Stem cell therapy and PRP are both injections made from your own body that aim to ease joint pain, but they work differently. PRP uses concentrated platelets to calm inflammation, while stem cell therapy uses cells from bone marrow or fat that aim to support tissue repair. Neither is proven to regrow lost cartilage. PRP is simpler and more affordable, stem cell therapy is more complex and costlier, and results for both vary from person to person.
PRP: a concentrate of your own platelets and growth factors, drawn from a simple blood sample, mainly used to reduce pain and inflammation in mild to moderate arthritis and soft tissue injuries
Stem cell therapy: cells usually taken from bone marrow or fat tissue, used for early to moderate arthritis, with evidence for knee osteoarthritis that is still developing
Key differences: procedure complexity, cost, and how long relief may last, with PRP being the simpler option and stem cell therapy the more involved one
Severe damage needs a different plan: when the cartilage is gone, knee replacement is the proven option rather than either injection
Stem Cell Therapy vs PRP: Key Differences at a Glance
The main difference is what each injection contains. PRP (platelet-rich plasma) is a concentrate of platelets and growth factors from your blood, which mainly helps calm inflammation and pain. Stem cell therapy uses cells, usually from your bone marrow or fat, which are being studied for their ability to support tissue repair. The table below compares them side by side.
Stem cell therapy vs PRP for joint pain and arthritis
Factor
PRP Therapy
Stem Cell Therapy
What it is
Concentrated platelets and growth factors from your own blood
Cells taken from your own bone marrow or fat tissue and concentrated for injection
How it works
Releases growth factors that help reduce inflammation and pain
Cells and the signals they release may help modulate inflammation and support tissue repair
Best suited for
Mild to moderate arthritis, tendon and ligament injuries
Early to moderate arthritis, especially when PRP has not given enough relief
Procedure
Simple blood draw, spun in a centrifuge, then injected. Usually under an hour
Bone marrow or fat collection, processing, then injection. Takes longer and is more involved
Downtime
Minimal. Most people resume light activity within a few days
Short, but the collection site may be sore for a few days
How long relief may last
Often several months to around a year, varying by person
Some studies report longer relief, but results vary and long-term data is limited
Cost
Generally lower
Generally higher
Strength of evidence
More studies, with mixed but encouraging results for knee osteoarthritis
Promising, but still developing and less standardized
PRP (platelet-rich plasma) therapy is an injection made from your own blood. A small blood sample is spun in a centrifuge to concentrate the platelets, which carry growth factors involved in healing. The concentrate is then injected into the painful joint, tendon or ligament. It is mainly used to reduce pain and inflammation, and it is not a cure for arthritis.
How PRP Therapy Works
Platelets are best known for helping blood clot, but they also release proteins that influence inflammation and tissue healing. In PRP, the platelet count is raised well above what is found in normal blood. Placing this concentrate in an irritated joint is thought to calm inflammation and may support the body's own repair signals. How well it works varies from person to person.
How the PRP Procedure Is Done
Blood draw: a small amount of blood is taken from your arm, similar to a routine blood test.
Processing: the blood is spun in a centrifuge to separate and concentrate the platelets from other blood components.
Preparation of the area: the skin is cleaned and, in many cases, numbed with a local anesthetic.
Injection: the PRP is injected into the joint or injured tissue, often guided by ultrasound for accuracy.
Rest and review: you can usually go home the same day, with a follow-up to check how you respond.
Who May Benefit from PRP
May be a good fit
Mild to moderate knee osteoarthritis
Tendon problems such as tennis elbow
Ligament and some sports injuries
People wanting a low-downtime option before considering surgery
May not be suitable
Severe arthritis with little or no cartilage left
Blood disorders or low platelet counts
Active infection near the injection site
Those on blood thinners, unless their doctor advises otherwise
What to Expect After PRP
Soreness or swelling at the injection site is common for a few days. Because the injection uses your own blood, allergic reactions are uncommon, though infection, bleeding and temporary pain flare-ups are possible. Improvement is usually gradual over several weeks rather than immediate, and some people need more than one injection. Relief may last from a few months to around a year, and results are not guaranteed.
