Scope of This Review
This page reviews the published evidence on frailty as a clinical syndrome, on what is established for treating it, and on where cell therapy currently stands. Frailty has a well-defined clinical literature of its own — the Fried phenotype, the frailty index, sarcopenia — and this page uses those constructs as their authors defined them rather than as loose synonyms for ageing.
Frailty is also one of the few indications in regenerative medicine where randomised, placebo-controlled trials have reported significant benefit. Those results are reported here at full strength, with their effect sizes and confidence intervals, alongside what remains unsettled.
What Frailty Actually Is
Frailty is a clinically recognisable state of increased vulnerability arising from age-associated decline in reserve and function across multiple physiological systems [1]. The practical consequence is disproportion: a minor illness, a new medication or a fall produces a much larger loss of function than the same event would in a robust person of the same age, and recovery is slower and often incomplete [7].
It is distinct from both normal ageing and simple deconditioning. Two people of the same age can have very different physiological reserves, and frailty describes the low-reserve state rather than the number of years.
The Fried phenotype
Fried and colleagues established the most widely used operational definition in 2001, based on five measurable criteria [2]:
Classification: none of the five is robust; one or two is pre-frail; three or more is frail [2].
A second major approach, the frailty index, counts accumulated health deficits rather than applying a phenotype. The two identify overlapping but not identical groups, which is one reason prevalence estimates vary.
How common is it?
A systematic review pooling 21 studies and 61,500 community-dwelling adults aged 65 and over found an overall weighted prevalence of 10.7% (95% CI 10.5–10.9) — 9.9% (9.6–10.2) using a purely physical definition and 13.6% (13.2–14.0) using a broader phenotype that includes psychosocial factors. Individual study estimates ranged widely, from 4.0% to 59.1%, largely because of how frailty was defined [3].
Is it reversible?
Partly, and this is the most useful thing to know. Pre-frailty in particular can improve with intervention, and even established frailty has been shown to respond — the Fiatarone trial below enrolled participants who were already frail and severely deconditioned [4]. What no study has established is that frailty can be prevented in the sense of being avoided altogether.
The Biology: Why Reserve Declines
Several ageing processes converge on the frailty phenotype.
Stem cell exhaustion is one of the recognised hallmarks of ageing: the number and regenerative function of tissue-resident stem and progenitor cells decline with age, reducing the capacity to repair tissue after injury [8].
Inflammaging describes the chronic, low-grade, sterile inflammation that develops with age. Circulating inflammatory mediators including TNF-α, IL-6 and CRP rise, and this state is associated with the transition from robustness toward frailty [9][10].
These interact. Chronic inflammation damages tissue; damaged tissue requires repair; a depleted regenerative capacity responds inadequately; further functional loss follows. That loop is the mechanistic rationale for testing cell-based therapy in frailty — and a rationale is a reason to run trials, not a result.
How MSCs are thought to act. Mesenchymal stromal cells are understood to work mainly through immunomodulation and paracrine signalling — secreting factors that damp inflammatory responses and support endogenous repair — rather than by engrafting and replacing tissue.
What the Trials Show
Randomised, placebo-controlled evidence
Umbilical cord MSCs. A Phase I/II randomised, double-blind, placebo-controlled trial gave intravenous human umbilical cord-derived MSCs or placebo to adults diagnosed with aging frailty, with six months of follow-up. The primary endpoint, the physical component score of the SF-36, improved from the first post-treatment visit and was sustained throughout, with greater change than placebo (p = 0.042). EQ-VAS quality-of-life scores improved significantly from two months (p = 0.023) and continued to six months (p = 0.002) against placebo. The Timed Up and Go test showed a significant group difference with continued improvement over six months, and pro-inflammatory cytokines fell. The authors concluded that intravenous umbilical cord MSC infusion was safe and effective in aging frailty [5].
This is the only randomised trial to date using umbilical cord-derived cells for this indication.
The largest trial. A randomised dose-finding trial in 148 ambulatory adults with frailty tested allogeneic bone-marrow-derived MSCs against placebo. The primary endpoint, six-minute walk distance, improved by 63.4 metres (95% CI 17.1–109.6; p = 0.0077) at month 9. At month 6 the difference was 41.3 metres (95% CI −2.4–84.9; p = 0.0635) — favourable but not statistically significant. The authors describe the effect as clinically meaningful and both dose- and time-dependent, and identified soluble TIE2 as a candidate biomarker of response [6].
The month-6 result matters as much as the month-9 one: the benefit took time to appear, and a trial stopping at six months would have reported a null.
The CRATUS programme
Two earlier studies from the University of Miami established the safety base for this work.
The Phase 1 study was a non-randomised, open-label dose-escalation study — not a placebo-controlled trial. Fifteen patients received a single intravenous infusion of allogeneic bone-marrow MSCs at 20 million (n=5), 100 million (n=5) or 200 million cells (n=5). There were no treatment-emergent serious adverse events at one month and no significant donor-specific immune reactions over six months; one death occurred at 258 days after infusion in the 200-million group. Across the treatment groups, six-minute walk distance improved at three months (p = .02) and six months (p = .001), and TNF-α fell at six months. Because there was no placebo arm, these are within-group changes [11].
The Phase 2 trial was randomised, double-blind and placebo-controlled, comparing 100 million versus 200 million cells versus placebo in 30 patients of mean age 75.5 ± 7.3. No therapy-related serious adverse events occurred at one month. Six-minute walk test, short physical performance battery and forced expiratory volume improved in the 100-million group (p = .01) — and not in the 200-million or placebo groups. Serum TNF-α decreased in the 100-million group (p = .03), and B-cell intracellular TNF-α improved in both cell groups [12].
On dose, the evidence disagrees with itself
This is worth stating plainly rather than resolving artificially.
