This is not a citation for every sentence.
← Back to Osteoarthritis · find this again later from “What are you trying to figure out?”