Stem cells are present in several tissues throughout the human body, including bone marrow, blood, adipose tissue, dental pulp, and perinatal tissues such as umbilical cord blood and placenta. The type and properties of these cells vary substantially depending on their tissue of origin.
Did you know that in bone marrow alone, humans can have between 50,000 and 200,000 stem cells?
The use and understanding of stem cells is one of the most promising medical advancements of our time because they might be able to help treat life-threatening or chronic diseases.
But where are stem cells found? Let’s find out.
What Are Stem Cells?
Before we dive in and learn about what parts of the human body contain stem cells, let’s explore why they’re important.
Stem cells have the unique ability to create “daughter cells.” These cells either become more stem cells or turn into blood cells, brain cells, heart, or bone cells.
There are four broad types of stem cells.
- Embryonic Stem Cells (ESCs): Embryonic stem cells are collected during in-vitro fertilization procedures and can become any of the 200 cell types that form a human being. They are extremely versatile stem cells that have not been exposed to environmental factors like toxins.
- Perinatal Stem Cells: Perinatal stem cells are stem cells present during the perinatal period of human development. Common types include the stem cells present within the umbilical cord blood and tissue, the placenta, and the amniotic fluid.
- Adult Stem Cells: Adult stem cells are undifferentiated cells that are present in the body after development. Among the adult stem cell types, mesenchymal stem cells and hematopoietic stem cells are the most commonly sourced and utilized.
- Induced Pluripotent Stem Cells (iPS cells): To create iPS cells, scientists use mature cells (commonly, skin or blood cells) and reverse engineer them in a lab to mimic how embryonic stem cells behave. Like embryonic stem cells, iPS cells can become any of the cells that form a complete human being.
Where Are Stem Cells Found?
While stem cells are distributed throughout the human body, they are most prevalent within specific tissues, which we’ll discuss below.
First, let’s differentiate between two leading types of adult stem cells.
- Mesenchymal Stem Cells (MSCs) have a powerful ability to exert positive effects on other nearby cells. This phenomenon is known as “paracrine signaling.” When they differentiate into other cells, they prefer to become cells of the human structural system, such as muscles, tendons, ligaments, and fat.
- Hematopoietic Stem Cells (HSCs) prefer to differentiate into cells of the blood and immune system. These cells are commonly used in bone marrow transplants to help cancer patients regenerate their immune system after chemotherapy.
Bone Marrow
Both hematopoietic stem cells (HSC) and mesenchymal stem cells (MSCs) are present in human bone marrow. This springy tissue is important for immunity, disease prevention, and stem cell development.
Since both HSCs and MSCs are located in bone marrow, multiple types of cells can be created.
New blood cells are produced within the bone marrow and contain many types of cells that support immunity. More research is needed in this area so that we can fully utilize this stem cell resource for disease prevention and treatment.
Dental Pulp
You might be wondering, where are stem cells located in my teeth? This inner part of the tooth contains mesenchymal stem cells. Teeth have three layers and the innermost layer that contains blood vessels and nerves is also home to stem cells.
It is possible to harvest these cells, which shows great promise for human health.
Umbilical Cord Blood and Tissue
MSCs and cells similar to MSCs are also present in umbilical cord tissue. Retrieving these cells is non-invasive because it can happen during the delivery of a baby. Unlike bone marrow harvesting, it doesn’t cause any pain to the patient.
HSCs are specifically located in the blood of a newborn’s umbilical cord. These cells get collected and used in the treatment of blood-related cancers. If you’re giving birth, you can choose to collect cord blood and have it frozen for your own personal use or donate it.
The stem cells found in cord blood and tissues are a direct match to the baby and often a match for other family members as well.
Stem cells have even been found in the amniotic fluid that surrounds the baby while in the womb. With so many easily accessible ways to gather stem cells during and after pregnancy, perinatal tissues represent a promising source of stem cells for use in regenerative medicine.
Adipose (Fat) Tissue
MSCs are also located in adipose, or fatty tissues. These specific cells offer new insights into how stem cells can be used for regenerative therapies.
For simplicity, the mesenchymal cells present within adipose tissue are sometimes termed adipose-derived stem cells.
