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Stem Cell Therapy for Erectile Dysfunction

Stem cell therapy (SCT) for erectile dysfunction is an investigational regenerative approach intended to regenerate smooth muscle, endothelium and cavernous-nerve function. The AUA 2018 guideline classifies intracavernosal stem cell therapy as investigational .[1] The guideline panel found that the studies do not show that benefits reliably outweigh risks or burdens. Restoration of normal erectile function has not been convincingly demonstrated, and the best cell source, dose and duration of effect are not established. No stem cell product is currently FDA-approved for ED.[1][22]

AUA 2018, investigational only; commercial-clinic risk. "For men with ED, intracavernosal stem cell therapy should be considered investigational ."[1]

Counsel patients that SCT for ED should be pursued only within approved clinical trials. Unregulated clinics market stem-cell injections for ED without adequate evidence, which raises patient-safety and ethical concerns.[2]

Rationale and target populations​

Conventional ED treatments (PDE5i, ICI, VED) relieve symptoms but do not reverse the underlying pathology of smooth-muscle degeneration, endothelial dysfunction, cavernous-nerve injury and corporal fibrosis. SCT is intended to be restorative.[3][4]

The populations with the greatest unmet need and most active research are:[5][6]

  • Post-radical-prostatectomy ED (cavernous nerve injury)
  • Diabetic ED (vasculogenic and neuropathic)
  • PDE5i-refractory ED of any etiology

Cell sources​

Several cell sources have been investigated, each with different trade-offs[6][7]:

SourceNotes
Adipose-derived stem cells (ADSCs)Most commonly used in clinical trials; harvested via liposuction; abundant yield
Bone-marrow-derived MSCs (BMSCs)Studied in phase I trials; require bone-marrow aspiration
Bone-marrow mononuclear cells / concentrateMinimally manipulated; point-of-care processing
Umbilical-cord-blood MSCs (CBMSCs)Allogeneic, low immunogenicity; preclinical superior neurotrophic-factor secretion vs ADSCs[8]
Placenta-derived MSCsRecent clinical-trial data (Ji 2025)[9]
Urine-derived stem cells (UDSCs)Non-invasive harvest; preclinical only[6]
Dental pulp stem-cell conditioned medium (SHED-CM)Acellular; uses paracrine factors (Koga 2022)[10]

Mechanism — predominantly paracrine​

Preclinical ED models suggest that any therapeutic effect is largely paracrine rather than due to direct cellular differentiation[7][6][4]:

  1. Paracrine signaling. VEGF, BDNF, NGF, and IGF-1 secretion leading to angiogenesis, neuroregeneration, and smooth-muscle repair.
  2. Anti-fibrotic effects. Reduced collagen deposition; improved smooth-muscle-to-collagen ratio in corpora cavernosa.
  3. Anti-inflammatory and immunomodulatory effects. Reduced oxidative stress and inflammatory cytokines.
  4. Endothelial repair. Restoration of eNOS and nNOS expression; improved NO–cGMP signaling.
  5. Recruitment of endogenous progenitor cells. Host-driven repair.
  6. Extracellular vesicles (EVs or exosomes). Bioactive cargo (mRNA, miRNA, proteins) mediating tissue repair even without intact-cell transplantation.[7]

Routes of administration​

RouteNotes
Intracavernosal injection (ICI)The predominant route in clinical trials; direct delivery to the corpus cavernosum[11]
Intravenous (systemic)Used in Nguyen Thanh 2021 ADSC trial for sexual dysfunction[12]
TransendocardialSecondary ED outcomes from cardiac stem-cell trials (Ory 2020)[13]
Periprostatic / peri-neural with scaffoldPreclinical models loading scaffold-bound stem cells onto injured cavernous nerves[14]

Clinical trial evidence​

Published human data are limited, mainly phase I safety trials with small samples. A 2021 review identified 27 registered trials, nine with published results involving fewer than 100 patients.[15] A 2024 ESSM review included 19 studies and 421 patients with male sexual dysfunction, but only two studies followed patients beyond 12 months.[20] In a 2026 double-blind, placebo-controlled RCT, 70 men with ED after radical prostatectomy received one intracavernous injection of autologous ADRCs or placebo; between-group changes did not differ significantly for IIEF-5 at 12 months (p > 0.99), EHS at 6 months (p = 0.85), or RigiScan at 6 months, and no severe adverse events were observed.[23] The 2026 EAU guideline found conflicting results in four small placebo-controlled trials and insufficient evidence for a clinical recommendation.[21]

