The controlled facial trials of topical exosomes set their primary endpoints at 12 weeks, and the earliest reported difference between the exosome side and the control side came at the 1-month visit of a six-person pilot [3, 4, 5, 7]. The longest follow-up in those trials was 6 months, so the published record describes a window of 1 to 6 months and nothing beyond it [6, 7]. How long a vial keeps in storage is a separate question of shelf life, outside the scope of these trials.
Visit schedules and the pace of skin biology together give the clearest timeline, first for the facial trials and then for the hair studies. Patients weighing an exosome add-on and the practice staff who answer them will find every figure below attached to the study that produced it. ExaVeyra Sciences supplies exosome material to licensed practices; the practitioner decides whether, when and how often it is used.
Regulatory status
The FDA stated in its 2019 public safety notification that there are currently no FDA-approved exosome products, and its 2020 consumer alert, current as of 2024, repeats that statement [17, 19]. ExaVeyra supplies exosome material for topical aesthetic use by licensed practitioners, and for laboratory research and clinical research conducted under an IND, described by its available formats. Whether a patient receives the material, when, and on what schedule is a decision for the licensed practitioner, and every timeline in this article is a study observation.
Understanding the question as a visit schedule in published trials
A trial can only report a change at the visits it scheduled, so the timeline the literature gives for how long exosomes take to work is a list of visit dates. Gaebe and colleagues reviewed 16 facial studies with 503 participants in 2026 and reported that most found improvement in at least one skin-quality outcome, while rating the certainty of that evidence low or very low [1].
Stack and colleagues reached a similar position from 39 human studies in 2026, with a pooled facial wrinkle reduction of 20.2 percent and a note that nonstandardized protocols limit how far any figure generalizes [2]. A pooled percentage carries no clock of its own, which is why this article returns to the individual trials and the weeks at which they looked.
Two features of a schedule matter most: the first visit at which a difference was measured, and the last visit the study held. The first sets the earliest point a trial could detect anything, and the last sets the limit of what anyone can say about duration.
Skin biology sets the earliest plausible time course
The epidermis replaces itself over weeks. Weinstein and colleagues measured a cell cycle of 311 hours in normal human epidermis in 1984 and described renewal in three compartments, and Iizuka recalculated the total turnover time from that data at 47 to 48 days in 1994, in place of the 39 days often quoted [14, 15].
Collagen moves more slowly. Orringer and colleagues took serial biopsies after focal CO2 laser resurfacing of photodamaged forearms in 28 adults in 2004 and reported that type I and type III procollagen messenger RNA peaked at 7.5 and 8.9 times baseline 21 days after the procedure and stayed elevated for at least 6 months [12]. El-Domyati and colleagues biopsied ten participants after microneedling sessions in 2015 and reported significant increases in collagen types I, III and VII by the 3-month biopsy [13].
| Process | Time course reported | Source and design | What it implies for a timeline |
|---|---|---|---|
| Epidermal renewal | Turnover calculated at 47 to 48 days; 39 days often quoted | Iizuka 1994, recalculation of Weinstein 1984 kinetic data [14, 15] | Surface texture and hydration changes are plausible within 4 to 8 weeks |
| Procollagen synthesis after a resurfacing procedure | Peak at day 21, elevated for at least 6 months | Orringer 2004, serial forearm biopsies after focal CO2 resurfacing [12] | Dermal changes are read in months, so a 12-week endpoint is an early read |
| Collagen deposition after microneedling | Significant increases at the 3-month biopsy | El-Domyati 2015, six sessions, n = 10 [13] | The procedure itself drives a months-long course that any add-on rides on |
Those time courses belong to the skin and the procedure, and every facial trial below paired the exosome material with microneedling, radiofrequency microneedling or a fractional laser. A measured change at 4 or 12 weeks therefore sits inside the procedure’s own remodeling window, and the split-face design is what separates the add-on from the procedure.
Facial trials report measured differences between 4 and 12 weeks
Kwon and colleagues ran a double-blind split-face trial in 25 adults with acne scars in 2020, with three fractional CO2 sessions three weeks apart and an exosome gel on one side, and reported a 32.5 percent reduction in scar score on that side against 19.9 percent on the control side at the 12-week visit [3]. Park GH and colleagues used the same 12-week frame after microneedling in 28 adults in 2023 and reported a higher global aesthetic score on the exosome side at the final visit, with instrument-measured gains in wrinkles, elasticity, hydration and pigmentation [4].
