BPC-157 Knee Study (2021): Results and Limitations

Written by BPC-157 Research TeamEvidence checked 23 September 2026

A 2021 study looked back at the records of people who had received BPC-157 injections into the knee for knee pain at a Florida clinic. Most of those contacted afterwards reported improvement, but the study had no placebo or untreated comparison group and relied on a telephone survey, so it cannot show that BPC-157 caused the improvement.

Why does this study matter?

This is one of only three full published reports of BPC-157 use in humans, and the first to describe injections into a joint. Its retrospective design means it provides much weaker evidence than a randomised controlled trial, but it remains part of the small human record.

What were the researchers trying to find out?

Whether patients who had received BPC-157 injections into the knee, for several different causes of knee pain, felt their pain had improved afterwards.

How was the study carried out?

The researchers reviewed one year of charts (2019 to 2020) at a single clinic and then telephoned patients to ask about their knee pain. Of the 17 patients identified, 16 were reached. Twelve had received BPC-157 alone and four had received BPC-157 together with another peptide, thymosin beta-4. Patients were asked to rate their pain before the injection, how long any relief lasted, and how much the injection had helped. No standard questionnaires were used to measure function or quality of life.

What did the study report?

The authors reported that 11 of the 12 patients who received BPC-157 alone described significant improvement in their knee pain, and one reported no improvement. Of the four who received both peptides, three reported improvement. Overall, the authors reported improvement in 14 of the 16 patients contacted.

These are the authors' reported figures. Because there was no comparison group, they describe what patients said afterwards, not what BPC-157 did.

What did it report about safety?

The published report did not describe systematic safety monitoring or adverse-event reporting. A study of this size and design cannot establish the safety of BPC-157 or detect uncommon side effects. Our BPC-157 side effects guide covers what has and hasn't been documented.

What can we conclude?

The study shows that BPC-157 has been injected into human knees in a clinic setting and that most patients contacted afterwards said their pain had improved. It cannot show that BPC-157 caused the improvement, because knee pain often improves on its own, placebo effects are strong in pain conditions, and there was no group to compare against.

What are the study's limitations?

• No comparison group. Without one, it is difficult to say how much change was due to BPC-157 rather than natural recovery, placebo effects or other care.
• Small size. Sixteen people cannot reliably detect uncommon side effects or show whether results apply more widely.
• Looking backwards. The researchers reviewed past treatment rather than planning the study in advance, which makes the results easier to bias.
• No standard measurements. Pain and improvement were self-rated over the phone, without validated questionnaires.

How does this fit with other BPC-157 human research?

This is one of three recent full published human reports identified in our review, all sharing the same first author and journal. The wider human record also includes registered clinical trials and earlier studies reported only as abstracts. View all BPC-157 clinical trials and human studies →