IN SHORT
Bone marrow aspirate concentrate (BMAC) is your own bone marrow, drawn from the hip and concentrated, then injected the same day, usually into a joint. It can be legally offered in the US without FDA approval under a same-day exception, but evidence it works better than cheaper options is weak.
What is bone marrow aspirate concentrate (bmac)?
BMAC is a same-day treatment using your own bone marrow. The concentrate contains a small number of mesenchymal stromal cells, plus blood-forming cells, platelets and growth factors. It is different from a bone marrow transplant for cancer, which is an established treatment. BMAC is mostly marketed for joint and tendon problems.
How it works
Under local anaesthetic, a needle draws marrow from the back of the hip bone (iliac crest). The marrow is spun in a centrifuge to concentrate the cells. The concentrate is injected, often with ultrasound guidance, into the knee, hip, shoulder or tendon during the same visit. The whole procedure usually takes one to two hours.
Legal status
In the US, BMAC prepared and returned to the same patient during one procedure can fall under the FDA’s ‘same surgical procedure’ exception, so it does not need drug approval. Growing marrow cells in a lab, or sending them elsewhere for processing, would make them a drug needing approval. The exception does not mean the FDA has found BMAC effective. In the EU, minimally processed autologous marrow used in one procedure is generally outside medicines rules, while expanded cells are advanced therapies.
What the evidence shows
A 2017 trial gave 25 people BMAC in one arthritic knee and saline in the other; pain improved equally in both knees. Randomised trials in 2020 and 2025 found BMAC no better than PRP for knee arthritis. A 2026 network meta-analysis found BMAC improved pain more than hyaluronic acid, but not by a clinically meaningful amount. There is some evidence for BMAC in bone healing and as an add-on in cartilage surgery, but it is limited and mixed. There is no reliable evidence that BMAC injections regrow cartilage.
Commonly marketed for
- Knee and hip arthritis
- Rotator cuff and shoulder injuries
- Tendon and ligament injuries
- Back and disc pain
- Slow-healing fractures
- Add-on to cartilage or joint surgery
Cost
Typical price range: $1,150 – $12,000. A 2017 survey of 317 US clinics found stem cell knee injections, including bone marrow procedures, cost $1,150 to $12,000 (average $5,156). Insurance usually does not cover BMAC for arthritis.
Risks
- Pain and bruising at the hip harvest site
- Infection at harvest or injection site
- Post-injection joint pain or swelling
- Rare nerve or blood vessel injury during harvest
- High cost for benefit similar to cheaper injections
Questions to ask first
- Why BMAC rather than PRP or standard care, given trials show similar results?
- Is everything done in one procedure, or are my cells sent away for processing?
- How many cells are in the concentrate, and does dose matter for my problem?
- What are the total costs, including imaging and follow-up?
Before You Pay: The Stem Cell Clinic Checklist
- 20 questions every legitimate clinic should answer in writing
- A red-flag scorecard to spot unregulated marketing
- Realistic 2026 cost ranges: US, Mexico, Panama & Europe
- How to find a registered clinical trial
Bone Marrow Aspirate Concentrate (BMAC): FAQs
Is BMAC FDA-approved?
No. It can be offered legally without approval under a same-day exception, but the FDA has not found it effective for any condition.
Does BMAC regrow cartilage?
There is no reliable evidence that it does. Trials mainly measure pain and function, with modest results.
Is the bone marrow harvest painful?
It is done under local anaesthetic, but many people feel pressure and some soreness for days afterwards.
Is BMAC better than PRP?
Randomised trials in 2020 and 2025 found it no better than PRP for knee arthritis, while being more invasive and more expensive.
Is BMAC the same as a bone marrow transplant?
No. A bone marrow transplant replaces the blood and immune system, mainly for cancers. BMAC is a local injection of concentrated marrow.
Related guides
- IV Stem Cell Therapy
- Mesenchymal Stem Cells (MSCs)
- Umbilical Cord Stem Cells
- Placental & Amniotic Stem Cell Products
- Exosome Therapy
- All treatment types · Glossary
Sources
- A prospective, single-blind, placebo-controlled trial of BMAC for knee osteoarthritis (Am J Sports Med, 2017)
- BMAC is equivalent to PRP for knee osteoarthritis at 1 year: randomized trial (2020)
- RCT confirms non-superiority of bone marrow aspirate compared to PRP in knee osteoarthritis (2025)
- Intra-articular orthobiologics: network meta-analysis of RCTs (Arthroscopy, 2026)
- AAOS: Technology overview — concentrated bone marrow aspirate for knee osteoarthritis
- FDA: Regulatory considerations for HCT/Ps — minimal manipulation and homologous use (2017 guidance)
- Stem cell centers on the rise (AAOS cost survey)
Last reviewed October 2026. For general information only — not medical advice. We do not endorse any clinic or product. Always consult a qualified, licensed healthcare professional. See our medical disclaimer and editorial policy.