Frequently Asked Questions About Stem Cell Therapy

Evidence reviewed through: July 2026

This FAQ covers stem cell therapy through Sterling Longevity's partner clinics in Bangkok — what is known, what is not, and what to ask before deciding.

How we answer questions here. Where the evidence is good, we say so and cite it. Where it is

uncertain, we say that plainly rather than rounding it into confidence. Some answers below are

shorter and less satisfying than you may expect, and that is deliberate: a specific percentage in a

bulleted list looks authoritative, but with no denominator, no population and no follow-up period

behind it, it is not a statistic. We give numbers where a study measured them, and say so where

none has.

General Questions

What is stem cell therapy?

Stem cell therapy uses mesenchymal stromal cells (MSCs) with the aim of reducing inflammation and supporting tissue repair. The mechanism is understood to be primarily paracrine and immunomodulatory — the cells secrete bioactive molecules and regulate the local immune response, rather than replacing damaged tissue by turning into it (Caplan and Correa, 2011).

That distinction matters. Marketing often describes stem cells "rebuilding" or "regrowing" tissue. The better-supported description is that they change the biological environment around an injury.

Sterling Longevity partners with Sterling-Certified clinics that meet our quality standards — from cell sourcing to post-treatment follow-up.

What conditions is it used for, and how strong is the evidence for each?

This is the question that most deserves an honest answer, because evidence maturity varies enormously between conditions. MSC therapy is investigational for essentially all of the conditions below — it is not an approved treatment for them in most countries.

A broader caution worth knowing: across the field, most clinical-stage MSC therapies have not met their primary efficacy endpoints, and MSC effects in humans have proven "not as robust as demonstrated in preclinical studies" (Levy et al., 2020).

Not sure about your situation? Take our 5-minute assessment or schedule a free Discovery Call.

How do I know if I'm a candidate?

Candidacy is a clinical judgement, but people generally considered include those with:

• Chronic conditions that have not responded to conventional treatment
• Realistic expectations about what is and isn't established
• A reasonable overall health baseline
• No active cancer or uncontrolled infection

Age is not in itself a limiting factor.

Complete candidate criteria →

What distinguishes Sterling-Certified clinics?

These are operational commitments, not research findings. We do not publish comparison figures for other providers' release specifications, because we have no verified data on them.

Safety & Risks

Is stem cell therapy safe?

The honest answer is: safe enough that serious complications were uncommon in clinical trials, with one consistently documented side effect — and with real caveats about what trials can and cannot tell you.

What the largest safety reviews of intravenous MSC therapy found:

• Fever is the one adverse event consistently and significantly linked to MSC infusion. In a review of 36 studies (1,012 participants), the odds ratio for fever was 16.82 (95% CI 5.33–53.10) (Lalu et al., 2012). An updated review of 55 randomised trials (2,696 patients) found a relative risk of 2.48 (95% CI 1.27–4.86) (Thompson et al., 2020). A 2026 review confined to umbilical cord MSCs — 42 trials, 2,280 patients — found a relative risk of 2.34 (95% CI 1.02–5.35) (Hum et al., 2026).
• Those same reviews found no statistical association between MSC therapy and infection, blood clots, organ complications, death or malignancy.
• No trial in these reviews was stopped early for safety reasons.

Two things that limit how far this reassures:

1. Follow-up is short. In the foundational review, follow-up ranged from 0.5 to 60 months, and the authors noted that roughly half of studies did not report how long they followed patients for adverse events at all (Lalu et al., 2012).
2. Trials are not the commercial marketplace. A public health investigation identified 20 patients with bacterial infections after receiving umbilical cord blood–derived products marketed as stem cell treatment for pain and arthritis; all but one required hospitalisation, and 65% of unopened vials tested were contaminated (Hartnett et al., 2021).

On serious-adverse-event percentages. Figures such as "serious adverse events: <1%" and "infection at the injection site: <0.1%" are quoted routinely in this field, and we could not trace either to any source. Neither major safety review reports a serious-adverse-event rate — both report effect estimates versus control, which cannot be converted into a bare percentage. See our Safety Profile for the full evidence.

Can stem cells cause cancer?