Good to know: PRP can ease symptoms but does not reverse advanced joint damage. If your cartilage is badly worn, knee replacement may be the more reliable option, and a partial replacement may suit you if only part of the knee is affected. You can also compare PRP with stem cell therapy for knee osteoarthritis.
What Is Stem Cell Therapy?
Stem cell therapy for joints is an injection of concentrated cells, usually taken from your own bone marrow or fat tissue, into a painful joint. The aim is to reduce inflammation, ease pain and support the joint's natural repair processes. It is most often used for early to moderate arthritis. It is not a cure, and research on how well it works is still developing.
How Stem Cell Therapy Works
Stem cells are cells that can develop into other cell types and release signalling proteins that influence inflammation and healing. In joint treatments, the cells most often used are mesenchymal stromal cells (commonly called mesenchymal stem cells). Current research suggests that much of their benefit may come from the signals they release rather than from turning into new cartilage. Whether they can rebuild cartilage in people has not been proven.
Where the Cells Come From
Bone marrow
A small amount of marrow is drawn, usually from the back of the hip bone under local anesthetic, and then processed to concentrate the cells.
Fat (adipose) tissue
A small amount of fat is collected, often from the abdomen or thigh, and processed to isolate the cells and supporting tissue.
Both are usually taken from your own body, which lowers the risk of rejection. Cells from other sources, such as donor or lab-expanded cells, are regulated differently and are not available everywhere, so ask your doctor exactly what will be injected.
How the Stem Cell Procedure Is Done
Assessment: your doctor reviews your symptoms, scans and arthritis stage to confirm you are a suitable candidate.
Cell collection: bone marrow or fat is collected under local anesthetic, usually taking less than an hour.
Processing: the sample is processed in a centrifuge or special system to concentrate the cells.
Injection: the concentrate is injected into the joint, often with ultrasound or X-ray guidance for accuracy.
Recovery and follow-up: most people go home the same day, followed by a gradual return to activity and a review of progress.
Who May Benefit from Stem Cell Therapy
May be a good fit
Early to moderate knee osteoarthritis
Pain that has not improved enough with PRP, physiotherapy or medication
People who want to delay or avoid surgery where appropriate
May not be suitable
Severe, bone-on-bone arthritis
Active infection or certain blood and bone marrow disorders
Current cancer or a recent cancer history, unless cleared by a specialist
What to Expect After Stem Cell Therapy
Soreness or swelling at the injection and collection sites is common for a few days. Rare risks include infection, bleeding and temporary pain flare-ups. Improvement is gradual over weeks to months, and results differ between people. Because the field is still evolving, choose a hospital that explains the evidence honestly and how its cells are prepared.
The right choice mainly depends on how advanced your arthritis is, how long you have had symptoms, and what you want to achieve. PRP is often tried first for mild to moderate joint pain because it is simpler and costs less. Stem cell therapy may be considered when PRP has not helped enough, or when the arthritis is moderate. Neither works well when the cartilage is largely gone, and only a specialist can confirm which suits you after examining your joint and reviewing your scans.
Choosing by Situation
Which treatment may fit which situation
Your situation
Option usually considered
Why
Mild arthritis or early joint pain
PRP, alongside physiotherapy and weight management
Lower cost and a simpler procedure, with a reasonable chance of symptom relief
Moderate arthritis, daily pain
PRP or stem cell therapy
Both are options, and the choice depends on your scans, budget and previous treatments
PRP gave little or short-lived relief
Stem cell therapy may be discussed
It acts differently and is studied for longer-lasting effects, though this is not guaranteed
Tendon or ligament injury
PRP is more commonly used
It has a longer track record in soft tissue injuries
Severe, bone-on-bone arthritis
Neither is likely to help enough. Surgery is usually advised
Injections cannot replace missing cartilage. See knee replacement
Factors That Influence the Decision
Medical factors
Arthritis grade on X-ray or MRI
Age, weight and activity level
Previous injections or surgeries
Blood disorders, infection or cancer history
Personal factors
Budget and number of sessions you can afford
How much downtime you can take
Your goals, such as walking, sport or delaying surgery
Comfort with evidence that is still developing
Questions to Ask Your Doctor
What stage is my arthritis, and is my cartilage still worth treating with an injection?
