Therapeutic Cloning

Therapeutic cloning is one of the most frequently confused terms in science writing. It uses the same starting technique as reproductive cloning — somatic cell nuclear transfer — but its purpose is entirely different. The goal is not to produce a person. The goal is to study cells.

The basic idea

In therapeutic cloning, researchers use SCNT to produce early-stage cells whose nuclear DNA matches a specific donor. From those cells, they can sometimes derive stem cells — unspecialised cells that can be coaxed into many different cell types, like neurons, heart-muscle cells, or pancreatic cells.

Those laboratory-derived cells can then be used in three broad ways:

• To study disease. A stem-cell line derived from a patient with a particular condition can be turned into the cell type affected by that disease, giving researchers a model to investigate.
• To screen potential treatments. Candidate drugs can be tested on cells, sometimes more directly than on animal models.
• To explore future cell-based therapies. If cells matched to a particular individual could be produced safely, they might one day be used in replacement therapies. This remains research, not clinical practice.

What therapeutic cloning is not

• It is not a reproductive procedure. The cells are studied in the laboratory, not implanted.
• It is not a service offered to patients. There is no “therapeutic cloning clinic.”
• It is not a path to making genetically identical people.
• It is not the same as ordinary stem-cell research, much of which uses cells that have nothing to do with cloning at all.

How it relates to stem-cell research

Therapeutic cloning is one of several ways to produce pluripotent stem cells — cells capable of becoming many different cell types. Two others are commonly used in current research:

• Human embryonic stem cells (hESCs) are derived from very early embryos donated from in-vitro fertilisation procedures, not from cloning.
• Induced pluripotent stem cells (iPSCs) are produced by reprogramming ordinary adult cells in the lab. They do not require an embryo at all.

The arrival of iPSCs in 2006–2007 shifted much of the work that once relied on therapeutic cloning. Today, most pluripotent stem-cell research uses iPSCs because they are easier to produce and do not raise the same ethical questions about embryos. Therapeutic cloning still has a research role but is no longer the only way to study donor-matched pluripotent cells.

Why it is regulated

Even though no one is being born from therapeutic cloning, it is still tightly regulated because it produces early-stage human embryos in a laboratory. Different jurisdictions assign different moral weight to those embryos. The common policy patterns include:

• Permitted under licence. The work is allowed under strict oversight, with limits on how long embryos can be maintained and a strict prohibition on reproductive use.
• Permitted only with donated IVF embryos. SCNT-based work may be limited or banned.
• Prohibited entirely. All forms of human cloning, therapeutic or reproductive, are banned.

For an overview of the broader legal picture see our explainer on whether human cloning is legal.

The ethical debate

Therapeutic cloning is debated because reasonable people disagree about the moral status of early embryos. Some hold that an early embryo is a form of human life deserving of strong protection. Others hold that very early cellular structures are not morally equivalent to people. Most jurisdictions sit somewhere in between, allowing carefully limited research while prohibiting other uses.

For a longer treatment of these arguments see our bioethics of cloning guide.

Related reading

• Somatic cell nuclear transfer
• Reproductive cloning
• Stem cells and cloning
• Therapeutic vs reproductive cloning
• Cloning ethics