No MSC-derived tumours have been documented in the published clinical literature — but the question is not fully closed, and we should not pretend otherwise.

What supports low risk:

• An autopsy study of 18 patients who had received donor MSCs found no ectopic tissue formation and no tumours of donor origin (von Bahr et al., 2012).
• A 10-year follow-up of 72 patients treated with bone marrow MSCs or chondrocyte implantation for knee cartilage defects found no deep infection and no tumour in either group (Teo et al., 2019).
• Large meta-analyses found no association with malignancy (Thompson et al., 2020; Hum et al., 2026).
• MSCs are not pluripotent and have limited proliferative capacity, unlike embryonic stem cells.

What remains open:

• The autopsy series is 18 patients; the 10-year cohort is 72. These are meaningful, not definitive.
• The authors of the foundational safety review explicitly noted that because MSC use "may be associated with neoplastic growth long term," it was difficult to understand why half of studies failed to report adverse-event follow-up duration (Lalu et al., 2012).
• Tumour latency can exceed the follow-up period of most trials.

The accurate position: no cases have been documented, the biological rationale for low risk is sound, and the follow-up is not yet long enough to exclude rare or late events. That is a different statement from "stem cells cannot cause cancer," and the difference is worth holding onto.

(One claim to watch for: MSC secretions are sometimes described as having "anti-tumour properties." Laboratory work does document anti-tumour factors in MSC-conditioned medium under particular culture conditions (Madrigal et al., 2014) — but that is secretome research in a dish, not evidence that the therapy protects against cancer in patients.)

Will my body reject the cells?

Rejection in the organ-transplant sense is not the concern here — but the older claim that MSCs are "immunoprivileged" is out of date.

The current position, from a review titled precisely "Mesenchymal stem cells: immune evasive, not immune privileged": MSCs were long described as immune privileged, "however, recent studies describing generation of antibodies against and immune rejection of allogeneic donor MSCs suggest that MSCs may not actually be immune privileged." Whether this affects treatment outcomes is not known (Ankrum, Ong and Karp, 2014). A later review, "Immunoprivileged no more," reports both cell-mediated and antibody responses to MHC-mismatched MSCs, with clinical implications still unknown (Berglund et al., 2017).

What this means practically:

• Immune responses to donor cells are documented, not theoretical.
• Their clinical importance is genuinely uncertain — not a known danger, but no longer a settled non-issue.
• It is most relevant to repeated donor-cell dosing, where sensitisation is the theoretical concern.
• In one randomised trial of intravenous allogeneic umbilical cord MSCs, no patients developed antibodies to the cells — but only 7 patients were tested (Bartolucci et al., 2017).

In practice, allogeneic MSCs are given without HLA matching. What has changed is the justification for that: it rests on MSCs being immune evasive, with antibody responses documented, rather than on an immune privilege the evidence no longer supports. Nor does it make donor cells preferable to your own — see the cell-source question below.

What are the side effects?

Consistently documented:

• Fever — the one adverse event significantly associated with MSC infusion across all three major reviews (above). Typically mild and resolving within 24–48 hours. It is the treatment's most reproducible side effect rather than a sign that the treatment is working, and you should know how to distinguish it from infection.

Commonly reported in trials:

• Fatigue and headache
• Acute infusion-related reactions (8% of participants in uncontrolled trials in the foundational review)
• For injections into a joint specifically: injection-site pain (RR 2.04) and joint swelling (RR 3.39) relative to control (Awad et al., 2026)

Reported but not statistically associated with MSC treatment:

• Infection, blood clots, organ complications, death, malignancy

Documented outside the trial setting:

• Serious bacterial infection from contaminated product (Hartnett et al., 2021)

We have not assigned a percentage to each item, because the trials report events in specific populations over specific windows, and reproducing those as universal rates would misrepresent what was measured.

You are monitored throughout treatment with 24/7 medical support during your stay.

Are there any long-term risks?

Long-term data is limited, and an absence of identified effects is not the same as evidence of absence.

