What about PRP? Is it the same as a gel shot?

What this is

Platelet-rich plasma is made from a person's own blood and injected into the knee. Clinics often describe it as regenerative. The evidence question is whether pain and function improve compared with a placebo injection.

It isn't hyaluronic acid. In large gel-shot trials, pain relief looks about the same as placebo. PRP's debate is different: some trials show a benefit versus placebo, while a major guideline still recommends against it. Don't treat them as the same kind of shot.

What the placebo-controlled trials show

A 2025 review of 18 trials found that, at some follow-up times, pain and function improvements could exceed the change the reviewers treated as noticeable. The clearer signals were concentrated in preparations with higher platelet concentrations. Lower-platelet products often did not show the same pain results.

That means the placebo-controlled signal shouldn't simply be dismissed. It isn't enough to call PRP a joint repair, and it isn't enough to treat the rheumatology guideline as silently retired.

Guidelines still disagree

The main U.S. rheumatology guideline still strongly recommends against PRP. An orthopedic guideline offers a limited recommendation in favor.

Both facts belong together. Averaging the two societies doesn't settle the question.

What taking part usually involves

• A blood draw, processing in clinic, and an injection into the knee.
• Products that may not match the higher-platelet preparations that drove more of the trial benefit.
• Cost that is often out of pocket.

If a clinic can't say how the product compares with what was studied, the trial numbers don't automatically transfer.

What this does not do

PRP hasn't been shown to regenerate cartilage, change the joint on imaging, or delay replacement. This evidence also hasn't been shown to apply to the hip.

Stem cell injections are a different story. “Regenerative shots” isn't one treatment.