Potency narrows as cells commit
Stem cells are ranked by potency, meaning the range of cell types they can become. A totipotent cell, such as the fertilized egg and its earliest divisions, can form every cell type plus the placenta. Pluripotent cells, like those of the early embryo, can become any body cell type but not the supporting placental tissues.
Below them, multipotent cells are limited to a related family of cell types, oligopotent cells to a few, and unipotent cells to just one. As development proceeds, cells generally move down this hierarchy, trading breadth of potential for specialized function.
Why the hierarchy is studied and where caution applies
Adult tissues keep multipotent stem cells, such as blood-forming cells in bone marrow, to replace cells lost to normal turnover and injury. Researchers can also reprogram mature cells back toward a pluripotent state, which reshaped how rigid this ladder was once thought to be.
Clinical stem cell therapies are well established for a narrow set of conditions, while many advertised treatments are unproven. This is general educational information about cell biology, not medical advice; consult a qualified professional before pursuing any therapy.