StudyCell typenPopulationRouteKey outcomesFollow-up
Hansen 2026 placebo RCT[23]Autologous ADRCs vs placebo70 (35 per arm)Post-RP EDICINo statistically significant between-group difference in IIEF-5 change at 12 mo (primary endpoint; p > 0.99), EHS at 6 mo (p = 0.85), or RigiScan at 6 mo; no severe adverse events12 mo
Haahr 2018[16]Autologous ADRCs21Post-RP EDICI53% (8/15) continent men achieved erections sufficient for intercourse; whole-cohort IIEF-5 median 6 to 8 at 12 mo; no improvement in the 6 incontinent men or in men with ED before RP12 mo
You 2021[5]Autologous BMSCs10 (9 completed)Post-RP (5) and DM (5) EDICIMean IIEF rose from 18.1 to 24.9 at 1 mo (p = 0.02), but did not differ significantly from baseline at 12 mo; no adverse event judged related to the cells[20]12 mo
Bieri 2020 (Caverstem)[17]Autologous BM concentrate140 (40 trial + 100 registry)PDE5i-refractoryICIMean IIEF-5 change +2/+3 in the 40-man phase I groups and +9 in the 100-man registry; no placebo comparison; peak at 3 mo, maintained at 6 mo; industry-fundedEfficacy and safety reported to 6 mo; longest individual follow-up 12 mo
Nguyen Thanh 2021[12]Autologous ADSCs31 (15 men, 16 women)Reduced sexual functionIVTestosterone rose and stayed high to 6 mo, then fell by 12 mo; satisfaction reported by all; no SAEs12 mo
Koga 2022 (acellular)[10]SHED-CM38Mixed EDICI97.4% improved; mean IIEF-5 13.1 to 19.3 after variable exposure (32/38 received three injections); 47.4% (18/38) reached IIEF-5 > 21; open-label, no controlNot stated
Ory 2020 post-hoc[13]Allogeneic / autologous MSCs / BM-MNCs36 (28 SCT, 8 placebo)Ischemic CMP + EDTransendocardialNo significant SCT–placebo difference; exploratory within-group IIEF-EF increases from 14 to 20 at 12 mo in the 200M-cell subgroup (p = 0.014) and autologous-source subgroup (p = 0.030)12 mo
Ji 2025 RCT[9]Placenta-derived MSCs, LI-ESWT, or both33 (three arms)Selected men with type 2 diabetic EDICI + ESWTIIEF-EF change was the stated primary endpoint; at 6 mo the authors reported mean scores of 19.8 (combination), 17.5 (cells alone), and 16.67 (LI-ESWT alone), with the combination higher than either monotherapy (p < 0.05). EHS > 2 occurred in 7/10, 5/11, and 4/10 evaluable patients, respectively; pairwise EHS superiority was not established. SEP-3 responses did not differ (p = 0.789)6 mo

Network meta-analysis — SCT vs other regenerative therapies​

Hinojosa-Gonzalez 2024 Bayesian network meta-analysis of 16 RCTs / 907 patients comparing SCT, PRP, and LI-ESWT[18]:

TherapySMD vs control95% CrISignificance
Stem cell therapy0.92−0.49 to 2.3Not significant (wide CrI; few RCTs; high heterogeneity)
PRP0.830.15 to 1.5Significant
LI-ESWT0.840.49 to 1.2Significant

The non-significant result for SCT is attributed to the small number of RCTs and high heterogeneity. Only PRP and LI-ESWT had credible intervals excluding zero. The authors note heterogeneity in control groups and follow-up durations.[18]

Safety​

Published clinical trials of SCT for ED report a favorable short-term safety profile:[5][11][16][17]

  • No serious adverse events were attributed to SCT.
  • Minor adverse events include bruising at the harvest or injection site, transient pyrexia, back pain after bone-marrow aspiration, and mild local pain.
  • No tumor formation or ectopic tissue growth has been reported in these small ED trials during available follow-up. In You et al., one diabetic participant had two serious hyperglycemia events, both judged unrelated to the cell therapy.[5] FDA has received reports of tumor formation and infections associated with unapproved regenerative products marketed for a range of conditions.[22]
  • Long-term safety beyond 12 months is not established.

Combination therapies — emerging signal​

Combining SCT with other regenerative modalities has been proposed to be synergistic[4][9]:

  • SCT and LI-ESWT. In the Ji 2025 RCT (33 randomized across three active arms), 7/10 evaluable patients in the combination arm reached EHS > 2 at six months versus 5/11 with cells alone and 4/10 with LI-ESWT alone. Pairwise EHS superiority was not established, and successful-intercourse responses (SEP-3) did not differ between arms (p = 0.789).[9]
  • SCT and PRP. Overlapping but complementary mechanisms; PRP provides concentrated growth factors that may enhance stem-cell survival and engraftment.[4]
  • SCT and hydrogen sulfide donors (NaHS). Preclinical synergistic improvement in cavernous-nerve-injury models (Asker 2025).[19]

Current barriers​

Barriers to SCT becoming standard of care[3][7][15]:

