Is It Possible to Clone a Human? Science & Ethics Explained

Is it possible to clone a human safely and effectively?

When the famous photograph of Dolly the cloned sheep was taken in Scotland on September 2, 1997, many believed it would usher in a golden age of cloning [1]. The animal had already made global headlines in 1996 after becoming the first mammal successfully cloned from an adult cell. While many commentators at the time assumed widespread cloning would quickly follow, the reality of a human clone remained years away at best.

When debating human cloning pros and cons, some argue that clones could play a crucial role in eradicating genetic diseases. Others believe cloning could eventually eliminate birth defects, despite a 1999 study by a group of French scientists which found that cloning might actually increase the risk of birth-related anomalies.

Since Dolly's success, there have been various unverified claims about successful human cloning programs. In 2002, a French chemist affiliated with a UFO-based religion—which believes extraterrestrials created humanity—claimed her team had successfully delivered the first cloned human, named Eve. However, she never provided any proof, and the claim is universally regarded as a hoax.

So, nearly 30 years after Dolly, why haven't humans been cloned? Is it primarily due to ethical reasons, are there specific technological barriers, or is the process simply not worth the effort?

The history of human cloning research and mammalian anomalies

According to the National Human Genome Research Institute, "cloning" is a broad term used to describe a variety of processes and methods. The ultimate goal, however, is always to create genetically identical copies of a biological entity.

Any attempt to clone a human would likely rely on reproductive cloning methods. This technique involves taking a mature somatic cell, such as a skin cell, extracting its DNA, and transferring it into a donor egg. The egg is then allowed to develop in a test tube before being implanted into a surrogate's womb [2]. While scientists have cloned numerous mammals—including cattle, goats, rabbits, and cats—humans have never made the list.

The primary reason is that there is currently no justifiable argument for creating human clones, as the process is incredibly risky. Furthermore, there are countless ethical problems associated with human cloning, encompassing psychological, social, and physiological risks. The procedure carries an exceptionally high probability of loss of life, which inherently violates the fundamental principles of human dignity, freedom, and equality.

Another major issue: human cloning pros and cons

The fundamental problem with human cloning is that, rather than creating an exact replica of the original person, the process would create a unique individual with their own thoughts and opinions.

We are already familiar with natural clones—identical twins are essentially clones of one another—which makes it clear that they are not the exact same person [3]. Human clones would share the same genetic makeup as their donor, but they would not share a personality, moral compass, or sense of humor. In other words, clones would be entirely unique individuals.

Humans are much more than the product of their DNA. While genetic material can be replicated, it is impossible to exactly duplicate a person's environment and upbringing to manufacture a standardized human experience. So, would cloning humans actually offer any scientific or practical benefits?

The ethical issues surrounding cloning are impossible to ignore. However, if moral considerations were entirely removed from the equation, there would be a theoretical benefit to creating genetically identical humans for research purposes.

Fortunately, other scientific breakthroughs have rendered the potential benefits of human cloning largely obsolete. The idea of using cloned embryos to produce human embryonic stem cells—identical to a donor's cells—became irrelevant with the discovery of induced pluripotent stem cells (iPSCs). These are adult cells that have been reprogrammed to behave like early developmental cells.

Building on this concept, Japanese stem cell researcher and 2012 Nobel laureate Shinya Yamanaka discovered how to revert adult mouse cells to an embryo-like state using just four genetic factors. The following year, Yamanaka and renowned American biologist James Thomson successfully achieved the same result with human cells.

When cells are reprogrammed back into an embryonic pluripotent state, they provide an unlimited source of any type of human cell needed for therapeutic purposes. Therefore, instead of relying on embryos, scientists can effectively achieve the same results using ordinary skin cells. Because of this technological advancement, using cloned embryos is now considered a scientifically inferior approach for disease modeling, drug discovery, and regenerative medicine.

Ultimately, human cloning is no longer the most compelling area of genetic research. Today, human germline genome editing captures far more scientific and public interest. Many are fascinated by the concept of creating "designer babies" through germline editing, a process that introduces permanent, heritable changes to an individual's genome.

This type of editing remains highly controversial. Applying genome editing technologies to human embryos raises profound ethical, social, and safety concerns, particularly because any modifications to the human genome would be passed down to future generations.

Despite not being fully mastered, germline editing offers the ability to target multiple genes with greater precision and efficiency. As a result, it is far more likely to dominate future scientific research than traditional reproductive cloning.