Yen and colleagues assessed 60 adults at baseline, week 4 and week 12 after radiofrequency microneedling in 2026, with the primary endpoint at week 12, where the wrinkle score improved by 12.59 points on the vesicle side and 9.28 points on the control side, a paired difference of 3.32 points [5]. The authors wrote that the unblinded design and 12-week follow-up call for cautious interpretation.
| Study | Design and size | Sessions and spacing | Assessment visits | Result at the visit reported |
|---|---|---|---|---|
| Kwon 2020 [3] | Double-blind randomized split-face, n = 25 | 3 fractional CO2 sessions, 3 weeks apart | Follow-up to 12 weeks | 32.5 percent scar-score reduction on the exosome side against 19.9 percent |
| Park GH 2023 [4] | Randomized split-face, saline control, n = 28 | 3 microneedling sessions, 3 weeks apart | Final visit at 12 weeks | Higher global aesthetic score and instrument gains on the exosome side |
| Yen 2026 [5] | Randomized split-face, unblinded, n = 60 | Radiofrequency microneedling; spacing not in the abstract | Baseline, week 4, week 12 | Paired wrinkle-score difference of 3.32 points at week 12 |
| Estupiñan 2025 [6] | Investigator-blinded split-face, PRP comparator, n = 15 | 3 radiofrequency microneedling sessions | 3 and 6 months | Equal improvement on both sides; collagen I increased on histology in both |
| Huang 2026 [7] | Split-face pilot, random side assignment, n = 6 | Needling radiofrequency; spacing not in the abstract | 1, 3 and 6 months | Greater wrinkle reduction on the vesicle side at 1 and 3 months |
Read together, the earliest reported difference sits at the 1-month visit in the smallest study, the largest assessed at week 4 and reported its between-side difference at week 12, and the most common endpoint is week 12 [5, 7]. No trial in this set scheduled a visit in the first days after a session, so the published record has no measurement of an immediate effect.
Recognizing what the evidence does not yet show
- No controlled facial study followed participants beyond 6 months after the last session, so there is no published estimate of how long a measured change persists [6, 7]
- Gaebe and colleagues concluded in 2026 that short follow-up and inconsistent outcome assessment preclude definitive conclusions across the 16 studies they reviewed [1]
- The trials used different vesicle sources, different procedures and different visit schedules, so their timelines cannot be merged into one expected course [2]
- Two of the five facial studies enrolled 15 or fewer participants, and the 60-person study was unblinded [5, 6, 7]
- No facial trial scheduled a visit within the first week, so the earliest possible change remains unmeasured
- Knauer and colleagues reported in 2026 that 20 commercial products carried minimal information on isolation, processing or shelf life, so a timeline measured with one product is not evidence for another [16]
- The hair studies with the longest follow-up were single-arm, so their 9- and 12-month figures have no control comparison [9, 10]
Each of those gaps narrows the question to what a specific study measured with a specific product on a specific schedule. That is a more modest answer than a search result usually offers, and it is the one the literature supports.
Six months is the longest follow-up the split-face studies measured
Estupiñan and colleagues followed 15 adults with mild to moderate photoaging for 6 months after three radiofrequency microneedling sessions in 2025, with topical exosomes on one side and PRP on the other, and reported equal improvement in wrinkling, dyschromia, erythema and texture on both sides, with histology showing increased collagen I and glycosaminoglycans in both arms [6]. Six months was the last visit the trial held.
Huang and colleagues assessed six participants at 1, 3 and 6 months after needling radiofrequency in 2026 and reported sustained remodeling at 6 months on the vesicle side, with rebound worsening on the side that received the procedure alone [7]. The authors describe the result as preliminary, and a six-person study cannot settle the question of duration.
Short follow-up and inconsistent outcome assessment preclude definitive conclusions, in the words of the 2026 systematic review of 16 facial studies [1].
For anyone searching how long exosome results last, the published answer is that the trials stopped measuring at 6 months. A statement that a result lasts a year or more has no support among the controlled studies located for this article.
