Stem Cell Secretome Therapy: What It Is, How It Is Studied, and What to Know About Safety

Stem cell secretome therapy is a cell-free approach based on substances released by mesenchymal stem cells (MSCs). These substances can be collected and processed separately from the stem cells themselves.

Research on secretome-based products is still ongoing. Studies are looking at their role in inflammation, immune regulation, and tissue repair. This article explains what the secretome is, what current research shows, how secretome and exosome-based products differ, and what shapes their composition and activity.

What Is Stem Cell Secretome?

MSCs are multipotent stromal cells found in tissues such as bone marrow, adipose tissue, placenta, and umbilical-cord-associated tissues. They are widely studied in regenerative medicine because of their ability to release biologically active signalling molecules.

MSCs communicate with surrounding cells by releasing proteins, growth factors, cytokines, lipids, nucleic acids, and extracellular vesicles. These substances, collectively known as the secretome, can be collected and studied as a cell-free therapeutic approach.

How Is Secretome Different From Stem Cell Therapy?

In stem cell therapy, patients receive living MSCs. In addition to releasing a secretome—including soluble factors and extracellular vesicles such as exosomes—MSCs may interact directly with surrounding immune and tissue cells. When the cells remain viable after administration, they usually continue to release signalling molecules over a period of time.

In secretome therapy, cell-derived substances are administered directly without the cells themselves. These products can deliver biological signals promptly, but they do not provide a living source that continues to produce new signals after administration. That’s why, in some cases, secretome or its individual components are used together with MSCs to potentially enhance their effects.

Why Are Cell-Free Approaches Being Studied?

Researchers are studying cell-free approaches because many of the effects associated with MSCs may be mediated by the signaling molecules they release, rather than by the long-term presence of the cells themselves. Using these molecules could make treatment products easier to prepare, standardize, store, and deliver than living-cell therapies.

Cell-free products may also avoid some challenges linked to living cells, such as uncertain survival and distribution after administration. This can make them safer in some settings. Their safety and effectiveness can still vary depending on the product composition, preparation method, dose, and route of administration.

What Does the Secretome Contain?

As mentioned above, the secretome is not a single substance. Its components can be grouped into several main categories.

Soluble Proteins, Growth Factors, and Cytokines

Some components of the secretome are soluble, meaning they are released directly into the surrounding fluid rather than enclosed in vesicles. These include:

• growth factors, which influence cell survival, proliferation, migration, and blood-vessel-related pathways;
• cytokines and chemokines, which help coordinate inflammatory and immune responses;
• enzymes and extracellular-matrix-related proteins, which affect how cells interact with their local environment.

Extracellular Vesicles, Including Exosomes

Extracellular vesicles (EVs) are another major component of the secretome. They are small particles surrounded by a lipid membrane and can carry proteins, lipids, messenger RNA, microRNA, and other biological molecules. Their lipid membrane protects this cargo as the vesicles move through the surrounding environment.

Exosomes are one type of extracellular vesicle. They are often discussed separately because they are among the most widely studied EVs in regenerative medicine. 

Other Signaling Components Released by Cells

The secretome can also contain:

• lipids and lipid mediators;
• metabolites;
• free nucleic acids;
• matrix-associated molecules;
• other extracellular particles.

Researchers are also investigating how these components may contribute to the potential biological effects of stem-cell-derived secretome therapy.

Is Secretome the Same as Exosomes?

The secretome is not the same as exosomes. The secretome is the broader mixture of substances released by MSCs, while exosomes are just one type of extracellular vesicle within it.

What makes exosomes distinct is how they are formed and identified. Researchers classify them using features such as their origin, size, composition, and molecular markers. 

How Might Secretome and Exosomes Influence Biological Processes?

Scientists are studying how secretome, mesenchymal stem cell, and exosome treatments may influence several overlapping biological mechanisms.

Cell Signaling and Tissue-Repair Pathways

Many secretome components act through paracrine signaling. This is a form of cell communication in which one cell releases biological molecules that act on nearby cells.

Through this mechanism, secretome components may be involved in:

• cell survival and migration;
• formation of new blood vessels;
• communication between immune and tissue cells;
• regulation of inflammatory responses.

Together, these signals may create a more supportive environment for tissue recovery by helping cells communicate, respond to stress, and regulate inflammation.

Modulation of Inflammatory Processes

Secretome components are also involved in inflammatory and immune pathways. Researchers have observed changes in cytokine signaling, macrophage activity, and the behavior of other immune cells.

These findings suggest that the secretome may modulate immune and inflammatory activity—by changing the strength and duration of the response rather than switching it off completely. 

Intercellular Communication Through Extracellular Vesicles

Extracellular vesicles such as exosomes can interact with recipient cells through several mechanisms:

• Receptor binding. Molecules on the vesicle surface can interact with receptors on the target cell.
• Endocytosis. The cell can take up the vesicle and bring it inside.
• Membrane fusion. In some cases, the vesicle membrane can merge with the cell membrane.
• Cargo release. Once inside, the vesicle can release its contents into the cell.
• Cellular response. This cargo may then take part in signaling pathways, gene regulation, and other cellular processes.

These mechanisms help understand why stem-cell-derived exosome therapy is being actively studied in regenerative medicine.

What Conditions Are Secretome, Exosome, and Stem Cell Therapies Being Studied For?

Results are already emerging for secretome, exosome, and stem cell therapies, and the clinical evidence will likely continue to grow. However, the data are still limited to predict outcomes or promise a specific result, and more studies are required.

