Erectile dysfunction (ED), or the inability to get and maintain an erection long enough for satisfying sexual activity, affects many men. It can be due to various causes such as nerve damage or vascular issues, which can lead to inflammation, formation of fibrous tissue in the penis, venous leak, and the eventual loss of erectile function.

Current treatments for ED focus on symptoms rather than the root cause. However, scientists in the field are curious about the potential of regenerative therapies, including stem cell therapy, to treat ED. Stem cells are versatile cells in the body capable of forming different tissues and can be sourced from bone marrow, fat, or other tissues. As such, stem cell therapy shows promise for ED treatment by promoting tissue regeneration, reducing inflammation, and improving blood flow to the penis.

Early studies suggest stem cell injections can restore natural tissue structure and function in animal models. Nevertheless, it is important to assess the safety and effectiveness of stem cell therapy in treating ED in humans, and clinical trials are currently underway to do just that.

Recently, a team of researchers conducted a thorough search of medical databases for studies on the use of stem cell therapy for ED, spanning from inception until March 2023. They included only clinical trials involving humans and excluded animal studies or those using derivatives of stem cells.

Two reviewers screened abstracts and full texts, selecting relevant studies following specific criteria. Data on study design, type and source of stem cells, dosage, outcomes, and adverse effects were collected and documented. The researchers then analyzed the studies and summarized their findings, anticipating differences in study designs and outcomes. They also investigated potential biases in the research.

In the end, the systematic review identified 18 clinical trials assessing the effects of stem cell therapy on ED. These trials involved various types of stem cells, including adipose-derived stem cells (cells found in fat tissue), bone marrow-derived stem cells, umbilical cord-derived stem cells, placental matrix-derived stem cells, and stem cells from human exfoliated deciduous dental pulp (cells found in baby teeth that have fallen out naturally).

The studies showed promising results in improving erectile function, with significant increases in International Index of Erectile Function (IIEF) scores and Erection Hardness Scores (EHS) observed after stem cell therapy. Most trials reported safety and tolerability of stem cell therapy, with some demonstrating sustained improvements in erectile function up to 12 months post-treatment. Still, while these therapies have shown potential benefits in improving erectile function in these trials, further research is needed to validate these findings.

The authors of the present study concluded that while injecting stem cells into the penis may help restore damaged tissue, the exact method of how this potential treatment works remains unclear. Studies in animals and some small human trials have shown promising results, especially with adipose-derived stem cells, bone marrow-derived stem cells, and umbilical cord-derived stem cells. Nonetheless, some studies did not show consistent effects, and the way data were presented across the studies varied, making comparisons difficult. So, while stem cell therapy appears safe with mostly mild side effects, future research on larger, controlled trials can help us better understand stem cell therapy’s effectiveness and standardize treatment methods.

References:

• Furtado, T. P., Saffati, G., Furtado, M. H., & Khera, M. (2024). Stem cell therapy for erectile dysfunction: A systematic review. Sexual Medicine Reviews, 12(1), 87–93. https://doi.org/10.1093/sxmrev/qead040