Exosome Evidence Index

Studies / COVID-19 lung disease and inhaled use

Inhaled adipose stem cell vesicles in healthy volunteers

Shi M et al., Journal of Extracellular Vesicles, 2021

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

Safety only: The study looked for harms. It was not designed to show whether the treatment works.

Level 2 of 5: A group was treated and followed, but nobody was left untreated for comparison. Improvement may come from time, other care, or the placebo effect.

See the full key
Design
Dose-escalation safety study
People
24 healthy volunteers
Made from
Fat (adipose) stem cells
How it was given
Inhaled (nebulized), one dose

What they found

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

What limits it

Healthy people, single doses, short-term safety only.

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

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

    Zarrabi M et al., Stem Cell Research & Therapy, 2023. 43 analyzed (8 got cells plus vesicles). Made from: umbilical cord.

    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.

  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.