What exactly will be injected, where do the cells or platelets come from, and how are they prepared?
What results are realistic for me, and how will we measure whether it has worked?
What is the full cost, including repeat sessions, scans and follow-up visits?
What is the backup plan if the injection does not help enough?
Both PRP and stem cell injections have shown pain and function benefits in studies of knee osteoarthritis, but the evidence is still rated low to moderate in certainty, and neither has been proven to rebuild cartilage. PRP has the larger research base, and several analyses find it improves symptoms compared with placebo or hyaluronic acid. Stem cell research is promising but less consistent. Many major guidelines remain cautious about both. Individual results vary widely.
What Guidelines Say
How major organizations have rated these injections for knee osteoarthritis
Source
Position on PRP
Position on stem cell injections
AAOS (US orthopedic surgeons), 2021
Limited recommendation
Not specifically recommended
OARSI and ACR (2019)
No recommendation for routine use
Not recommended as routine care
French-speaking expert consensus
Considered an effective symptomatic treatment for early to moderate knee osteoarthritis
Not covered
NICE (UK), 2019
No major safety concerns, but efficacy evidence is limited in quality, so use with proper consent and audit
Not covered
A recent review of guidelines and trials up to late 2025 found that most contemporary international guidelines do not recommend either PRP or "stem cell" injections for knee osteoarthritis, citing inconsistent results, though some allow PRP in selected cases. Guidelines are updated over time, so ask your doctor which ones apply to you.
What Research Suggests
PRP
Meta-analyses report better pain and function than placebo or hyaluronic acid
A course of one to three injections is commonly used
Three-injection courses may work better than a single injection
Preparation methods differ between clinics, which makes results harder to compare
Stem cell therapy
A pooled analysis found improvements in knee pain and function
Minor side effects such as pain or swelling were reported, with no severe events in that analysis
Certainty of that evidence was rated very low to low because of study design and variability
Findings on cartilage change are mixed across studies
PRP vs Stem Cells Head to Head
An umbrella review of 28 meta-analyses linked both treatments with better knee scores, while noting that earlier meta-analyses had disagreed. Direct comparisons are limited, and some analyses suggest PRP performs as well as stem cell injections over the short term. That is one reason many doctors start with PRP, but the choice is individual.
What Is Still Unknown
Open questions
How long benefits last beyond one to two years
Which patients respond best
The best cell dose, source and number of injections
Whether cartilage is truly regrown or symptoms simply improve
Why results differ
Different preparation methods and platelet or cell concentrations
Different stages of arthritis in each study
Placebo effects, which can be substantial in joint pain trials
Small studies with short follow-up
The practical takeaway: these injections may ease pain for some people with early to moderate arthritis, but they are not a substitute for surgery when a joint is badly worn. If you are not getting enough relief, see your options for knee replacement and the recovery timeline, or read more on stem cell therapy for knee osteoarthritis.
Both PRP and stem cell injections are generally considered low-risk when done by a trained doctor in a clean, well-run setting. The most common side effects are temporary pain, swelling and stiffness at the injection site. Serious complications such as infection are uncommon but possible. The bigger safety concern with stem cell therapy is quality control: how the cells are collected, processed and handled matters a great deal.
Common Side Effects
PRP
Pain or soreness after the injection
Swelling, warmth or a feeling of fullness in the joint
Temporary stiffness for a few days
Bruising where blood was drawn
Stem cell therapy
Pain or swelling in the injected joint
Soreness at the bone marrow or fat collection site
Bruising or bleeding at the collection site
Temporary stiffness for a few days
What the Safety Research Shows
Severe adverse events and infection rates in a large safety analysis of knee injections
Measure
PRP
Cell-based injections
Severe adverse events
0.3%
0.5%
Infection rate
0.3%
0.4%
These figures come from a meta-analysis by the ESSKA Orthobiologics Initiative that pooled adverse event data from 559 studies covering more than 76,000 patients with knee osteoarthritis. It found PRP had the lowest overall adverse event rate among the injection types compared. A separate meta-analysis of randomized trials found PRP caused more adverse events than placebo injections, but a safety profile comparable to corticosteroid and hyaluronic acid injections. For stem cells, one pooled analysis reported minor side effects such as knee pain or swelling in a wide range of patients, with no severe events.