What is actually established:

• MSCs do not permanently integrate into your tissue. An autopsy study found donor DNA at low levels declining with time since infusion, supporting a "hit and run" mechanism, and concluded "the lack of sustained engraftment limits the long-term risks" (von Bahr et al., 2012).
• MSCs do not alter your DNA.
• The longest good-quality human follow-up we could identify is 10 years, in 72 patients treated for knee cartilage defects with autologous bone marrow cells, with no tumours or deep infections (Teo et al., 2019).
• A separate 5-year study of 11 patients given autologous adipose MSCs into the knee reported no treatment-related adverse events across the full 5 years (Kim et al., 2022).

What is not established:

• There is no systematic long-term surveillance of MSC recipients. Most trial follow-up is under five years, and roughly half of the studies in the foundational safety review did not report follow-up duration for adverse events (Lalu et al., 2012).
• The 10-year data above is autologous bone marrow cells implanted surgically for cartilage defects. It does not automatically transfer to intravenous allogeneic umbilical cord cells.

MSCs have been in clinical use since the mid-1990s, and no long-term harms have been established in that time. It is worth being precise about what that does and does not mean. Nobody has systematically followed a large cohort for twenty years, so the absence of identified harm reflects the absence of surveillance as much as it reflects the absence of risk. The honest version is: no long-term harms have been identified, and the follow-up needed to confidently rule them out has not been done.

Does the type of cell or the route matter?

Yes — considerably, and this is often glossed over.

• Cell source. Meta-analysis has shown bone marrow MSC infusion to be safe, but specialists have explicitly cautioned that "it is not clear if this also applies to diverse new cell products derived from other sources, such as adipose and perinatal tissues." Different products carry varying levels of procoagulant tissue factor and may trigger an instant blood-mediated inflammatory reaction (Moll et al., 2019). Umbilical cord is a perinatal source.
• Culture expansion. Internationally, stem cell products that are substantially manipulated — which includes cells expanded in culture over weeks — are classified as drugs or advanced therapy medicinal products, a standard aligned with the US FDA, the EMA and Australia's TGA (Lovell-Badge et al., 2021).
• Route. Safety evidence from intravenous studies does not automatically describe joint injection, and vice versa. The most severe documented harms in the literature have been route-specific.

Who should not have this treatment?

Conditions that make treatment inappropriate or require specialist evaluation include:

• Active cancer or recent cancer history — the most important one. Safety in active malignancy is not established.
• Active infection requiring treatment
• Significant bleeding disorders or anticoagulation
• Unstable cardiovascular disease
• Pregnancy
• Poorly controlled diabetes, significant immunosuppression, or recent major surgery — each requires individual assessment

We do not publish specific numeric thresholds. Whether a particular laboratory value or medication dose precludes treatment is a clinical judgement about an individual, not something a web page should decide.

The medical team reviews every case individually.

Treatment Process

What type of stem cells are used?

Sterling-Certified clinics use mesenchymal stromal cells from umbilical cord tissue (Wharton's jelly), from donated cords after healthy births.

Honest reasons this source is used:

• Practical availability — no harvest procedure for the patient, unlike bone marrow aspiration or liposuction, each of which carries its own risks
• Consistency — cells come from a screened, characterised donor source rather than varying with the patient's own age and health
• Yield — cord tissue provides abundant cell numbers

What we should not claim: that donor cord cells are proven superior to your own cells. A review of the field states plainly that "no definitive clinical advantage of autologous MSCs over allogeneic MSCs has been demonstrated to date" (Ankrum, Ong and Karp, 2014) — a statement that cuts against superiority claims in either direction.

Also note the counterweight above: safety data from bone marrow products may not transfer to perinatal sources (Moll et al., 2019).

What is not used: embryonic stem cells, or animal-derived cells.

How many cells will I receive?

These are programme specifications — business facts, verified per batch by flow cytometry.

On "more cells is better": that is a marketing claim rather than an evidence-based one. What the dose literature suggests is a window rather than a ladder — though it is genuinely contested:

• An analysis of 914 MSC trials found minimum effective intravenous doses clustering around 100–150 million cells, "with lower and higher doses being less effective" (Kabat et al., 2020).
• In knee osteoarthritis, a network meta-analysis of 11 randomised trials found moderate cell doses outperformed high doses long-term, with high doses producing more adverse events (Xie et al., 2026).
• Arguing the other way, a 2-year study of 18 patients receiving low, medium or high-dose adipose MSCs into the knee found improvement at all doses, but statistical significance "mainly in the high-dose group," with low- and medium-dose outcomes tending to deteriorate after 1 year while high-dose plateaued to 2 years. The authors nonetheless flagged "potential concerns about the durability" of outcomes (Jo et al., 2017). This was a Level-3 cohort study of 18 people, not a randomised trial.

