What Umbilical Cord Stem Cells Are
Umbilical cord stem cells are mesenchymal stem cells, or MSCs, taken from the umbilical cord.[4][10] Researchers draw them from the umbilical cord itself[4] and from cord blood.[10] In 2006 the International Society for Cellular Therapy set minimal criteria for calling a cell a human MSC, including that it sticks to plastic in culture and can form bone, fat and cartilage cells in a dish.[1]
At GIOSTAR, the stem cells are ethically sourced from screened donors, and no embryos are involved at any point. For a plain-language introduction, read what stem cells are and where stem cells come from and donor screening on the GIOSTAR blog.
Safety Across Many Trials
A 2026 meta-analysis of 42 randomized trials with 2,280 patients examined the safety of cord-derived MSCs given intravascularly.[3] The only signal was more fever, with a relative risk of 2.34 (95% CI 1.02 to 5.35).[3] No other prespecified adverse event showed a harm signal, and no included trial was stopped early for safety concerns.[3] The authors concluded that UC-MSC therapy appears safe for study in heterogeneous patient populations.[3]
What the Studies Cover
Joints
A 2025 review of 8 studies with 688 participants on umbilical cord-origin MSCs for osteoarthritis found that the pooled pain score fell at 6 months, but not significantly (p = 0.28).[4]
A 2024 review of 3 randomized studies found lower WOMAC knee scores in the cord-cell groups, a mean difference of 25.85 points (p = 0.001), and higher Lysholm knee scores, up 18.33 points.[5] Three randomized studies are a small base for firm conclusions.[5]
A phase I/II randomized trial of 26 patients with knee osteoarthritis compared a single dose and a repeated dose of cord MSCs with hyaluronic acid, a common joint injection.[13] At 12 months, the repeated-dose group had lower WOMAC scores than the hyaluronic acid group (4.2 against 15.2, p = 0.05).[13] MRI scores did not differ between groups.[13] The trial is registered as NCT02580695.[13]
Blood sugar and type 1 and type 2 diabetes
A 2025 meta-analysis of 8 clinical trials with 334 patients found that cord MSCs lowered HbA1c, a blood test of average blood sugar, by a mean of 1.06 points.[6] Fasting C-peptide, a marker of the insulin the body makes, was inconsistent across studies and favored placebo.[6]
A single-center, double-blind, randomized phase II trial of 91 adults with type 2 diabetes gave three intravenous infusions of cord MSCs or placebo, four weeks apart.[14] At 48 weeks, 20% of the cord-cell group reached the primary endpoint against 4.55% of placebo recipients (p < 0.05).[14] Insulin reduction was 27.78% in the cord group against 15.62% on placebo.[14] The trial is registered as NCT02302599.[14]
Lungs and COVID-19
A 2023 meta-analysis of 7 randomized trials with 328 patients with COVID-19 pneumonia examined cord MSCs against controls.[8]
A double-blind, randomized phase 1/2a trial of 24 subjects with COVID-19 acute respiratory distress syndrome found no serious adverse events related to cord-MSC infusions.[16] Survival at 31 days, a secondary endpoint, was 91% in the treated group and 42% in controls (P = 0.015).[16]
Heart
A 2023 meta-analysis pooled 3 randomized trials with 201 patients who had heart failure or acute heart attack.[9] At 12 months the cells improved ejection fraction, the heart's pumping measure, but the authors found no meaningful effect on readmission or mortality.[9]
A phase 1/2 randomized trial of 30 patients with reduced ejection fraction heart failure gave intravenous cord MSCs at 1 million cells per kilogram or placebo, 15 patients per group.[15] The trial is registered as NCT01739777.[15]
Aging and frailty
A phase I/II placebo-controlled trial of cord tissue MSCs in aging frailty reported greater improvement in the SF-36 physical component score than placebo (p = 0.042).[17] EQ-VAS scores improved at 2 months (p = 0.023) and through 6 months (p = 0.002), compared with placebo.[17] The authors called the approach safe.[17] The trial is registered as NCT04314011.[17]
Limb circulation and foot ulcers
A 2026 meta-analysis of 6 randomized studies with 380 patients looked at cord MSCs for diabetic foot ulcers and peripheral artery disease, a narrowing of the arteries that reduces blood flow to the legs.[7]
Cartilage from cord blood
A 2022 meta-analysis of cord blood-derived MSCs for cartilage repair pooled studies covering 570 patients.[10]
Animal and mouse studies
A 2022 network meta-analysis of 40 animal studies found that high doses of cord MSCs, at least 1 million cells, did better than low doses in models of spinal cord injury.[11]
A 2026 meta-analysis of 13 studies in mice found that cord MSCs improved spatial learning and memory in Alzheimer's model mice and lowered brain beta-amyloid levels.[12] Mouse results do not establish results in people.[12]
How to Read an Umbilical Cord Stem Cell Study
A few details tell you much about any study:
- The cell source. Cord tissue and cord blood are different starting materials.[4][10]
- The dose. The heart failure trial used 1 million cells per kilogram, and the spinal cord review found high doses did better than low doses in animals.[15][11]
- The size. A review of 42 randomized trials and a review of 3 randomized studies do not carry the same weight.[3][5]
- The follow-up. The type 2 diabetes trial ran to 48 weeks, and the knee trial reported results at 12 months.[14][13]
- The species. Mouse and animal results are an early step, not evidence of results in people.[12][11]
Where to Find Umbilical Cord Stem Cell Studies
Start with a search for umbilical cord mesenchymal stem cell studies on ClinicalTrials.gov, and read published results on PubMed. Every source in this guide is listed under References with its PubMed and DOI links.
This guide sits beside the other research guides. Read the mesenchymal stem cell research guide, the knee guide, the shoulder guide, and the exosome research guide.
This guide describes research. For GIOSTAR's own stem cell therapy, see our stem cell therapy page.
Regulatory Status
A 2026 review describes stem cell clinics as arguably subject to FDA oversight.[2] A 2026 review of FDA regulation of biologics describes that oversight as arguably applicable at several levels, and finds that it has been enforced unevenly.[2] Our stem cell therapy is not approved by the FDA.
Further reading: the FDA's consumer page on regenerative medicine therapies, fda.gov (a regulator page; not a numbered reference).