The Real Risk: Unregulated or Poorly Handled Cell Products
The serious safety warnings in stem cell medicine mostly involve products that were unapproved, contaminated or poorly processed rather than the procedure itself. In a widely reported US case, a dozen people were hospitalized with bacterial infections after receiving contaminated stem cell products from unapproved sources, and many had been treated for joint problems. Health officials also note that risks remain even when your own cells are used, because cells that are processed or manipulated outside the body can become contaminated, and treatments may simply fail to work as expected.
Questions to Ask Before Any Stem Cell Treatment
Where do the cells come from? Ask whether they are your own cells or from a donor or outside supplier.
How are they processed? Ask whether this happens in a sterile, quality-controlled setting and how much the cells are manipulated.
What is the regulatory status? Ask whether the treatment is approved, offered under a registered clinical study, or used under a recognized protocol in your country.
Who performs it? Look for a qualified orthopedic or sports medicine specialist, not just a clinic offering a package.
Are the promises realistic? Be cautious of clinics that promise a cure, guaranteed cartilage regrowth or avoiding surgery for sure.
Who Should Be Extra Careful
Speak to your doctor first if you have
A bleeding disorder or you take blood thinners
A low platelet count or other blood condition
An active infection or skin infection near the joint
A current or past cancer diagnosis
Other situations that need caution
Pregnancy or breastfeeding
A weakened immune system
Recent steroid injection or anti-inflammatory use before PRP, which your doctor may ask you to pause
Previous joint infection or surgery in the same knee
When to contact a doctor urgently: fever or chills, increasing redness, heat or swelling in the joint, severe pain that is getting worse instead of settling, or discharge from an injection or collection site. These can be signs of infection and need prompt medical attention.
PRP is the lower-cost option. In India, a knee PRP injection is commonly listed at roughly ₹8,000 to ₹50,000 per injection, while stem cell therapy for the knee is typically listed in the range of about US$2,000 to US$8,000 per procedure. Prices vary widely by city, hospital, doctor and the preparation method used, so treat these as rough ranges and always ask for a written, itemized quote.
Typical Price Ranges
Indicative knee treatment costs in India (public listings, subject to change)
Treatment
Typical listed range
What affects it most
PRP injection (knee)
About ₹8,000 to ₹25,000 per session in some cities, and up to ₹50,000 per injection in others
City, clinic, doctor's experience, PRP preparation kit, imaging guidance and number of injections
Stem cell therapy (knee)
Roughly US$2,000 to US$8,000 per procedure, with many listings between about US$3,000 and US$6,000
Cell source (bone marrow or fat), lab processing, one or both knees, imaging guidance, tests and follow-up
Both ranges are very wide, and they come from medical tourism listings and clinic pages rather than a fixed national price list. Stem cell prices in India are often quoted as significantly below those in the US or UK, but the final figure depends on exactly what is included. Prices change, so confirm the current quote with the hospital.
What Drives the Price Difference
Why stem cell therapy costs more
Cells must be collected from bone marrow or fat
Processing needs specialized equipment and laboratory handling
The procedure takes longer and is more involved
Some clinics include scans, tests and follow-up in the package
Why PRP prices vary so much
Different preparation systems produce different platelet concentrations
Ultrasound guidance may or may not be included
Metro hospitals usually charge more than smaller clinics
Multi-injection packages may reduce the per-injection price
How Many Sessions Will You Pay For?
Total cost depends on the number of injections. A French-speaking expert consensus suggests a PRP treatment course may include one to three injections, so a quote far above that should come with a clear medical reason. For stem cell therapy, many protocols use a single procedure, but your doctor will advise based on your knee. Be cautious of long, pre-paid packages that are not tied to your examination and scans.
What to Check in a Quote
Consultation and tests: whether the doctor's visit, X-ray, MRI and blood tests are included or billed separately.
The procedure itself: cell or platelet collection, processing, injection and any imaging guidance.
One knee or both: some quotes cover a single knee and others both.
