Treatment & Procedure
Stem cell therapy
Biohacking
Stem cells can renew themselves and turn into other cell types. That makes them one of medicine's great hopes. Between approved stem cell medicine and the offers of longevity clinics, however, there is a large gap.
In brief
What is established is the transplantation of blood stem cells in blood diseases, and since 2024 the US has had the first approved therapy with mesenchymal stromal cells, for a severe immune reaction after transplantation in children. In knee osteoarthritis, cell injections relieved pain in many studies, but in the largest study, with 480 patients, not better than cortisone, and compared with placebo the context effect explains most of the improvement. For anti-aging in healthy people, there is no controlled study. The catch: commercial offers often work with untested preparations, and serious harm up to blindness as well as deaths have been documented.
What it is
In the longevity field, it is mostly about mesenchymal stromal cells, MSC for short. They are obtained from bone marrow, adipose tissue or umbilical cord, in some cases multiplied in the lab, and then injected into the joint or given as an infusion. Some offers use your own cells, which are harvested and processed in the same session; others use donor cells from umbilical cord tissue.
This has to be distinguished from blood stem cell transplantation, for example in leukemia. It has been standard medicine for decades and has little in common with the wellness offers. Legally, processed stem cell preparations in the EU usually count as advanced therapy medicinal products, abbreviated ATMP.
How it is supposed to work
The original idea was that stem cells replace lost tissue, such as cartilage. This has hardly been confirmed in that form. Today, a different explanation is in the foreground: MSC release signaling molecules that dampen inflammation and trigger the body's own repair processes. So they act more as short-lived signal senders than as building material.
For the anti-aging use, the hypothesis is that the body's own stem cell reserves dwindle with age and that fresh cells improve the regenerative capacity of the whole body. This is plausible from cell culture and animal models. It has not been studied in healthy humans.
How to recognize reputable offers
Reputable uses take place either with an approved preparation, in an officially authorized clinical trial or under the hospital exemption at specialized centers such as university hospitals. According to the Paul-Ehrlich-Institut, such individualized uses at specialized centers are free of charge for patients. Warning signs are high upfront payments, treatment of many different diseases with the same preparation, promises of cure, missing information on origin, cell count and quality control, and clinics abroad that advertise getting around the rules.
What is well supported
Stem cell medicine is established in blood diseases. The US authority FDA lists blood stem cells from umbilical cord blood as approved products for disorders of blood formation. In December 2024, the first approval for mesenchymal stromal cells was added, for children with a steroid-refractory acute rejection reaction after transplantation. In the pivotal study with 54 children, 30 percent achieved complete remission after 28 days.
In knee osteoarthritis, there are now 28 randomized trials. Taken together, cell injections relieved pain and improved some everyday functions compared with control injections. In frail older adults, a small phase II study showed that intravenous donor cells were well tolerated and that walking distance increased in one dose group.
What the studies show
Mautner 2023 — the largest knee study
480 people with knee osteoarthritis received one of three cell treatments, bone marrow concentrate, adipose tissue cells or umbilical cord cells, or a cortisone injection. After 12 months, no cell treatment was superior for pain, neither against each other nor against cortisone. On MRI, no group showed a change in the osteoarthritis. No serious procedure-related side effects occurred.
Yin 2025 — how much is context effect?
Analysis of 8 randomized trials with 467 patients in which stem cell injections were compared with placebo. After 6 months, around 63 percent of the pain relief could be attributed to context effects, that is, to expectation, attention and the injection itself. The cells added only a modest additional benefit. The certainty of evidence was low.
Tompkins 2017 — frailty in old age
Double-blind phase II study with 30 frail people, mean age 75.5 years, who received 100 or 200 million donor cells or placebo as an infusion. The primary endpoint was safety; no treatment-related serious side effects occurred. Walking test and physical performance improved only in the 100-million group, immune markers in both dose groups.
Where the data stop
For what longevity clinics sell most often, systemic infusions to rejuvenate healthy people, there is no controlled study. The frailty study involved sick people, was small and, of all things, showed no improvement in physical performance at the higher dose. Cartilage regeneration is not supported: in the largest knee trial the MRI remained unchanged, and the reviews regard the cells as relieving symptoms, not as building tissue.
On top of this comes a fundamental problem. What was tested in studies is a defined preparation with a known cell count and quality control. What is injected in commercial clinics is often not documented. The results therefore cannot simply be transferred.