Hair studies measured endpoints between 24 weeks and 12 months
The hair literature runs on a longer clock because a follicle cycle is measured in months. Lee and colleagues followed 30 adults with androgenetic alopecia for 24 weeks in 2024 and reported a significant increase in total hair density with improved photographic assessment and no severe adverse reactions [8].
Koumprentziotis and colleagues examined 20 adults with pattern hair loss by trichoscopy at 3, 6 and 9 months after microneedling radiofrequency with topical exosomes in 2025 and reported increases in mean hair density and diameter, with a median follow-up of 10 months [9]. Wan and colleagues followed 16 men for 12 months after scalp microneedling with a topical exosome product in 2025 and reported a mean increase of 35 hairs per square centimeter, a single-arm result its authors graded as level IV evidence [10].
The reviews temper those figures. Malih and colleagues reported in a 2026 systematic review of 39 studies that early clinical work found hair density improvements of 8 to 20 percent, limited by small samples, retrospective designs and missing control groups, and Stack and colleagues pooled a 23.6 percent density improvement across heterogeneous protocols [2, 11].
Reading the exosome results timeline across procedures and products
The visit at which a change first appears depends on the procedure that preceded the application, the outcome measured and the product used. Instrument-measured hydration and texture can move within the epidermal turnover window, while scar and wrinkle scores that depend on collagen follow the months-long course Orringer and colleagues described [12, 14].
Products differ as well. Knauer and colleagues surveyed 20 commercial topical exosome products in 2026 and reported minimal information on isolation, processing or shelf life, and the same scoping review found that ten of 18 human studies paired exosomes with a delivery procedure while eight used topical application alone [16]. A timeline from a study that used one source and one procedure is evidence for that pairing and no other.
- Ask which procedure preceded the application in the study being quoted, and whether the same procedure is planned
- Ask at which visit the study first measured a difference, and at which visit it stopped
- Ask whether the comparison was a split-face control or a single-arm before-and-after series
- Ask what product the study used and what documentation the product in the practice carries, including its lot number and certificate of analysis
The practitioner sets the plan and the practice keeps the record
The FDA states that microneedling devices are not approved for delivering cosmetics, topical medications, drugs or blood products into the skin, and that the risks of combining the devices with other products are not known [18]. Within that frame, the number of sessions, the spacing and the follow-up visits for any patient are set by the licensed practitioner, who can read the schedules above against the procedure planned.
A practice that photographs at the same visit points the trials used, at week 4, week 12 and 6 months, builds a record it can compare with the literature. Each ExaVeyra vial carries its lot number, a certificate of analysis with serology exists for every lot, and the certificate, characterization panel and cold-chain records are available on request, so the session record can name the exact material used.
Access works through a verified account. Anyone may ask the scientific team a question or apply without an NPI, NPI review takes 1 to 3 business days, and verification gives access to the practitioner portal, product documentation and pricing. Orders ship overnight frozen on dry ice and arrive in 1 to 3 business days, with the lot documents ready for the practice file.
The published timeline is short and the studies are small, and that is a reason for careful reading and continued attention. Each new trial with a longer visit schedule extends the window practices can describe to their patients, and a practice that keeps clean records from the first session will be ready to read those trials against its own experience.
Aviso Educativo: This article is for educational purposes only and does not constitute medical or legal advice. It does not identify any material, compound, device setting or protocol as safe, effective or appropriate for any patient, and it is not intended to diagnose, treat, cure, or prevent any disease. Questions about a treatment belong with the reader’s own licensed provider. Exosome material is supplied for topical aesthetic use by licensed practitioners. No exosome product is FDA-approved for any use, and ExaVeyra Sciences makes no statement about administration, route, or outcome. Compounded medications are not FDA-approved. They are prepared by a 503A compounding pharmacy licensed by the Texas State Board of Pharmacy for an individual patient against that patient’s prescription, and are available to NPI-verified licensed practitioners only, in the states where the pharmacy is licensed. Product, device and brand names mentioned are trademarks of their respective owners and are used only to identify the products discussed. Their mention is not an endorsement, and those owners have not reviewed or endorsed this article. ExaVeyra Sciences is a supplier and takes no part in any diagnosis, treatment decision, or plan of care. Findings described are attributed to the peer-reviewed literature, trial registries and agencies cited. The content of these guides is provided for general informational purposes only. It does not constitute legal, medical, or regulatory advice, and does not establish that any particular product or practice is compliant. Regulatory requirements vary by state and depend on the circumstances of each practice. Each practitioner should consult their own legal counsel and the applicable state licensing boards before acting on anything stated here.