The fair summary is that dose probably matters, the optimum is unresolved, and "more is better" is not established — particularly since the higher-tier randomised evidence points toward a moderate window.

Are the cells fresh or frozen?

Fresh — prepared on the day of treatment. The scientific case for fresh over frozen is genuinely contested, though, and worth setting out properly.

The argument for fresh: freeze-thawed MSCs show reduced responsiveness to inflammatory signals, impaired production of anti-inflammatory mediators, increased triggering of the instant blood-mediated inflammatory reaction, and stronger complement activation immediately after thawing (Moll et al., 2014). That is a real, mechanistically documented effect.

The argument against it mattering clinically: a systematic review of 18 comparative preclinical studies — 257 in-vivo efficacy experiments across 101 outcome measures — found only 2.3% of comparisons significantly different, and of those six, two favoured fresh and four favoured cryopreserved cells. The authors concluded that most efficacy and potency outcomes were not significantly different, and that the evidence supports considering cryopreserved products (Dave et al., 2022). This is animal-model evidence, not human trial evidence.

The honest summary: freshly prepared cells avoid a documented post-thaw impairment, which is a defensible reason to prepare them fresh. Whether that translates into better patient outcomes has not been demonstrated, and any table presenting frozen cells as straightforwardly "degraded" is asserting more than the evidence carries.

How long does treatment take?

All new guests begin with the Discovery programme. After Day 2 bloodwork and physician consultation, you decide together whether to proceed. Your Discovery investment applies almost entirely as credit toward an upgrade.

What's the Day 1 protocol?

Assessment (morning): comprehensive blood panel, vital signs, physical evaluation.

Preparation therapies (afternoon): exosome therapy, NAD+ IV, anti-inflammatory preparation.

Drawing blood first establishes your baseline before any therapy is given, which is sound practice. We should be straightforward, though, that the specific preparation protocol is a clinical-practice choice rather than an evidence-based standard — we are not aware of controlled trials showing that exosome or NAD+ pre-treatment improves stem cell outcomes.

Do I need multiple treatments?

Programmes are designed around a single treatment course. Whether repeat treatment helps is not well established, and the evidence points in more than one direction: in knee osteoarthritis, a network meta-analysis of 16 trials found repeated MSC injections produced greater improvement at 6 and 12 months than single injections — but also a higher incidence of adverse events (Deng et al., 2025).

If repeat allogeneic dosing is considered, the sensitisation question above is worth raising with your clinician.

There is no pressure for follow-ups.

Who performs the treatment?

Board-certified physicians with training in regenerative medicine, in a JCI-accredited hospital setting, with continuous vital monitoring, emergency protocols, and 24/7 medical support during your stay.

Results & Expectations

What results can I expect?

We cannot give you a reliable percentage, and you should be wary of anyone who can.

Outcome tables of the kind commonly published in this field — "50–70% pain reduction in 70–80% of patients," with similar figures for function, inflammation, quality of life and medication use — are clinic-reported observations presented in the form of research data. A clinic's own uncontrolled observations are not evidence of efficacy, however carefully they are recorded, because there is no comparison group to show what would have happened anyway.

What the controlled literature supports, honestly:

• Many people do report meaningful symptom improvement, and trials consistently show improvement from baseline.
• A large share of that improvement is attributable to context rather than to the cells. A 2025 meta-analysis of placebo-controlled trials calculated that contextual (placebo-related) effects accounted for roughly 63% of pain reduction and 61% of functional improvement at 6 months, and about 50% of pain relief at 12 months, concluding that MSCs themselves confer "only a modest incremental benefit" (Yin et al., 2025).
• Structural repair is not established. A 2026 meta-analysis of 28 randomised trials in knee osteoarthritis found no consistent structural benefit on MRI, concluding the role is "primarily symptom-modifying rather than structure-modifying" (Awad et al., 2026).