Status, approval and legal
In Germany, processed stem cell preparations are as a rule advanced therapy medicinal products. They may only be used as an approved medicinal product, in an authorized clinical trial or under the hospital exemption at specialized centers. On March 31, 2025, the European Medicines Agency, the heads of the national medicines agencies and the Paul-Ehrlich-Institut jointly warned against commercial offers with unapproved cell therapies. Health insurers do not pay for longevity stem cell treatments.
Safety
In controlled studies with tested preparations, hardly any serious side effects occurred; local reactions such as swelling and pain in the joint were more frequent than under control. It is different with untested offers. In the New England Journal of Medicine, 3 patients were described who suffered severe and permanent loss of vision after injection of adipose tissue cells into the eye at a US clinic. In Düsseldorf, a private clinic was closed in 2011 after a boy died of a brain hemorrhage following a stem cell injection into the brain. The authorities name as the main risk the lack of control over quality, composition and storage of the preparations.
BK-Score Thin human evidence
| Human evidence | 4 | |
|---|---|---|
| Mechanism | 4 | |
| Safety data | 3 | |
| Hype gap | 1 | |
| Track record of use | 4 |
For anti-aging in healthy people, there is no controlled study. What exists concerns sick people: in age-related frailty, a phase II study with 30 participants, designed primarily for safety, with better physical performance only in the lower dose group; in knee osteoarthritis, 28 randomized trials with pain relief compared with controls, but the largest (Nature Medicine 2023, 480 patients) found no advantage over cortisone after 12 months and no structural change, and compared with placebo, around 63 percent of the pain relief is due to context effects. Serious harm after untested treatments, up to permanent blindness, and deaths are documented; in Germany, a clinic was closed in 2011 after the death of a child. The EMA and the heads of the European medicines agencies, including the Paul-Ehrlich-Institut, warned on March 31, 2025 against commercial offers with unapproved cell therapies.
The score rates the state of knowledge, not the substance. “Safety data 9” means well studied – not harmless.
Subjective assessment by Biohacking Kompakt based on published scoring rules – not a scientific rating and not a medical recommendation. Rules and all ratings (German)
Frequently asked questions about stem cell therapy
Does stem cell therapy work against aging?
There is no controlled study in healthy people on this. A small study in frail older adults showed good tolerability and in part a better walking distance, but only in one of two dose groups.
Does stem cell therapy help with knee osteoarthritis?
Many studies show less pain, but the largest study, with 480 patients, found no advantage over a cortisone injection after one year. Compared with placebo, most of the improvement is due to context effects. Cartilage regeneration is not supported.
Is stem cell therapy allowed in Germany?
Only with approved preparations, in authorized clinical trials or under the hospital exemption at specialized centers. The EMA and the heads of the European medicines agencies, including the Paul-Ehrlich-Institut, explicitly warn against commercial offers with unapproved cell therapies.
What are the risks of stem cell therapy?
With tested preparations in studies, serious side effects are rare. With untested offers, blindness after eye injections and a death after an injection into the brain are documented. The risk lies mainly in uncontrolled quality.
Does health insurance pay for stem cell therapy?
Blood stem cell transplants in blood diseases, yes; longevity or joint offers from private clinics, no. According to the Paul-Ehrlich-Institut, individualized uses under the hospital exemption at specialized centers are free of charge.
How can I recognize a dubious stem cell offer?
Warning signs are high upfront payments, one preparation for many different diseases, promises of cure and missing information on cell origin and quality control. Approved preparations or officially authorized studies are reputable.
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Sources
- Mautner et al., Nat Med 2023 (knee osteoarthritis, phase 3)
- Yin et al., Front Med (Lausanne) 2025 (context effects, meta-analysis)
- Awad et al., Clin Rheumatol 2026 (knee osteoarthritis, 28 RCTs)
- Tompkins et al., J Gerontol A Biol Sci Med Sci 2017 (frailty, phase II)
- Kuriyan et al., N Engl J Med 2017 (vision loss after clinic treatment)
- Paul-Ehrlich-Institut 2025, warning against unapproved ATMP
- FDA 2024, first approved mesenchymal stromal cell therapy
- FDA, consumer alert on regenerative medicine
- ALS Center of the Charité 2011, stem cell treatment at the XCell-Center stopped
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Information only, not medical advice and not a usage or dosage recommendation. Prescription-only and unapproved substances belong in the hands of a physician. Last updated: 2026-10-04.