Referencias
- 1.Gaebe K, Lowe K, Bosnalie D, Khoury S, Villemure Poliquin N, Nichols A. Effectiveness and Safety of Extracellular Vesicle-Based Therapies for Nonsurgical Facial Rejuvenation: A Systematic Review. Facial Plast Surg Aesthet Med. 2026. Published online ahead of print. PMID 42487416. doi:10.1177/26893614261457879PRISMA systematic review with risk-of-bias and GRADE assessment, searches January 2000 to June 2025; 16 studies, 503 participants. Carries in this article: most studies reported improvement in at least one skin-quality outcome, no serious adverse events were reported, and the authors concluded that short follow-up and inconsistent outcome assessment preclude definitive conclusions. Disclosure: academic authors (Canada); no conflict statement in the PubMed record.
- 2.Stack ER, Spongberg C, Braud SC, Stanton WN, Elway M. Clinical Advances in Exosome-Based Therapies for Aesthetic Medicine: A Systematic Review and Meta-analysis of Human Clinical Trials. Aesthet Surg J. 2026;46(12 Suppl 2):S13-S25. PMID 41800726. doi:10.1093/asj/sjaf178Systematic review and random-effects meta-analysis, searches to February 2025; 39 human studies, 26 on skin and 13 on hair. Carries in this article: pooled facial wrinkle reduction of 20.2 percent and pooled hair density improvement of 23.6 percent, with heterogeneity and nonstandardized protocols noted by the authors, the reason no single timeline can be read from the pooled figures. Disclosure: published in a journal supplement on exosomes; no funding statement in the PubMed record.
- 3.Kwon HH, Yang SH, Lee J, Park BC, Park KY, Jung JY, et al. Combination Treatment with Human Adipose Tissue Stem Cell-derived Exosomes and Fractional CO2 Laser for Acne Scars: A 12-week Prospective, Double-blind, Randomized, Split-face Study. Acta Derm Venereol. 2020;100(18):adv00310. PMID 33073298. PMC9309822. doi:10.2340/00015555-3666Prospective, double-blind, randomized, split-face trial over 12 weeks, three fractional CO2 laser sessions with an exosome gel on one side and a control gel on the other (Korea); n = 25. Carries in this article: the 12-week endpoint, where the exosome side showed a 32.5 percent reduction in scar score against 19.9 percent on the control side. Disclosure: the gels were supplied by the exosome manufacturer; the authors declared no conflicts of interest.
- 4.Park GH, Kwon HH, Seok J, Yang SH, Lee J, Park BC, et al. Efficacy of combined treatment with human adipose tissue stem cell-derived exosome-containing solution and microneedling for facial skin aging: A 12-week prospective, randomized, split-face study. J Cosmet Dermatol. 2023;22(12):3418-3426. PMID 37377400. doi:10.1111/jocd.15872Prospective, randomized, split-face study over 12 weeks, three microneedling sessions three weeks apart with an exosome solution on one side and saline on the other (Korea); n = 28. Carries in this article: the higher global aesthetic score on the exosome side at the final 12-week visit and the instrument-measured gains in wrinkles, elasticity, hydration and pigmentation reported at that visit. Disclosure: National Research Foundation of Korea grants listed in the PubMed record.
- 5.Yen C, Huang H, Lin C. Radiofrequency Microneedling Combined With Topical Extracellular Vesicle Preparation for Facial Rejuvenation: A Randomized Split-Face Controlled Study. J Craniofac Surg. 2026. Published online ahead of print. PMID 42635327. doi:10.1097/SCS.0000000000013266Randomized split-face study, unblinded, radiofrequency microneedling on both sides with a topical vesicle preparation on one; n = 60. Carries in this article: assessments at baseline, week 4 and week 12, a week-12 primary endpoint with a paired wrinkle-score difference of 3.32 points favoring the vesicle side, and the authors’ caution about the unblinded design and 12-week follow-up. Disclosure: the authors reported no conflicts of interest.