Follow-up and physiotherapy: review visits and rehabilitation, which can add to the total.
Travel costs for international patients: accommodation, local transport and the length of stay, if you are travelling to India for treatment.
Will Insurance Cover It?
Coverage is generally limited. PRP is described as costly and inconsistently reimbursed, and insurance cover for stem cell therapy for osteoarthritis is described as rare. Check with your insurer before treatment, and ask the hospital for a written estimate you can submit.
Price is not a quality guide: a very low quote may mean shortcuts in cell processing or no imaging guidance, while the highest price does not guarantee a better result. Compare what is included, who performs the procedure, and how the cells are prepared, not only the total.
Quick answers to the questions patients ask most often about stem cell therapy and PRP for knee pain and arthritis.
What is the main difference between stem cell therapy and PRP?
PRP (platelet-rich plasma) is a concentrate of platelets and growth factors from your own blood, used mainly to calm inflammation and pain. Stem cell therapy uses cells, usually taken from your bone marrow or fat tissue, which are being studied for their ability to support tissue repair. PRP is simpler and generally less expensive, while stem cell therapy is more involved and generally costlier.
Which is better for knee arthritis, stem cell therapy or PRP?
Neither is clearly better for everyone. PRP is often tried first for mild to moderate arthritis because it has a larger research base, lower cost and a simpler procedure. Stem cell therapy may be considered when arthritis is moderate or PRP has not given enough relief. Your doctor should decide after examining your knee and reviewing your scans.
Can PRP or stem cell therapy regrow knee cartilage?
Not proven. Both treatments may reduce pain and improve function in some people, but studies on cartilage change are inconsistent, and neither treatment is established to regrow lost cartilage. Be cautious of clinics that promise guaranteed cartilage regrowth.
How long do the results of PRP and stem cell therapy last?
It varies from person to person. PRP relief often lasts from several months to around a year. Some stem cell studies report longer relief, but long-term data is limited and results are not guaranteed. Improvement usually builds gradually over weeks rather than appearing straight away.
How many PRP injections do I need?
A PRP course for knee osteoarthritis commonly includes one to three injections, based on a French-speaking expert consensus. Your doctor will decide the number based on your knee and your response. Be cautious of long pre-paid packages that are not based on your examination and scans.
Are stem cell therapy and PRP safe? What are the side effects?
Both are generally considered low-risk when done by a trained doctor in a clean, well-run setting. Common side effects are temporary pain, swelling and stiffness at the injection site, plus soreness where blood, bone marrow or fat was collected. Infection is uncommon but possible. With stem cells, how the cells are handled and processed matters, so ask where they come from and how they are prepared. See risks and side effects above.
How much does stem cell therapy or PRP cost in India?
Public listings commonly show a knee PRP injection at roughly ₹8,000 to ₹50,000 per injection, and stem cell therapy for the knee at roughly US$2,000 to US$8,000 per procedure. Prices vary widely by city, hospital, doctor and what the package includes, so ask for an itemized written quote. See cost in India above.
Can I have stem cell therapy if PRP did not work?
Possibly. If PRP gave little or short-lived relief and your arthritis is still early to moderate, your doctor may discuss stem cell therapy as the next step. It works differently from PRP, but it is not guaranteed to help. If the cartilage is largely gone, neither injection is likely to help enough.
Do these treatments work for severe, bone-on-bone arthritis?
Unlikely. Injections cannot replace cartilage that is already gone, and surgery is usually advised for severe damage. In that case, knee replacement is the proven option, and a partial replacement may suit you if only part of the knee is worn.
Who should avoid PRP or stem cell therapy?
Speak to your doctor first if you have a bleeding disorder, a low platelet count, take blood thinners, have an active infection, have a weakened immune system, or have a current or past cancer diagnosis. Pregnancy and breastfeeding also need medical advice. Your doctor will tell you whether either treatment is suitable.
What is the recovery time after a PRP or stem cell injection?
Recovery is short compared with surgery. Most people go home the same day and return to light activity within a few days, although soreness at the injection or collection site can last a little longer. Your doctor will advise when to resume exercise. For comparison, surgery needs months, as shown in the knee replacement recovery timeline.
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