That placebo finding is not a reason to dismiss what patients feel — contextual benefit is real benefit, and people genuinely improve. It is a reason to be sceptical of any provider quoting you a precise success rate.

How soon might I notice changes?

Trials typically assess outcomes at 3, 6 and 12 months, and improvement in those trials is gradual rather than immediate. Individual timelines vary widely, and a week-by-week schedule of expected changes would imply a predictability the trials do not show.

How long do results last?

Benefit is consistently demonstrated to about 12 months. Beyond that the data thins sharply.

• Formal European consensus on cell therapy for knee osteoarthritis describes clinical benefit up to 12 months (de Girolamo et al., 2025).
• The longest placebo-controlled trial we could identify followed patients to 60 months: scores improved significantly at 6, 12, 24 and 36 months, then "declined steadily after 36 months, with scores nearing baseline at 60 months." That trial had 29 completers, with blinding maintained only to 12 months (Jafar et al., 2026).
• An uncontrolled 5-year study of 11 patients given a single high-dose adipose MSC knee injection reported pain and function significantly improved from 6 months through to 5 years, with structural scores improved to 3 years — though chondral defect size on MRI did not change significantly (Kim et al., 2022).

Those two results appear to conflict, and the difference is instructive. The uncontrolled series shows benefit maintained at five years; the placebo-controlled trial shows benefit fading to baseline by five years. Since roughly half to two-thirds of the symptomatic improvement after MSC injection is attributable to context rather than the cells (Yin et al., 2025), a study with no comparison group would be expected to show sustained improvement whether or not the cells were doing the work. That is precisely why controlled trials matter for durability claims.

Multi-year durability figures — "typically 2–5 years or longer," often with condition-specific averages — are quoted routinely in this field. We could not find a source for any of them. If a provider quotes you multi-year durability, ask which trial measured it — and whether that trial had a control group.

What if it doesn't work for me?

No treatment works for everyone, and for the conditions treated here the honest position is that response cannot be reliably predicted. Quoted success rates — "60–80% depending on condition" and similar — have no traceable source, and no validated way of predicting who will respond currently exists.

What we commit to: candidacy screening, discussing probabilities rather than promises, tracking your progress after treatment, and exploring alternatives if results are not what you hoped.

Will I still need surgery?

Possibly. Stem cell therapy is not established to prevent joint replacement.

No controlled trial has shown that cell therapy reduces the rate of joint replacement surgery. Figures for surgeries "cancelled" or "delayed" after treatment come from uncontrolled clinic observation, with no comparison against a group that did not receive the treatment, so they cannot tell you what the treatment changed.

What the evidence does show: stem cell therapy does not regrow cartilage in significantly damaged joints. It supports symptom improvement, not structural restoration (Awad et al., 2026). For advanced structural damage, surgery may still be the appropriate option, and a formal cost-effectiveness analysis of delaying knee replacement found that biologic injection was not cost-effective, driven by "a lack of established clinical efficacy" (Rajan et al., 2020).

Can I combine stem cells with other treatments?

Physical therapy, rehabilitation and lifestyle modification are compatible and are supported by stronger evidence than cell therapy itself for most joint conditions.

On anti-inflammatory medication — this deserves care:

The recommendation to avoid NSAIDs around cell therapy has some evidential basis, but it is animal evidence with an important asymmetry. In a rat model of post-traumatic osteoarthritis, NSAIDs given before MSC injection had minimal effect on benefit, whereas NSAIDs given after injection substantially reduced therapeutic efficacy. The authors' stated clinical relevance: the data "support the clinical recommendation of avoiding NSAID use after hMSC injection but suggest that using NSAIDs before treatment may not substantially diminish" efficacy (Sok et al., 2022). They also noted that clinical use of cell therapies "has accelerated in recent years without sufficient scientific evidence defining best-use practices."

⚠️ Do not stop prescribed medication on the basis of this page. Some people take daily aspirin or other anti-inflammatories for cardiovascular or other medical reasons where stopping carries real risk. Any change must be decided with the clinician who prescribed it.

Specific guidance for your situation is provided by the medical team.

Cost & Insurance

How much does it cost?