- 6.Estupiñan B, Ly K, Goldberg DJ. Adipose Mesenchymal Stem Cell-Derived Exosomes Versus Platelet-Rich Plasma Treatment for Photoaged Facial Skin: An Investigator-Blinded, Split-Face, Non-Inferiority Trial. J Cosmet Dermatol. 2025;24(5):e70208. PMID 40414798. PMC12104007. doi:10.1111/jocd.70208Investigator-blinded split-face non-inferiority trial, three radiofrequency microneedling sessions with topical exosomes on one side and PRP on the other, in adults with mild to moderate photoaging (USA); n = 15, assessments at 3 and 6 months. Carries in this article: equal improvement on both sides and histology showing increased collagen I and glycosaminoglycans in both arms, with 6 months the last visit. Disclosure: the authors declared no conflicts of interest.
- 7.Huang PP, Chih PL, OuYang SY. Preliminary Insights From a Split-Face Study on Skin Quality Changes After Needling Radiofrequency With or Without a Plant-Derived Exosome-Based Formulation Over 6 Months. Aesthet Surg J. 2026;46(Suppl 2):S62-S72. PMID 41800727. doi:10.1093/asj/sjaf253Prospective split-face study with random side assignment, needling radiofrequency on both sides and a plant-derived vesicle formulation on one; n = 6, assessed at baseline and at 1, 3 and 6 months. Carries in this article: greater wrinkle reduction on the vesicle side at 1 and 3 months, sustained remodeling at 6 months, and rebound worsening on the side that received needling radiofrequency alone. Disclosure: no funding statement in the PubMed record; the authors describe the findings as preliminary.
- 8.Lee E, Choi MS, Cho BS, Won YJ, Lee JH, Kim SR, et al. The efficacy of adipose stem cell-derived exosomes in hair regeneration based on a preclinical and clinical study. Int J Dermatol. 2024;63(9):1212-1220. PMID 39155501. doi:10.1111/ijd.17406Laboratory study of dermal papilla cells and hair follicle organ culture, followed by a clinical study in adults with androgenetic alopecia over 24 weeks; n = 30. Carries in this article: the 24-week endpoint, where the authors reported a significant increase in total hair density, improved photographic assessment and no severe adverse reactions. Disclosure: several authors share affiliations with the exosome developer; see the article for the full statement.
- 9.Koumprentziotis IA, Kroumpouzos E, Delavar S, Kroumpouzos G. Microneedling radiofrequency followed by topical exosome application therapy for pattern hair loss: A scoping review and prospective study. Clin Dermatol. 2025;43(5):742-751. PMID 40744280. doi:10.1016/j.clindermatol.2025.07.006Scoping review (two microneedling radiofrequency studies and nine exosome studies) plus a prospective single-arm series of adults with pattern hair loss; n = 20, trichoscopy at baseline and at 3, 6 and 9 months, median follow-up 10 months. Carries in this article: the visit schedule and the reported increases in mean hair density and diameter with no adverse events. Disclosure: the authors declared no financial interests.
- 10.Wan J, Kim SB, Cartier H, Garson S, Frank K, Haykal D, et al. [A prospective study of exosome material applied for androgenetic alopecia]. Aesthetic Plast Surg. 2025;49(11):3151-3156. PMID 40146273. doi:10.1007/s00266-025-04817-9Prospective open-label single-arm study of men aged 36 to 45 with mild to moderate androgenetic alopecia, scalp microneedling followed by a topical exosome product; n = 16, 12-month follow-up. Carries in this article: the mean increase of 35 hairs per square centimeter at 12 months and mild scalp tenderness resolving within 48 hours, a level IV single-arm result. Disclosure: the authors declared no conflicts of interest; the product maker is named in the methods.
- 11.Malih S, Yang P, Jalise SZ, Sheykhhasan M. Exosome-driven treatments for hair regrowth in androgenetic alopecia: a systematic review of preclinical studies, clinical experiments, safety, and future prospects. Mol Biol Rep. 2026;53(1):1046. PMID 42377704. doi:10.1007/s11033-026-12255-2Systematic review of preclinical and clinical studies published 2019 to 2025; 39 studies. Carries in this article: early clinical studies reported hair density improvements of 8 to 20 percent, with the evidence limited by small samples, retrospective designs, missing control groups and inconsistent outcome measures. Disclosure: the authors declared no competing interests.
