What Happens During a Stem Cell Procedure, Step by Step
Most patients arrive on the day without a clear picture of what will happen. Here is the sequence, with the questions worth asking at each stage.
1. Consultation and imaging
What happens: history, examination, and usually imaging — MRI or ultrasound for joints, X-ray for arthritis staging. The clinic assesses whether you are a candidate and proposes a treatment plan.
Time: 1–2 hours. Cost: $800–$2,500 in the US, often free or credited overseas.
Ask: Is my diagnosis confirmed? Am I a candidate for the conventional treatments first? What exactly are you proposing, and what does it cost in total, itemised?
2. Pre-procedure preparation
What happens: blood tests, instructions to stop anti-inflammatory medication — typically NSAIDs for one to two weeks, since they may interfere with the intended effect — and sometimes to stop blood thinners under medical supervision.
Ask: What must I stop, when, and who is checking that stopping it is safe for me?
3. Harvest (autologous treatments only)
Bone marrow. You lie face down. The skin over the back of the pelvis is numbed. A needle is passed through into the marrow cavity and aspirate drawn, often from several sites. Most patients describe pressure rather than sharp pain, though the moment of aspiration is uncomfortable. Takes 30–45 minutes.
Fat. A mini-liposuction, usually from the abdomen or flank, under local anaesthetic with light sedation. 30–60 minutes.
If you are receiving a donor cord product, this step does not happen.
Ask: Who performs this? How much will you collect, and what yield do you typically get from someone my age?
4. Processing
What happens: the sample goes to an on-site lab. It is centrifuged to concentrate the cell fraction, sometimes filtered or washed. In most same-day clinic treatments there is no culture expansion — cells are concentrated, not grown.
Time: 45–90 minutes, usually while you wait.
Ask: How many viable cells will I receive, and how is viability measured? May I see the count for my sample?
This is the most revealing question in the whole process. A clinic that measures and tells you is operating differently from one that does not.
5. Delivery
Joint injection. Under ultrasound or fluoroscopic guidance, the concentrate is injected into the joint. Takes 10–20 minutes. Mildly uncomfortable.
Intradiscal injection. Under fluoroscopic or CT guidance into the disc. More involved, more uncomfortable, more risk.
Intravenous infusion. A drip over 30–60 minutes. Used for systemic conditions — and the route with the weakest rationale for reaching joints or nerves, since most infused cells are cleared by the lungs within hours.
Ask: What imaging guidance is used, and who performs the injection?
6. Immediately after
Observation for 30–60 minutes, then discharge. You will usually need someone to drive you if sedation was used.
Expect soreness at the harvest and injection sites for several days. A temporary flare of joint pain in the first week is common and expected.
7. Recovery and follow-up
Most clinics advise avoiding anti-inflammatory medication for a period afterwards, relative rest for a few days, then a graded return to activity. Physical therapy is often recommended — and is worth taking seriously, since it has evidence of its own.
Assessment usually happens at 6 weeks, 3 months and 6 months. Clinics typically describe change developing over 6–12 weeks rather than immediately.
Ask: What outcome measure will you use to assess whether this worked, and at what points?
The whole day
For a same-day autologous joint treatment: arrive in the morning, harvest, wait during processing, injection early afternoon, home by mid-afternoon. Roughly 4–6 hours.
One thing to notice about the sequence
Steps 3 to 5 are not exotic. A marrow aspiration, a centrifuge run, and an ultrasound-guided injection are routine procedures. That is worth holding in mind against a $12,000 price — much of which reflects marketing and margin rather than the complexity of the day. See where the money goes.
Sources
- International Society for Stem Cell Research — Patient Handbook on Stem Cell Therapies.
- US Food and Drug Administration — Regulatory Considerations for Human Cells, Tissues, and Cellular and Tissue-Based Products.
- Contextual effects of mesenchymal stem cell injections for knee osteoarthritis: systematic review and meta-analysis of RCTs. Frontiers in Medicine, 2025.
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Medical disclaimer
This article is for general information and is not medical advice. We are not a healthcare provider and do not diagnose or treat any condition. Most stem cell treatments discussed here are not FDA approved for these uses, outcomes vary, and no result is guaranteed. Always speak with a licensed physician who knows your history. See our medical disclaimer and how we make money.