Sterling Longevity offers several programme tiers. All are all-inclusive — accommodation, airport transfers, medical consultations, lab work, and 12-month follow-up.

All new guests start with the Discovery programme, the only commitment required before arrival, and it applies almost entirely as credit toward any treatment programme chosen on-site.

Programme pricing is shared during your Discovery Call.

Schedule your free Discovery Call →

What's included?

Included: the treatment itself, all medical consultations and assessments, Day 1 protocol, 5-star hotel accommodation in Bangkok, private airport transfers, daily breakfast, medical coordinator support, 12-month follow-up, and all hospital and lab fees.

Not included: international flights, travel insurance (required), personal meals beyond breakfast, and personal expenses.

No surprise bills.

Do you offer financing?

Yes — medical financing through partnered lenders, payment plans, credit card acceptance, and HSA/FSA compatibility. Contact us to discuss options.

Does insurance cover it?

Generally, no. Most insurers classify stem cell therapy as experimental — which, for the conditions treated here, reflects the state of the evidence rather than an arbitrary judgement.

Options that sometimes help: HSA/FSA funds, some international health plans, documentation for reimbursement attempts, and medical tourism insurance.

Travel to Thailand

Is Thailand safe for medical treatment?

Thailand is one of the world's established medical tourism destinations, with a large number of JCI-accredited hospitals, decades of international patient experience, English-speaking medical professionals, and costs below those in the US and Europe.

A genuine consideration when travelling for treatment: the regulatory protections of your home country do not apply. Treatments provided here are not FDA-approved in the United States. Travelling for care is lawful and common; it is also a real trade-off worth weighing deliberately.

Do I need a visa?

Most Western travellers: no visa required for short stays.

Requirements: passport valid 6+ months beyond arrival, return ticket, proof of accommodation, travel insurance (we require this).

Visa rules change — confirm current requirements before booking. Visa-on-arrival or e-visa options exist for longer programmes.

How long should I plan to stay?

Can my partner come?

Yes. Companion accommodation is included in all programmes, with airport transfers and daily breakfast at the same hotel.

Do I need to speak Thai?

No. The medical team and support staff speak fluent English, with international patient coordinators and translation services available.

Recovery

What's recovery like?

Most people experience mild fatigue initially, with gradual change over weeks to months. Fever within the first 24–48 hours is the most commonly documented reaction (above).

Your clinical team will give you a recovery plan for your situation. We do not publish fixed week-by-week activity, return-to-work or lifting-limit tables: those are individual clinical recommendations that depend on your condition, procedure and baseline, and presenting them as universal timelines would be misleading.

What should I watch for?

Contact the medical team promptly if you experience:

• Fever above 38.3°C (101°F) persisting beyond 48 hours, or any fever with worsening symptoms
• Difficulty breathing, swelling of the face, lips or tongue, or widespread rash
• Severe or increasing pain, swelling, redness spreading, or discharge at an injection site
• Any symptom that concerns you

Because infection from contaminated product is a documented risk in this field (Hartnett et al., 2021), symptoms suggesting infection should be taken seriously and assessed promptly rather than assumed to be a normal healing response.

24/7 support is available during your stay.

What should I eat afterwards?

General anti-inflammatory eating patterns — oily fish, vegetables, fruit, nuts, olive oil, adequate protein, limited processed food and alcohol, good hydration — are sensible for general health. We are not aware of controlled evidence that any particular diet improves stem cell treatment outcomes, so this is general health advice rather than a treatment protocol.

How will I know if it's working?

Useful things to track: pain level and frequency, mobility and daily function, energy, sleep, and any change in medication needs. Trials typically assess at 3, 6 and 12 months.

Sterling Longevity provides post-treatment tracking tools and quarterly check-ins.

Still Have Questions?

📧 Email: hello@sterlinglongevity.com

💬 WhatsApp: Available on request

🌐 Website: www.sterlinglongevity.com

📅 Book Discovery Call

No obligation. No pressure. Just answers — including the ones where the answer is "we don't know yet."

Related Resources

• Safety Profile — the full safety evidence in detail
• Stem Cells vs PRP — how the two compare on evidence
• Who Is a Candidate?
• What's Included
• 12 Questions to Ask Any Clinic