Alongside published research, clinical experience with secretome- and exosome-based therapies is also growing. At Swiss Medica, a regenerative medicine clinic in Belgrade, Serbia, these approaches may be considered for patients with multiple sclerosis, Parkinson’s disease, autism, and other complex chronic conditions.

They are not offered to every patient. Before any treatment is considered, doctors review the patient’s medical history, previous treatments, current symptoms, and available test results.

Get a free online consultation

Book a free online consultation with our regenerative medicine doctors to find out whether secretome therapy may be suitable for your condition and treatment goals.

Dr. Aleksandra Fetyukhina, MD

Medical Advisor, Swiss Medica doctor

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Why Secretome Quality Is Not Just About “More Exosomes”: Inside the Preparation Process

The particle count shown on a product label can sound impressive:

1 billion particles.
10 billion particles.
100 billion particles.

But particle count alone says little about the quality of secretome or exosome therapy. What matters is where the cells come from, how they are cultured, how the material is isolated and purified, and how the final product is tested, stored, and used. 

At Swiss Medica, we carry out these stages in our own GMP-standard laboratory.

Step 1. Harvesting the Source Cells

The process begins with the cells that will produce the secretome. At Swiss Medica, these may include MSCs as well as other cell types, such as macrophages, depending on the treatment protocol. There are a few different types of cell sources:

• Donor MSCs may be obtained from placental or umbilical cord tissue. 
• Autologous cells may come from bone marrow, adipose tissue, or gingiva.

Different cell types produce different sets of signaling molecules, so the source influences the final secretome composition.

Step 2. Cell Culture and Isolation

After collection, the needed cells are separated from the surrounding tissue and prepared for culture. They are then grown in specialized media until the required quantity is reached.

As the cells grow, they release cytokines, growth factors, microRNAs, extracellular vesicles, including microvesicles and exosomes, and other signaling components. This mixture forms the secretome.

The released material is then collected and separated from the cells and other components of the culture medium.

Step 3. Safety and Quality-Control Testing

Before use, both exosome and secretome preparations are tested in our laboratory for size, concentration, exosome-associated markers, and sterility.

They are also checked for bacterial, fungal, and viral contamination. This helps confirm that the preparation meets the required quality and safety criteria before it is used in secretome, mesenchymal stem cell, or exosome treatments.

Step 4. Preservation

After testing, exosome and secretome preparations are cryopreserved at very low temperatures to maintain their stability until use.

Before administration, the required dose is thawed and prepared in sterile vials or syringes according to the planned treatment protocol.

Why Standardization Remains a Challenge

There are established laboratory standards and recommendations for how cell-derived products should be produced, characterized, stored, and tested. However, secretome products can still differ between laboratories because the source cells, culture conditions, isolation methods, and final composition are not always the same.

Treatment protocols may also be adapted to the patient and condition. This makes it important to understand how a clinic follows recognized quality standards while controlling its own production process.

Possible Risks and Side Effects of Secretome or Exosome Procedures—and How Swiss Medica Addresses Them

Human studies suggest that secretome, mesenchymal stem cell, and exosome treatments are generally well tolerated. A 2024 systematic review of 21 human studies found a low rate of serious adverse events, while also noting differences between products and study protocols.

At Swiss Medica, we usually see only short-term reactions, such as mild fever, fatigue, headache, or temporary discomfort at the administration site. Serious treatment-related reactions have not been typical in our clinical experience.

Before treatment, our doctors also review the patient’s diagnosis, medical history, medications, and possible contraindications. This helps reduce avoidable risks and choose the most appropriate route and dose for each case.

Key Takeaways About Stem Cell Secretome and Exosomes

These are the main points to keep in mind when considering a secretome stem cell therapy:

• Secretome is a broad mixture of substances released by cells.
• Exosomes are only one component within the wider group of extracellular vesicles that may be present in secretome preparations.
• MSC therapy and stem cell-derived secretome use different biological products: living stem cells in one case and cell-derived substances in the other. They can also be used in combination in selected cases.
• The composition of the secretome can vary depending on the cell source, culture conditions, isolation method, storage, and dose.
• A higher particle count does not automatically mean a better or more active product.
• Many of the potential advantages of stem-cell-derived exosome therapy are still being investigated clinically.
• Early clinical research is demonstrating promising results for a variety of conditions, including musculoskeletal, skin, neurological, and respiratory disorders.

Discuss Your Options With a Regenerative Medicine Specialist

At Swiss Medica, we use personalized regenerative medicine protocols based on recognized medical and laboratory standards. Since 2011, we have treated more than 10,000 patients with different conditions. This experience helps us adapt each program to the individual patient while keeping the treatment process structured and medically supervised.

We also provide a clear estimate for the full treatment program before the patient travels. The quoted stem cell therapy cost is not limited to cell or exosome injections. Depending on the program, it usually includes:

• additional medical procedures and supportive therapies;
• accommodation at our hospital;
• meals;
• medical monitoring during the stay;
• interpreter support if needed;
• airport transfers.

The goal is to provide a full hospital experience, with treatment, daily support, and monitoring organized in one place rather than leaving the patient to arrange each part separately.

Contact us

To find out whether secretome therapy may be suitable for you, book a free online consultation with our doctors. They will review your diagnosis, medical history, previous treatments, and goals and explain which options may be appropriate in your case.

Dr. Aleksandra Fetyukhina, MD

Medical Advisor, Swiss Medica doctor

Your Name Please fill out this field Phone Please fill out this field E-mail Please fill out this field

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