Exosome Evidence Index

Studies / COVID-19 lung disease and inhaled use

Stem cells with or without added vesicles for COVID-19 ARDS

Zarrabi M et al., Stem Cell Research & Therapy, 2023

No benefit over controlStrength of design, level 3 of 5: Controlled trial

No benefit over control: The treated group did no better than placebo or the comparison.

Level 3 of 5: Treated patients were compared with a control: placebo, another treatment, or the untreated side of the face. Most exosome trials at this level are small and short.

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Design
Randomized controlled trial, three groups
People
43 analyzed (8 got cells plus vesicles)
Made from
Umbilical cord
How it was given
Stem cell infusion, then one dose of vesicles

What they found

Both treated groups had lower inflammatory markers than the control group, with no serious adverse events. A 2025 review of the trial reports no significant difference between cells alone and cells plus vesicles.

What limits it

Only 8 patients got vesicles, and always after whole stem cells, so this trial cannot show what vesicles do on their own.

Read the study

Reviewed by Tomaz Mesar, MD. Last reviewed October 2026. No exosome product is FDA-approved for any use. Before you book a treatment

Other studies of covid-19 lung disease and inhaled use

  1. Mixed or short-lived resultStrength of design, level 3 of 5: Controlled trial

    Bone marrow stem cell vesicles (ExoFlo) for respiratory failure from COVID-19

    Lightner AL et al., CHEST, 2023. 102 people. Made from: bone marrow.

    No treatment-related adverse events. Lower 60-day mortality was seen in the higher-dose group and in a subgroup of patients aged 18 to 65.

  2. Safety onlyStrength of design, level 2 of 5: Study without a control group

    Inhaled adipose stem cell vesicles in healthy volunteers

    Shi M et al., Journal of Extracellular Vesicles, 2021. 24 healthy volunteers. Made from: fat (adipose) stem cells.

    All doses were well tolerated. Two people had a brief, mild slowing of heart rate that was not linked to dose.

  3. Improvement reported, no control groupStrength of design, level 2 of 5: Study without a control group

    Bone marrow stem cell exosomes (ExoFlo) for severe COVID-19

    Sengupta V et al., Stem Cells and Development, 2020. 24 people. Made from: bone marrow.

    Oxygen levels, clinical status, and lab markers improved, survival was 83%, and no adverse events were seen within 72 hours.

  4. Improvement reported, no control groupStrength of design, level 2 of 5: Study without a control group

    Inhaled adipose stem cell exosomes for severe COVID-19

    Zhu Y et al., Stem Cell Research & Therapy, 2022. 7 people. Made from: fat (adipose) stem cells.

    All patients tolerated treatment. Lymphocyte counts rose slightly, and lung lesions on CT regressed to varying degrees.