However, especially with adipose stem cells, the claims about their benefits often exceed what is verified. If you’re interested in stem cell therapies be sure you have vetted the medical facility and read current science.
Placental Tissue
The placenta is what keeps babies healthy during pregnancy. It brings all the nutrients, blood and oxygen from the mother to the baby. We already know that there are stem cells in the umbilical cord, but did you also know they’re in the placentas themselves?
Placentas are delivered during labor and therefore require little additional effort to harvest stem cells.
Placental tissue contains several populations of stem and stromal cells, including mesenchymal stromal cells of both fetal and maternal origin. While the placenta is often discarded as medical waste after delivery, it represents a readily accessible source of cells for research and potential therapeutic applications.
What Are Stem Cells Used For?
New studies emerge all the time to find unique uses for stem cells. To use them, stem cells have to be administered to a patient.
In cancer treatment, for example, chemotherapy kills even healthy cells. For this reason, chemo patients receive bone marrow transplants, which contain valuable MSCs and HSCs. These stem cells help to revitalize a patient’s immune system and revive essential functions for the body.
Since stem cells have the potential to support tissue repair, restoration, and regeneration, there is significant interest in their possible applications for people who are dealing with disease or injury.
Within the U.S., the Food and Drug Administration (FDA) regulates stem cell products and approved products are limited to specific indications. In December 2024, the FDA approved Ryoncil, the first mesenchymal stromal cell (MSC) therapy, for steroid-refractory acute graft-versus-host disease (aGVHD) in pediatric patients.
Ryoncil (remestemcel-L) was the first MSC product approved by U.S. FDA for any indication, making it an exciting world-first.
While this approval was historic, the Food and Drug Administration (FDA) is clear on its website that there can be significant consequences to seeking stem cell treatments that are not FDA approved. Even if the cells come from your own body, that doesn’t necessarily mean they will be an effective or safe treatment.
The Future of Stem Cells
Stem cell research continues to receive substantial investment from the National Institutes of Health (NIH), while scientists are increasingly moving stem cell discoveries from the laboratory into clinical trials.
In fiscal year 2025, the NIH reported approximately $2.59 billion in funding for Stem Cell and Progenitor Cell Research. The NIH also began reporting several more specific stem cell research categories in 2025, including $1.39 billion for Adult/Somatic Stem Cell and Progenitor Cell Research and $358 million for Human Embryonic Stem Cell Research. These figures reflect NIH research spending across grants, contracts, intramural projects, and other funding mechanisms.
The clinical landscape is also evolving. The FDA’s 2024 approval of Ryoncil was a historic milestone for mesenchymal stromal cell therapies and numerous cell therapy companies are continuing to advance other stem cell-based approaches through clinical development.
Meanwhile, researchers are advancing pluripotent stem cell-derived therapies for conditions that have historically been difficult to treat. For example, clinical studies are investigating stem cell-derived therapies for diseases such as Parkinson’s disease and Huntington’s disease. At the 2026 Annual Meeting of the International Society for Stem Cell Research (ISSCR), researchers presented new clinical data from a Phase 1/2 trial of pluripotent stem cell-derived dopaminergic progenitor cells for Parkinson’s disease, while another 2026 presentation highlighted the launch of a Phase 1b/2a trial of a pluripotent stem cell-derived neural stem cell therapy for Huntington’s disease.
These developments illustrate an important shift in the field. Stem cells are no longer solely a subject of basic laboratory research; certain stem cell-based products are now approved therapies, while many other approaches remain in clinical development. At the same time, the International Society for Stem Cell Research emphasizes that promising laboratory findings and early clinical trials should not be confused with established medical treatments. New stem cell interventions should demonstrate safety and effectiveness through appropriately designed clinical trials and regulatory review before becoming part of routine clinical care.
So, where are stem cells found? They are found in a wide range of tissues, including bone marrow, blood, adipose tissue, dental pulp, placenta, and umbilical cord blood and tissue. Researchers continue to investigate these cells, as well as embryonic stem cells and induced pluripotent stem cells, for their potential applications in regenerative medicine.
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