The answer so far
A small rabbit study found lower cartilage-damage scores after AOD-9604, particularly when combined with hyaluronic acid. That is a reason to study the idea, not proof that it regrows cartilage or treats osteoarthritis in people. Human pain, function, safety and lasting repair need their own evidence.12
On this page
- What is cartilage, and what is osteoarthritis?
- Where does the cartilage-repair claim come from?
- What did the rabbit study find?
- Does a better score show cartilage regrew?
- Has it been shown to repair a person’s joint?
- What is hyaluronic acid doing in the comparison?
- Can the rabbit result tell us about another product or route?
- What should someone with joint pain consider?
- Sources
Can AOD-9604 repair cartilage or help an arthritic knee? Choose a step to explore this subject in more detail.
What is cartilage, and what is osteoarthritis?
Cartilage is smooth, resilient tissue covering the ends of bones in a joint. Osteoarthritis involves changes to cartilage and other joint tissues; pain and stiffness are not simply a direct readout of how much cartilage remains. Different problems—including injury, inflammation, gout and infection—can cause joint pain. A proper assessment asks what is happening in the person, not just what appears in a product advertisement.34
Where does the cartilage-repair claim come from?
AOD-9604 is a synthetic peptide related to a fragment of growth hormone. A 2015 study looked at its effect, alone and with hyaluronic acid, in rabbits with experimentally induced knee damage. The researchers compared four equal groups: saline, hyaluronic acid, AOD-9604 and their combination. Each group had eight rabbits. The peptide was administered into the experimental knee joint; that does not establish the effects of a different preparation, location or route. For its separate weight-loss story, see the AOD-9604 human weight study.1
What did the rabbit study find?
The researchers examined the joint surfaces and tissue under a microscope, assigning scores for damage, and observed how long the animals limped. The AOD-9604 group had lower damage scores than the saline group. The combination group had lower scores than either ingredient alone and a shorter observed lameness period. The tissue assessors and lameness observers did not know the treatment groups. These are interesting findings in a small, experimentally injured animal model; they are not measurements of a person’s pain or mobility.1
- 32 rabbitsFour groups of eight had experimentally induced knee damage.
- Four comparisonsSaline, hyaluronic acid, AOD-9604, or AOD-9604 plus hyaluronic acid.
- What was measuredObservers recorded lameness; joint surfaces and tissue were scored for damage.
- What remains unknownThe findings do not establish human pain relief, lasting repair or safety.
Does a better score show cartilage regrew?
The authors described their findings as cartilage regeneration. Their measurements show differences in damage scores at the time of assessment, but they do not establish how much new cartilage grew rather than damage being reduced. Nor do they demonstrate durable repair in people. The report also contains inconsistencies: its abstract describes both knees and an eight-week assessment, while its methods describe the right knee and assessment after nine weeks. These details make replication harder to interpret, even though the comparison and reported results remain relevant.12
Has it been shown to repair a person’s joint?
Human joint repair is not established by that experiment. In a 2024 briefing, the US FDA said it had not identified clinical studies of AOD-9604 in people with osteoarthritis or osteoporosis in its literature search. It did not assess whether those nominated uses were appropriate because the submitted information was insufficient. This is a dated description of the regulator’s search, not a claim that every possible later or unpublished study is known. Human studies would need defined products and comparisons, pain and function outcomes, appropriate imaging or tissue measures, and safety follow-up.21
What is hyaluronic acid doing in the comparison?
Hyaluronic acid is a substance found in joint fluid and other tissues; products containing it have been used in some knee osteoarthritis treatments. It is not AOD-9604 and is not a steroid. Recommendations for hyaluronic acid injections alone differ: the UK NICE guideline advises against offering them for osteoarthritis, while US NIAMS notes they are sometimes recommended; the US AAOS guideline does not recommend routine use for symptomatic knee osteoarthritis. None of these statements establishes that adding AOD-9604 works or that cartilage will regrow.456
Can the rabbit result tell us about another product or route?
No. The animal study used a defined experimental preparation in the joint. It cannot show what an oral, topical or under-the-skin product does, where it travels or whether it reaches a joint at an effective concentration. The FDA’s 2024 review also described limited safety information for proposed routes. An online label cannot prove identity or sterility. See what a peptide certificate of analysis can and cannot show and the AOD-9604 overview.21
What should someone with joint pain consider?
Persistent or recurring joint pain deserves an assessment of the possible cause and the activities affected. Care may include education, suitable movement or physiotherapy, pain management and, for some people, procedures; it depends on the diagnosis and individual circumstances. A suddenly painful, swollen or hot joint—especially with difficulty moving it or feeling unwell—needs urgent medical assessment because an infection is one possible cause; fever is not always present. For a different peptide and a separate human report, read what the BPC-157 knee study did and did not show, or visit joints and recovery.47
Sources, kept close.
Selected supporting sources; this is not a complete literature review.
- Effect of intra-articular AOD9604 with or without hyaluronic acid in a rabbit osteoarthritis modelAnnals of Clinical & Laboratory Science · Primary animal study, 2015
- AOD-9604 related bulk drug substances: FDA advisory committee briefingUS Food and Drug Administration · 2024 US regulator briefing; obesity evaluation and search limitations
- OsteoarthritisNational Institute of Arthritis and Musculoskeletal and Skin Diseases · US public-health overview
- Osteoarthritis: diagnosis, treatment, and steps to takeNational Institute of Arthritis and Musculoskeletal and Skin Diseases · US public-health clinical overview
- Osteoarthritis in over 16s: diagnosis and managementNational Institute for Health and Care Excellence · England guideline NG226, 2022
- Management of osteoarthritis of the knee, non-arthroplastyAmerican Academy of Orthopaedic Surgeons · US professional guideline, 2021
- Septic arthritisNHS · UK public-health guidance