Where Do Stem Cells Come From? Sources, Locations and Potency

Where do stem cells come from? Stem cells come from four places: early embryos a few days after fertilization, tissues of the adult body such as bone marrow and fat, birth tissues such as umbilical cord blood, and the laboratory, where scientists can reprogram ordinary adult cells into stem cells (Cleveland Clinic). Where a cell comes from largely decides its potency, meaning how many cell types it can become, and that in turn decides how it can be used.

This page explains where stem cells live in the body, how researchers and doctors obtain them, and what terms like multipotent and pluripotent mean. For an overview of each family of cells, see our guide to the types of stem cells.

Where are stem cells found in the human body?

Every adult carries stem cells. Their job is to replace and repair cells in the tissue where they live. Two examples are hematopoietic stem cells in the bone marrow, which maintain your blood cells and immune system, and mesenchymal cells found in different tissues, which support bone, cartilage, muscle and fat (Cleveland Clinic).

Source	Main stem cells	Potency	Main uses today
Early embryo (blastocyst)	Embryonic stem cells	Pluripotent	Research
Bone marrow	Hematopoietic and mesenchymal cells	Multipotent	Blood stem cell transplants; regenerative research
Fat (adipose tissue)	Mesenchymal stromal cells	Multipotent	Regenerative research and clinical studies
Umbilical cord blood (donated)	Hematopoietic stem cells	Multipotent	Transplants; research
Adult cells reprogrammed in a lab	Induced pluripotent stem cells (iPSCs)	Pluripotent	Research and early trials

What does multipotent mean?

Potency describes how many kinds of cells a stem cell can produce. Scientists use a simple ladder, summarized in reviews such as Zakrzewski et al.:

• Totipotent (sometimes called omnipotent): can form the embryo and the structures around it, such as the placenta. The fertilized egg (zygote) is the example.
• Pluripotent: can become cells of all three germ layers, but not the placenta. Embryonic stem cells and iPSCs.
• Multipotent: can become several related cell types within one family. Blood stem cells and mesenchymal stromal cells.
• Oligopotent: limited to a few cells of one lineage, such as a myeloid stem cell that makes white blood cells but not red ones.
• Unipotent: produce only one cell type while still dividing repeatedly, for example precursors of a single type of skin cell.

A multipotent stem cell, then, is a cell that can renew itself and turn into a limited set of specialized cells. Two standard examples:

• Hematopoietic stem cells produce red cells, white cells and platelets, but not bone or nerve.
• Mesenchymal stromal cells must, by the definition of the International Society for Cellular Therapy, turn into bone-forming, fat and cartilage cells in the lab, carry certain surface markers and lack others (Dominici et al., 2006).

Most adult stem cells are multipotent. That is a limitation and a safety feature at the same time: they cannot become every tissue, but they also lack the unlimited growth potential of pluripotent cells.

How do researchers and doctors get stem cells?

Embryonic stem cells

Human embryonic stem cell lines were first derived in 1998 from blastocysts, embryos a few days old. The cells could form tissue from all three germ layers (Thomson et al., Science). Researchers obtain them from donated embryos made during in vitro fertilization (Cleveland Clinic).

Induced pluripotent stem cells

In 2007 a Japanese team turned adult human skin cells into pluripotent stem cells by switching on four genes. The reprogrammed cells behaved like embryonic stem cells and formed teratomas, a type of tumor containing mixed tissues, when tested in animals (Takahashi et al., Cell). That tumor-forming ability is why pluripotent cells are not injected directly into patients.

Adult and birth-tissue stem cells

Adult stem cells are collected from donated tissue such as bone marrow or fat, and hematopoietic cells are also collected from donated umbilical cord blood (Cleveland Clinic). Depending on the product, the cells are used soon after collection or grown in a laboratory to increase their number, which is where manufacturing standards matter most.

Does the source matter for treatment?

Yes, in three ways: potency, safety testing and regulation. A cell’s origin affects what it can become, which infections and quality checks the lab must screen for, and how regulators classify it. The ISSCR advises patients to ask exactly what is being injected, where it comes from and how it is prepared (ISSCR guide). Ask us where the cells are processed and for the lab’s INVIMA certification; our page on stem cell therapy legality in Colombia explains it. Cell source also affects side effects, which we cover in stem cell therapy side effects.

When another treatment is the better choice

Some uses of stem cells are established medicine: blood stem cell transplants for leukemia, myeloma and certain blood disorders (Cleveland Clinic). Regenerative uses for joint and back pain are different: they are not FDA approved; read what FDA approval means. If your problem is mechanical, such as a complete tendon tear, an unstable joint or end-stage arthritis, surgery is the better path regardless of where the cells come from.

Where stem cell therapy fits

Regenerative treatment for pain and function works with multipotent mesenchymal cells, which we explain in our guide to mesenchymal stem cell therapy. Candidates usually have partial damage and a clear diagnosis; people with active infection or cancer are not candidates. See our stem cell therapy protocols for how treatment is organized.

Next step

If you are considering treatment, send your records for a free case review. Dr. Catalina Henao reviews your history and imaging, answers your questions about how the cells are prepared, and you receive a written quote before you buy flights. Request your free case review.

Frequently asked questions

Where are stem cells located in the body?

Adult stem cells live in many tissues. The best known are in the bone marrow, which holds blood-forming stem cells and mesenchymal cells, and in fat. Umbilical cord blood is another source collected at birth.

What is a multipotent stem cell?

A multipotent stem cell can renew itself and turn into several related cell types, but not every cell in the body. Blood stem cells and mesenchymal stromal cells are the classic examples.

What is the difference between multipotent and pluripotent?

Pluripotent cells, such as embryonic stem cells and iPSCs, can become any cell of the body. Multipotent cells are limited to one family of cells, for example bone, cartilage and fat for mesenchymal stromal cells.

Are adult stem cells multipotent?

Most are. Adult stem cells are generally multipotent or unipotent; they renew the tissue they live in rather than building new organs.

What is a unipotent stem cell?

A unipotent stem cell can divide repeatedly but forms only one cell type, for example precursors that produce a single type of skin cell. It sits at the bottom of the potency ladder, below multipotent and oligopotent cells.

Where do stem cells for research come from?

From donated adult tissue, donated umbilical cord blood, donated embryos created during in vitro fertilization, and adult cells reprogrammed in a lab into induced pluripotent stem cells.

Sources

• Cleveland Clinic: What Are Stem Cells?
• Zakrzewski W, et al. Stem cells: past, present, and future. Stem Cell Res Ther. 2019
• Dominici M, et al. Minimal criteria for defining multipotent mesenchymal stromal cells (ISCT position statement). Cytotherapy. 2006
• Thomson JA, et al. Embryonic stem cell lines derived from human blastocysts. Science. 1998
• Takahashi K, et al. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell. 2007
• ISSCR: A Guide to Stem Cell Treatments