What Exosomes Are
Exosomes are small vesicles that cells release.[2] Researchers group them with other cell-released particles under the term extracellular vesicles, or EVs.[1] The 2023 guidelines for the field (MISEV2023) describe approaches to vesicle research and their advantages and limitations.[1]
Mesenchymal stem cells release exosomes.[2] A 2020 review described how the paracrine effects of these cells, meaning the signals they send to nearby cells, are partly carried by exosomes.[2]
What Human Studies Show
Registries list many EV studies.[3] A 2024 critical review catalogued 471 EV-related clinical trials, with indications for more than 200 diseases.[3]
A 2024 meta-analysis of human EV-based therapy trials concluded that EV-based therapy is safe and presents a promising opportunity.[4] The authors warned that manufacturing methods, study designs and reporting varied widely, and called for standard reporting of how vesicles are isolated and characterized.[4]
A 2026 meta-analysis of human clinical trials in aesthetic medicine assessed risk of bias with the Cochrane ROB2 tool.[5] The authors reported consistent improvements in skin and hair outcomes, and called for further investigation.[5]
A 2025 meta-analysis of 48 eligible studies with 1,773 patients, 31 of them meta-analyzed, covered cells, vesicles and secretomes in acute respiratory distress syndrome.[6] It found lower all-cause death with the cell-derived treatments than with routine care, and the reduction was seen only for deaths within one month.[6]
Randomized trials
A phase 2 randomized, placebo-controlled trial of bone marrow MSC-derived vesicles in patients with COVID-19 respiratory failure reported no treatment-related adverse events.[11] Its main intention-to-treat result, 60-day mortality, was not statistically significant (p = 0.1343).[11] The abstract also reports post hoc subgroup analyses in which 60-day mortality was decreased with the 15 mL dose compared with placebo.[11] The trial is registered as NCT04493242.[11]
A 2025 randomized study of umbilical cord MSC exosomes in knee osteoarthritis combined laboratory work with a clinical part.[12] In the laboratory and animal experiments, the authors reported that the exosomes reduced the inflammatory response of cartilage and promoted its regeneration.[12] In the clinical part, the authors found a degree of effectiveness on clinical scores and MRI.[12]
A 2025 randomized trial of topical MSC exosome eye drops in dry eye related to Sjögren's syndrome gave eight eyes the treatment and eight eyes a control solution.[13] Treated eyes showed lower ocular surface disease scores, higher tear secretion and longer tear-film break-up time than control eyes.[13]
Registered studies
ClinicalTrials.gov lists a registered study of umbilical cord MSC exosomes for hair growth in androgenetic alopecia, with an enrollment of 50 and an active, not recruiting status.[14] A second registered phase 1 study of a mesenchymal cell exosome solution in ALS and other motor disorders lists an enrollment of 70 and a completed status.[15] Registry entries show design and status, not results.[14][15]
What Preclinical Studies Show
A 2021 systematic review of preclinical studies of MSC-derived vesicles reviewed how that work was designed.[7]
A 2025 meta-analysis of preclinical studies found that MSC-derived vesicles significantly reduced liver enzymes AST and ALT, and triglycerides, in models of nonalcoholic fatty liver disease.[8]
A 2024 meta-analysis of 29 preclinical studies found that MSC-derived vesicles increased follicle counts in models of primary ovarian insufficiency.[9]
A 2022 meta-analysis of 12 preclinical bone-injury studies (13 included) found that MSC-derived vesicles improved bone volume by a mean of 22.2%.[10] The authors noted that heterogeneity between studies and possible reporting bias limit confidence in the size of the benefit.[10]
How to Read an Exosome Study
A few details tell you much about any study:
- The source and preparation. Vesicles made from different cells, or prepared in different ways, are not directly comparable.[4] The 2024 meta-analysis of human trials called for standard reporting of isolation and characterization.[4][1]
- The model. Animal and cell results are an early step, and the preclinical meta-analyses above come from animal models.[9][10]
- The size. The dry eye study assigned 8 eyes to each group, a small number.[13]
- The registration. Registered studies such as NCT06697080 and NCT07105371 list their status and enrollment, which is not the same as published results.[14][15]
Where to Find Exosome Studies
Start with a search for exosome studies on ClinicalTrials.gov, and read published work 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 and the umbilical cord stem cell research guide.
GIOSTAR's exosome service is described on our exosome service page. This guide describes research only, and it does not describe what that service will do for any reader.
Regulatory Status
A 2026 review of FDA regulation of biologics finds that enforcement of oversight has been uneven.[16] Our exosome 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).
