PRP and Stem Cell Therapies for Nonobstructive Azoospermia: What the Latest Research Shows

For men facing nonobstructive azoospermia (NOA)—a condition where no sperm are present in the ejaculate due to impaired sperm production—the path to biological fatherhood can feel impossibly narrow. When traditional treatments like microsurgical testicular sperm extraction (micro-TESE) fail to retrieve viable sperm, many patients are left wondering if any options remain.

At the Stem Cell & PRP Institute of L.A., Dr. Padra Nourparvar stays at the forefront of regenerative medicine research, including emerging therapies that may offer hope to men with difficult-to-treat male factor infertility. While PRP and stem cell therapies for NOA remain investigational with no established clinical protocols or regulatory approval for routine use, the scientific community is actively investigating these approaches with encouraging early results.

Here’s what the current evidence tells us about these emerging regenerative options for male infertility.

Understanding Nonobstructive Azoospermia

NOA affects approximately 1% of all men and accounts for roughly 10% of male infertility cases. Unlike obstructive azoospermia, where sperm production is normal but blocked from reaching the ejaculate, NOA involves a fundamental disruption in spermatogenesis—the process by which sperm cells are produced in the testes.

Causes of NOA include genetic abnormalities, hormonal imbalances, prior chemotherapy or radiation, cryptorchidism (undescended testicles), and idiopathic factors where no clear cause can be identified. The gold-standard treatment—micro-TESE—can successfully retrieve sperm in approximately 40-60% of cases, but for men who fail sperm retrieval, options have historically been limited to donor sperm or adoption.

This is precisely why the regenerative medicine community has turned its attention to biologics that might restore or enhance testicular function.

Intratesticular PRP Injection: The Science Behind the Promise

Platelet-rich plasma (PRP) therapy concentrates growth factors from a patient’s own blood, creating a biologic solution that has shown tissue-reparative and regenerative properties across multiple medical specialties. Researchers have hypothesized that when injected directly into testicular tissue, PRP’s concentrated growth factors might support spermatogenesis through antioxidative mechanisms and tissue repair.

A comprehensive 2025 narrative review published in Fertility and Sterility examined the current evidence for intratesticular autologous PRP injection in couples with NOA. The review concluded that autologous PRP therapy shows promise for NOA, particularly for patients who have failed prior micro-TESE attempts. However, the authors emphasized that randomized controlled trials are essential before these findings can be translated into clinical practice. Read the full study →

Another 2025 publication in Stem Cell Research & Therapy explored PRP’s potential role in male fertility more broadly, positioning it as a path forward for personalized and regenerative therapies. The research highlighted PRP’s growth factor content and its potential to modulate the testicular microenvironment. Read the full study →

What Animal Studies Tell Us

While human data remains limited, animal studies have provided encouraging mechanistic insights into how PRP might support testicular function.

Research using chemotherapy-induced NOA models in rats demonstrated that intratesticular PRP injection can improve testicular size and weight, modulate spermatogenesis-related gene expression, and ameliorate oxidative stress markers. These findings suggest that PRP may help create a more favorable environment for sperm cell development, even in tissue damaged by toxic exposures. Read the full study →

However, translating animal results to human clinical outcomes requires caution. Optimal dosing, injection protocols, and timing relative to repeat sperm retrieval attempts have not been established in large-scale human trials.

Mesenchymal Stem Cell Therapy: Restoring Spermatogenesis

Mesenchymal stem cells (MSCs) represent another regenerative approach under investigation for NOA. These multipotent cells can differentiate into various cell types and secrete paracrine factors that may support tissue regeneration and reduce inflammation.

A landmark 2025 systematic review published in the Journal of Investigative Medicine analyzed 39 preclinical studies examining MSC transplantation into the testis. The results were striking: 37 of 39 studies demonstrated restoration of spermatogenesis following MSC treatment. Improvements were documented in germ cell differentiation, sperm parameters, hormonal levels, and fertility-related markers. Read the full study →

An earlier 2021 systematic review in Stem Cell Research & Therapy examined both mesenchymal stromal/stem cells and their exosomes for restoration of spermatogenesis in NOA, establishing the foundation for ongoing research in this field. Read the full study →

Exosomes: The Next Frontier

Exosomes—tiny vesicles secreted by stem cells that carry proteins, lipids, and genetic material—are emerging as a particularly promising therapeutic approach. These cell-derived particles can deliver regenerative signals without the complexity of transplanting whole cells.

A 2024 study published in Reproduction compared MSC-derived exosomes with PRP in a rat model of NOA. The research found that exosomes may be more effective than PRP alone in restoring spermatogenesis, suggesting that combining these approaches or using exosome therapy independently could offer enhanced therapeutic potential. Read the full study →

Research continues to explore how exosome therapy alters gene expression in testicular tissue. A 2020 study in Gene demonstrated that MSC treatment in busulfan-induced azoospermic rats altered the expression of certain microRNAs and their target genes, providing molecular evidence for how these therapies might work at the cellular level. Read the full study →

The Broader Landscape of Male Fertility Research

A comprehensive 2021 review in The Lancet examined male infertility globally, highlighting the need for innovative treatments. Read the full study → A 2025 article in Fertility and Sterility explored stem cell-based therapies from testicular stem cells to in vitro gametogenesis. Read the full study →

Current AUA/ASRM guidelines provide the standard framework for managing NOA, though these continue to evolve. Read the 2024 guideline update → The ASRM’s 2018 committee opinion on NOA management remains a foundational document. Read the committee opinion →

Important Considerations for Patients

These therapies remain investigational. Neither intratesticular PRP nor stem cell therapy for NOA has received FDA approval. Any treatment would be part of a research or investigational protocol.

Individual results vary significantly. The underlying cause of NOA, duration of infertility, age, and testicular health all influence outcomes. Animal model results may not translate directly to human success.

Timing matters. Optimal timing relative to repeat sperm retrieval attempts remains under investigation. Coordination between regenerative medicine specialists and reproductive endocrinologists is essential.

Comprehensive evaluation is essential. Patients should undergo complete evaluation to rule out treatable causes and establish realistic expectations.

Why Regenerative Medicine Offers Hope

Despite the investigational nature of these therapies, the scientific trajectory is encouraging. The consistency of positive results across preclinical studies, the biological plausibility of regenerative mechanisms, and the urgent unmet need for patients who have failed conventional treatment all support continued research investment in this area.

At the Stem Cell & PRP Institute of L.A., Dr. Padra Nourparvar brings training from UCLA, UC Irvine, NYU, CHLA, and Mount Sinai to the evaluation and treatment of complex conditions. Our practice follows strict FDA guidance, uses sterile technique, and maintains a secure clinical database tracking outcomes—essential practices when working with emerging therapies.

Schedule a Consultation

If you or your partner are facing nonobstructive azoospermia and are interested in learning more about investigational regenerative approaches, we invite you to schedule a consultation with Dr. Padra Nourparvar at the Stem Cell & PRP Institute of L.A. in Beverly Hills.

During your consultation, we can review your complete medical history, discuss the current state of research, and help you understand whether participation in investigational protocols might be appropriate for your situation.

Important Disclosure: Our clinic does not offer stem cells or stem cell therapy as a cure for any condition, disease, or injury. No statements or implied treatments have been evaluated or approved by the FDA. Treatments are considered investigational, and results may vary. A consultation with our board-certified physician is required before starting any treatment to confirm whether a procedure would be appropriate for you.