What Mesenchymal Stem Cells Are
Mesenchymal stem cells, shortened to MSCs and also called mesenchymal stromal cells, are cells that researchers can grow in a laboratory dish.[1] In 2006 the International Society for Cellular Therapy set minimal criteria for calling a cell a human MSC: it must stick to plastic in culture, carry the surface markers CD105, CD73 and CD90 while lacking CD45, CD34, CD14 or CD11b, CD79alpha or CD19 and HLA-DR, and be able to form bone, fat and cartilage cells in a dish.[1]
Researchers are especially interested in what MSCs release.[2] In a 2017 paper, Arnold Caplan argued that the name should change.[2] The studies below were run on MSCs taken from bone marrow[6] and from fat.[5]
At GIOSTAR, the stem cells are ethically sourced from screened donors, and no embryos are involved at any point. For a plain-language introduction to the cells themselves, read what stem cells are and how stem cell research works on the GIOSTAR blog.
What the Studies Cover
The studies below are grouped by the condition each one examined. The condition groups are not a list of anything GIOSTAR treats.
Joints
A 2025 meta-analysis of 8 randomized trials with 502 patients found that MSC injections into the knee improved the WOMAC score, a standard knee questionnaire, at 6 months (a mean difference of 7.44) and at 12 months (10.31) compared with controls.[4] It found no significant difference in adverse events between the groups.[4]
A 2024 review compared two fat-derived preparations: cultured MSCs, and stromal vascular fraction, a mixed cell preparation that is not cultured.[5] Across 31 studies with 1,406 patients, the authors reported that cultured fat-derived MSCs reduced pain from 3 months, and stromal vascular fraction reduced pain from 12 months.[5]
A 2025 review of bone marrow MSCs identified 13 randomized trials and meta-analyzed 11 of them, with 1,150 patients.[6] It found no significant change in pain or function at 1 to 3 months, significant improvement at 6 months that peaked at 12 months, and the best pain results at doses of 25 million cells or fewer.[6]
The largest single knee trial in this guide is a phase 3 randomized, double-blind, placebo-controlled study of 261 adults.[12] At 6 months, the fat-derived MSC group improved more than placebo on pain (25.2 points against 15.5 on the 100-millimeter visual analog scale) and on WOMAC (21.7 points against 14.3).[12] The trial is registered as NCT03990805.[12]
Immune and autoimmune conditions
A 2025 review of 42 randomized trials with 2,183 participants covered rheumatoid arthritis, osteoarthritis, lupus, inflammatory bowel disease, multiple sclerosis and Sjögren's syndrome.[7] The authors reported that MSC transplantation may improve spondyloarthritis, rheumatoid arthritis and primary Sjögren's syndrome.[7]
A 2024 meta-analysis pooled preclinical studies, which are experiments that come before human trials, to examine how MSCs behave in autoimmune disease.[11] Preclinical studies are an early step, and their results do not establish how the same cells act in people.[11]
Lungs
Acute respiratory distress syndrome is a severe lung injury.[8] A meta-analysis of 13 randomized trials with 655 patients examined MSCs in that condition, and covered both safety and efficacy.[8]
A 2017 review of cell therapy for respiratory disease analyzed 204 recipients across eight conditions.[9] In adults, deaths were 71 per 1,000 recipients and 177 per 1,000 controls, a difference the pooled estimate did not show as statistically significant.[9] The same review counted 342 systemic infusions and 57 bronchial instillations.[9]
Liver
A 2025 review of 7 clinical trials in acute-on-chronic liver failure found that MSC recipients had lower MELD scores, a liver severity score, at 4 and 24 weeks than people given conventional treatment.[10]
Brain and nerves
In a randomized, double-blind, placebo-controlled phase 2a trial, four groups of 11 to 13 participants with mild Alzheimer's disease received placebo or one of three MSC dosing schedules.[13] The authors reported safety for single and multiple doses.[13] At 39 weeks, the treated groups combined slowed the decline of whole brain volume by 48.4% compared with placebo (n = 10), and the authors saw a possible link to cognition.[13] They called for larger trials.[13] The trial is registered as NCT05233774.[13]
A phase 3 randomized, placebo-controlled trial of mesenchymal stem cells induced to secrete high levels of neurotrophic factors in amyotrophic lateral sclerosis, or ALS, did not meet its primary endpoint.[14] At 28 weeks, 33% of treated participants and 28% of placebo participants met the clinical response criteria.[14] In a pre-specified subgroup of 58 participants with less severe disease, the rates were 35% and 16%, a difference that was not statistically significant.[14] The treatment was well tolerated.[14]
Diabetes
A phase I/II randomized, placebo-controlled trial enrolled 21 patients with newly diagnosed type 1 diabetes.[15] The authors reported fewer hypoglycemic episodes after MSC transplantation, improved HbA1c, a blood test that reflects average blood sugar over about three months, and called the treatment safe.[15] The trial is registered as NCT04078308.[15]
A condition outside the joints
The ADMIRE-CD follow-up is a phase 3 study of 40 patients with perianal fistulizing Crohn's disease.[16] At week 104, clinical remission was reported in 14 of 25 treated patients (56%) and 6 of 15 control patients (40%).[16] Seven treatment-emergent serious adverse events were reported through week 104.[16] The authors noted that only a small number of patients entered the extended follow-up.[16] The trial is registered as NCT01541579.[16]
Safety: What Studies Track
The 2017 respiratory review pooled serious adverse events across cell therapies.[9] The long-term Crohn's follow-up reported seven serious adverse events through week 104.[16] The ALS trial reported no safety concerns.[14] The 2025 knee review found no significant difference in adverse events between MSC and control groups.[4]
How to Read a Mesenchymal Stem Cell Study
A few details tell you much about any study:
- The cell source. Cultured fat-derived MSCs and stromal vascular fraction are different preparations, and the 2024 review found their timing of benefit differed.[5]
- The dose. The 2025 bone marrow review found the best pain results at 25 million cells or fewer, so a dose claim means little without its number.[6]
- The size. A 21-patient trial and a 261-adult trial do not carry the same weight.[15][12]
- The follow-up. The Crohn's follow-up ran to 104 weeks, and the knee reviews report results at 6 and 12 months.[16][4]
- The registration. The knee phase 3 study is registered as NCT03990805, so its design and outcomes are listed publicly.[12]
Where to Find Mesenchymal Stem Cell Studies
Start with a search for 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.
Read the companion guides, stem cell research and the knee and stem cell research and the shoulder. Two sibling guides cover other cell sources: umbilical cord stem cell research and exosome research.
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.[3] 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.[3] 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).
