You may have heard that stem cells are the body’s “master cells” that can become different types of cells. While this is true in certain contexts, a lesser-known—and often more important—feature of the stem cells used in therapy is their ability to seek out areas of inflammation or damage and send signals that activate the body’s own healing processes, calming the immune system and promoting repair.

When given intravenously, these stem cells travel through the bloodstream and, within the first 24 to 48 hours, release a blend of signaling molecules—including growth factors and exosomes—that instruct your body’s cells to reduce inflammation, support tissue repair, and modulate immune responses. Although the stem cells themselves are cleared from the body within a few days, the healing processes they trigger can continue for weeks or even months.

Not all stem cells are the same—and when people talk about stem cell therapy for healing, inflammation, joint pain, or immune-related conditions, they’re almost always referring to mesenchymal stem cells (often shortened to MSCs). MSCs are a specific type of adult stem cell found in places like bone marrow, fat tissue, and umbilical cord tissue. Unlike embryonic stem cells, MSCs don’t form new organs or tissues when given intravenously. Instead, their main job is to modulate the immune system, reduce inflammation, and support healing—exactly the effects used in regenerative medicine.

So while we often just say “stem cells” for simplicity, “mesenchymal” is the important detail that tells you what kind of stem cell is being used—and why it’s considered appropriate for this type of therapy.

Exosomes are a key part of the blend of healing signals released by stem cells. These are tiny “biological bubbles” (technically called “extracellular vesicles”) packed with molecules such as proteins or RNA that carry biological instructions. Cells send these exosomes out to communicate with other cells in the body. When a recipient cell absorbs an exosome, it reads and carries out the contained instructions. The exosomes from stem cells instruct cells to shift into healing mode: reducing inflammation, repairing tissue, or calming an overactive immune response. In exosome therapy, these natural messengers are collected and delivered intravenously to help jump-start the body’s own repair systems—without using live cells.

Both therapies support healing by delivering natural biological signals—but they do so in fundamentally different ways. Stem cell therapy uses live mesenchymal stem cells. These are active, intelligent responders, sensing the local environment—detecting levels of inflammation, tissue damage, or immune imbalance—and dynamically adjust the mix of signals they release, responding in real time. Exosome therapy, by contrast, delivers only the pre-made signaling packages—the exosomes—that were collected from stem cells grown in the lab. Because they’re produced before they ever encounter your body, they can’t adapt to your unique condition—they deliver the same set of instructions regardless of what your tissues actually need at the time. Both can promote lasting repair, but only live stem cells have the ability to sense and intelligently react to your body’s current state.