  1. Lack of large randomized placebo-controlled trials. Most published data are Phase I with small samples and short follow-up.
  2. Heterogeneity in cell source, dose, processing, delivery route, and outcome measures across studies.
  3. Optimal cell source undetermined. Head-to-head comparisons of cell types in humans are lacking.
  4. Optimal dosing and re-treatment interval unknown.
  5. Long-term durability and safety not established. In an uncontrolled eight-man diabetic ED cohort, mean IIEF-5 was 10.4 at baseline, 17.9 at six months, and 10.6 at 24 months (no significant difference from baseline at 24 months).[24]
  6. Cost-effectiveness unstudied.
  7. Commercial exploitation. Unregulated clinics market SCT for ED without adequate evidence.[2]

Guideline position​

BodyPosition
AUA 2018[1]Investigational ; use only within an IRB-approved clinical trial. The guideline also classes LI-ESWT as investigational and PRP as experimental
EAU 2026[21]Four small placebo-controlled SCT trials had conflicting findings; evidence is insufficient for a clinical recommendation.
ESSM 2024[20]Investigational; offer only in Ethics Committee-approved trials (Good Clinical Practice Statement). Counsel that ED effect sizes have uncertain clinical significance and supporting evidence is limited (Level 3, Grade C).

When to refer / when not to use​

  • Refer to a clinical trial. In the United States, refer interested patients only to an IRB-approved trial with appropriate FDA oversight (including an IND when required), and assess protocol eligibility; a ClinicalTrials.gov listing alone does not establish compliance.[1][22]
  • Do not offer outside trials: routine clinical use is not supported by the evidence; commercial-clinic SCT is not equivalent to trial-grade therapy and should be discouraged.[2]
  • LI-ESWT and PRP. Their pooled effects versus control were statistically significant in a network meta-analysis, whereas the SCT credible interval crossed zero; the authors questioned the clinical importance of the LI-ESWT and PRP effects.[18] AUA 2018 classes LI-ESWT as investigational and PRP as experimental ; EAU 2026 weakly recommends LI-ESWT for selected vasculogenic ED, confines PRP to clinical trials, and finds SCT evidence insufficient for a clinical recommendation.[1][21]

Postoperative / post-procedural management​

  • Post-injection care. Published cell-therapy protocols used different compression or tourniquet practices; post-SCT activity limits are not standardized, so follow the enrolled trial protocol.[9][17]
  • Concomitant ED medication. Some cell-therapy trials allowed PDE5 inhibitors or other ED medication, whereas others prohibited them; follow the enrolled protocol.[20]
  • PRO assessment. IIEF / IIEF-5 / EHS at baseline, 1 mo, 3 mo, 6 mo, 12 mo per the major trial protocols.
  • Counseling. Patients are told before treatment that SCT is investigational and not FDA-approved, and that long-term safety and durability are undefined.[1][20][22]

See Also​

References​

1. Burnett AL, Nehra A, Breau RH, et al. Erectile dysfunction: AUA guideline. J Urol. 2018;200(3):633–641. doi:10.1016/j.juro.2018.05.004

2. Israeli JM, Lokeshwar SD, Efimenko IV, Masterson TA, Ramasamy R. The potential of platelet-rich plasma injections and stem cell therapy for penile rejuvenation. Int J Impot Res. 2022;34(4):375–382. doi:10.1038/s41443-021-00482-z

3. Wang B, Gao W, Zheng MY, Lin G, Lue TF. Recent advances in stem cell therapy for erectile dysfunction: a narrative review. Expert Opin Biol Ther. 2023;23(6):565–573. doi:10.1080/14712598.2023.2203811

4. Towe M, Peta A, Saltzman RG, et al. The use of combination regenerative therapies for erectile dysfunction: rationale and current status. Int J Impot Res. 2022;34(8):735–738. doi:10.1038/s41443-021-00456-1

5. You D, Jang MJ, Song G, et al. Safety of autologous bone marrow-derived mesenchymal stem cells in erectile dysfunction: an open-label phase 1 clinical trial. Cytotherapy. 2021;23(10):931–938. doi:10.1016/j.jcyt.2021.06.001

6. Fu X, Sheikholeslami A, Zhanbyrbekuly U, et al. Advances in stem cell therapy for erectile dysfunction: preclinical evidence and emerging therapeutic approaches. Front Med. 2025;12:1519095. doi:10.3389/fmed.2025.1519095

7. Patel AA, Shafie A, Mohamed AH, et al. The promise of mesenchymal stromal/stem cells in erectile dysfunction treatment: a review of current insights and future directions. Stem Cell Res Ther. 2025;16(1):98. doi:10.1186/s13287-025-04221-9

8. Ti Y, Yang M, Chen X, et al. Comparison of the therapeutic effects of human umbilical cord blood-derived mesenchymal stem cells and adipose-derived stem cells on erectile dysfunction in a rat model of bilateral cavernous nerve injury. Front Bioeng Biotechnol. 2022;10:1019063. doi:10.3389/fbioe.2022.1019063