- 12.Orringer JS, Kang S, Johnson TM, Karimipour DJ, Hamilton T, Hammerberg C, et al. Connective tissue remodeling induced by carbon dioxide laser resurfacing of photodamaged human skin. Arch Dermatol. 2004;140(11):1326-1332. PMID 15545540. doi:10.1001/archderm.140.11.1326Serial biopsy study of photodamaged forearm skin after CO2 laser resurfacing in human volunteers. Carries in this article: type I and type III procollagen messenger RNA peaked at 7.5 and 8.9 times baseline 21 days after resurfacing and remained elevated for at least 6 months, the reason collagen outcomes are read in months. Disclosure: non-US government research support listed in the PubMed record.
- 13.El-Domyati M, Barakat M, Awad S, Medhat W, El-Fakahany H, Farag H. Multiple microneedling sessions for minimally invasive facial rejuvenation: an objective assessment. Int J Dermatol. 2015;54(12):1361-1369. PMID 26096653. doi:10.1111/ijd.12761Prospective histological study, six microneedling sessions at 2-week intervals with biopsies at baseline and at 1 and 3 months (Egypt); n = 10. Carries in this article: significant increases in collagen types I, III and VII and tropoelastin by the 3-month biopsy, and the authors’ note that multiple sessions are usually needed to maintain the improvement. Disclosure: none stated in the PubMed record.
- 14.Iizuka H. Epidermal turnover time. J Dermatol Sci. 1994;8(3):215-217. PMID 7865480. doi:10.1016/0923-1811(94)90057-4Short analytical paper recalculating epidermal turnover from published cell kinetic data. Carries in this article: the epidermis replaces itself over weeks, with the author calculating 47 to 48 days from Weinstein’s data in place of the 39 days often quoted. An older landmark, included in addition to the recent sources.
- 15.Weinstein GD, McCullough JL, Ross P. Cell proliferation in normal epidermis. J Invest Dermatol. 1984;82(6):623-628. PMID 6725985. doi:10.1111/1523-1747.ep12261462Tritiated thymidine kinetic study of normal human epidermis; labeled mitoses curve from 11 subjects. Carries in this article: the cell cycle of 311 hours and the three-compartment model of epidermal renewal on which later turnover estimates rest. An older landmark, included in addition to the recent sources.
- 16.Knauer G, Chang A, Gupta A, Brownstone N, Mejia N, Bauman S, et al. Clinical Evidence and Commercial Landscape of Topical Exosomes for Skin Rejuvenation: A Scoping Review. Aesthet Surg J. 2026;46(11):NP148-NP157. PMID 42411735. doi:10.1093/asj/sjag141Scoping review of 18 human studies of topical exosomes plus a market survey of 20 commercial cosmetic products. Carries in this article: ten studies paired exosomes with a delivery procedure and eight used topical application alone, and the commercial products carried minimal information on isolation, processing or shelf life, the reason one study’s timeline does not transfer to a different product. Disclosure: academic authors (USA); no conflict statement in the PubMed record.
- 17.U.S. Food and Drug Administration. Public Safety Notification on Exosome Products. December 6, 2019 (content current as of 12/06/2019; verified 4 November 2026). https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/public-safety-notification-exosome-productsAgency safety notification (CBER). Carries in this article: the statement that there are currently no FDA-approved exosome products, and that exosomes used to treat diseases and conditions in humans are regulated as drugs and biological products.
- 18.U.S. Food and Drug Administration. Microneedling Devices. Content current as of 10/15/2025; verified 4 November 2026. https://www.fda.gov/medical-devices/aesthetic-cosmetic-devices/microneedling-devicesAgency device information page (CDRH). Carries in this article: the FDA has authorized microneedling devices to improve the appearance of facial acne scars, facial wrinkles and abdominal scars in patients aged 22 or older, and the page states the devices are not approved for delivery of cosmetics, topical medications, drugs or blood products into the skin.
- 19.U.S. Food and Drug Administration. Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes. Issued July 22, 2020; content current as of 04/09/2024; verified 4 November 2026. https://www.fda.gov/vaccines-blood-biologics/consumers-biologics/consumer-alert-regenerative-medicine-products-including-stem-cells-and-exosomesAgency consumer alert (CBER). Carries in this article: the repeated statement that there are currently no FDA-approved exosome products, and that the only approved stem cell products are cord blood-derived hematopoietic progenitor cells for disorders of blood production.