The Phase 2 CRATUS trial found the lower of its two doses performed better — 100 million outperformed 200 million on every physical endpoint [12]. The much larger 2026 trial reports dose- and time-dependent increases in its primary endpoint [6].
Those point in different directions, in trials of different sizes using different products. Optimal dose in frailty is unresolved. Conclusions drawn about dose in other indications, such as joint injection, do not transfer here: the route is systemic rather than local, and the biology being targeted is different.
What has not been shown
- Durability beyond six to nine months has not been established in any controlled trial
- No trial has tested hard outcomes — disability, hospitalisation, institutionalisation, survival. Every result above is a physical performance measure, a patient-reported score or a biomarker
- No trial has identified who responds. Whether pre-frail people respond differently from frail people has not been tested; the trials above enrolled participants who already met frailty criteria
- Nothing here concerns lifespan. These are studies of function in people who are already frail, not studies of ageing itself
What Has the Strongest Evidence: Exercise
The most striking result in the frailty literature is not a cell therapy trial.
A randomised, placebo-controlled trial enrolled 100 frail nursing-home residents with a mean age of 87.1 years (range 72–98) into four arms: progressive resistance exercise training, multinutrient supplementation, both, or neither, over ten weeks. Muscle strength increased by 113 ± 8% in those who trained, compared with 3 ± 9% in those who did not. The authors concluded that high-intensity resistance training is a feasible and effective means of counteracting muscle weakness and physical frailty in very elderly people [4].
The same trial found that multinutrient supplementation without concomitant exercise did not reduce muscle weakness or physical frailty [4]. Nutrition supports training; it does not substitute for it.
Any honest account of frailty puts supervised progressive resistance training first. It has the largest effect size, the longest track record, and it is available to almost everyone.
Comparing the Approaches
These are not mutually exclusive, and the trial evidence does not position cell therapy as an alternative to exercise. In the studies above, participants were not asked to stop exercising.
Safety
Across the frailty trials, the safety record is reasonable and is worth stating positively.
- No therapy-related serious adverse events at one month in either CRATUS study [11][12]
- No significant donor-specific immune reactions over six months in the Phase 1 study [11]
- The randomised umbilical cord trial monitored all serious and non-serious adverse events over six months and reported the approach as safe [5]
Two qualifications belong with that. The Phase 1 study recorded one death at 258 days after infusion in its highest-dose group [11]— outside the one-month safety endpoint, in a study with no comparison arm, so it cannot be attributed either way. And these are small studies: 15, 30 and 148 participants. They can exclude common harms, not rare ones.
Who These Trials Studied
The published trials enrolled ambulatory older adults meeting frailty criteria — mean ages in the mid-seventies in the CRATUS studies, and community-dwelling participants in the larger 2026 trial. Participants were medically stable enough for outpatient infusion.
Beyond that, the evidence does not support statements about who benefits most. No trial has compared pre-frail with frail participants, and no response predictor has been validated. Candidacy is a clinical judgement for a physician who has assessed you.
Cell therapy has not been studied, and would require specific evaluation, in people with active malignancy, uncontrolled infection, or significant cardiovascular instability.
What Sterling-Certified Partner Clinics Offer
For transparency, separately from the evidence above: Sterling-certified partner clinics in Thailand provide allogeneic umbilical cord-derived MSC preparations under Thai FDA oversight, alongside supporting infusion services. Cell counts, session structure, viability specifications, pricing and adjunct services are commercial and clinical arrangements determined at the clinic. They are not findings from the literature and are not presented here as evidence of effect.
Adjunct offerings — including NAD+ infusion, NK/NKT cell preparations, plasmapheresis and cord blood plasma — have no published clinical evidence supporting their use for frailty, and form no part of the evidence base described on this page.
Any treatment plan is a matter for a qualified physician who has examined you.
Frequently Asked Questions
Is frailty just getting old?
No. It is a specific syndrome of reduced reserve across multiple physiological systems, and it is measurable against defined criteria [2]. Most older adults are not frail — pooled prevalence over 65 is about 10.7% [3].
Can frailty be reversed?
Partly. Pre-frailty responds well to intervention, and established frailty has improved in randomised trials — the strongest example being a 113% strength gain with resistance training in nursing-home residents averaging 87 years old [4]. What has not been shown is that frailty can be prevented outright.
Does stem cell therapy work for frailty?
It has randomised, placebo-controlled support, which is more than most indications in this field can claim. A trial of umbilical cord MSCs improved SF-36 physical function against placebo (p = 0.042) [5], and a 148-patient trial improved six-minute walk distance by 63.4 metres at nine months (95% CI 17.1–109.6; p = 0.0077) [6]. What is unresolved is optimal dose, how long benefit lasts, and whether it changes any hard outcome.
How many cells, and does more work better?
Unresolved, and the evidence conflicts. The Phase 2 CRATUS trial found 100 million cells outperformed 200 million on every physical endpoint [12]. The larger 2026 trial describes a dose-dependent effect [6]. No dose can be called optimal on current evidence.
How long do the benefits last?
Controlled follow-up currently ends at six to nine months [5][6]. Nothing beyond that has been tested.
Do I still need to exercise?
Yes. Progressive resistance training has the largest effect of any intervention studied in frailty [4], and no trial has tested cell therapy as a replacement for it.
Is this anti-ageing treatment?
No. These trials measured walking distance, physical function, quality-of-life scores and inflammatory markers in people who already meet frailty criteria. None studied lifespan, and none supports a claim about extending it.
Is it approved?
Cell therapy for frailty is investigational. It is not approved for this indication in the United States or Europe. Sterling-certified partner clinics in Thailand operate under Thai FDA oversight, which is a different regulatory framework rather than an equivalent approval.