9. Ji YH, Zhang YF, Tan X, et al. High-activity placenta-derived mesenchymal stem cells combined with low-intensity extracorporeal shock wave therapy for diabetic erectile dysfunction: a prospective randomized controlled trial. Stem Cell Res Ther. 2025;16(1):359. doi:10.1186/s13287-025-04499-9

10. Koga S, Horiguchi Y. Efficacy of a cultured conditioned medium of exfoliated deciduous dental pulp stem cells in erectile dysfunction patients. J Cell Mol Med. 2022;26(1):195–201. doi:10.1111/jcmm.17072

11. Hansen ST, Lund M, Ostergaard LD, Lund L. Role of regenerative therapies on erectile dysfunction after radical prostatectomy. Int J Impot Res. 2021;33(4):488–496. doi:10.1038/s41443-020-00406-3

12. Nguyen Thanh L, Dam PTM, Nguyen HP, et al. Can autologous adipose-derived mesenchymal stem cell transplantation improve sexual function in people with sexual functional deficiency? Stem Cell Rev Rep. 2021;17(6):2153–2163. doi:10.1007/s12015-021-10196-w

13. Ory J, Saltzman RG, Blachman-Braun R, et al. The effect of transendocardial stem cell injection on erectile function in men with cardiomyopathy: results from the TRIDENT, POSEIDON, and TAC-HFT trials. J Sex Med. 2020;17(4):695–701. doi:10.1016/j.jsxm.2020.01.003

14. Hu D, Liu C, Ge Y, et al. Poly-L-lactic acid/gelatin electrospun membrane-loaded bone marrow-derived mesenchymal stem cells attenuate erectile dysfunction caused by cavernous nerve injury. Int J Biol Macromol. 2024;265(Pt 2):131099. doi:10.1016/j.ijbiomac.2024.131099

15. He M, von Schwarz ER. Stem-cell therapy for erectile dysfunction: a review of clinical outcomes. Int J Impot Res. 2021;33(3):271–277. doi:10.1038/s41443-020-0279-8

16. Haahr MK, Harken Jensen C, Toyserkani NM, et al. A 12-month follow-up after a single intracavernous injection of autologous adipose-derived regenerative cells in patients with erectile dysfunction following radical prostatectomy: an open-label phase I clinical trial. Urology. 2018;121:203.e6–203.e13. doi:10.1016/j.urology.2018.06.018

17. Bieri M, Said E, Antonini G, et al. Phase I and registry study of autologous bone marrow concentrate evaluated in PDE5 inhibitor refractory erectile dysfunction. J Transl Med. 2020;18(1):24. doi:10.1186/s12967-019-02195-w

18. Hinojosa-Gonzalez DE, Saffati G, Orozco Rendon D, et al. Regenerative therapies for erectile dysfunction: a systematic review, Bayesian network meta-analysis, and meta-regression. J Sex Med. 2024;21(12):1152–1158. doi:10.1093/jsxmed/qdae131

19. Asker H, Sezen SF, Yilmaz-Oral D, et al. The beneficial effects of adipose-derived stem cell and hydrogen sulfide donor sodium hydrogen sulfide combination therapy on erectile dysfunction in a rat model of radical prostatectomy. Eur J Pharmacol. 2025;1001:177760. doi:10.1016/j.ejphar.2025.177760

20. Manfredi C, Boeri L, Sokolakis I, et al. "Cell therapy for male sexual dysfunctions: systematic review and position statements from the European Society for Sexual Medicine." Sex Med. 2024;12(1):qfad071. doi:10.1093/sexmed/qfad071

21. European Association of Urology. "EAU Guidelines on Sexual and Reproductive Health: Management of Erectile Dysfunction," section 5.6.8.a.3. 2026. Guideline

22. U.S. Food and Drug Administration. "Important Patient and Consumer Information About Regenerative Medicine Therapies." June 3, 2021. FDA

23. Hansen ST, Andersen DC, Jensen CH, Damkier P, Sørensen JA, Lund L. "A Randomized Double-blind, Placebo-controlled Trial of Adipose-derived Regenerative Cells Injected into Corpora Cavernosum Following Radical Prostatectomy." Eur Urol Focus. 2026;12(3):426-435. doi:10.1016/j.euf.2026.02.002

24. Al Demour S, Adwan S, Jafar H, Alhawari H, Awidi A. "Stem cell therapy in diabetic men with erectile dysfunction: a 24-month follow-up of safety and efficacy of two intracavernous autologous bone marrow derived mesenchymal stem cells injections, an open label phase 2 clinical trial." Basic Clin Androl. 2024;34:13. doi:10.1186/s12610-024-00229-y