Stem Cell (줄기세포): Definition, Types, Research, Established Medical Uses and Cosmetic Claims

What is a stem cell (줄기세포)?

The US National Cancer Institute's dictionary defines a stem cell as "a cell from which other types of cells develop" [2]. MedlinePlus, the consumer health service of the US National Library of Medicine, describes stem cells as cells that can develop into many different cell types in the body. It says they serve as a repair system for the body [1]. Two properties define a stem cell. The first is self-renewal: it can divide and make more stem cells. The second is differentiation: it can give rise to specialized cells such as muscle, blood or brain cells [1]. The Korean term is 줄기세포.

Potency: how many cell types a stem cell can produce

Stem cells are often grouped by potency, meaning the range of cell types they can become.

• Pluripotent cells can form the derivatives of all three embryonic germ layers. Embryonic stem cells and induced pluripotent stem cells fall into this group [3][4].
• Multipotent cells are limited to one family of related cells. Blood-forming (hematopoietic) stem cells, for example, rebuild the blood and immune cell lineages after transplantation [5].

Main types of stem cells

MedlinePlus groups stem cells into two broad categories: embryonic and adult [1]. Reprogrammed iPSCs are usually treated as a third category because they come from adult cells but behave like embryonic ones [4].

Stem cell research (줄기세포 연구): key milestones

• 1962: John Gurdon replaced the nucleus of a frog egg cell with the nucleus of a mature intestinal cell. The egg developed into a normal tadpole, showing that cell specialization can be reversed [4].
• 1998: Thomson and colleagues published human embryonic stem cell lines in Science (volume 282, pages 1145–1147) [3]. After 4 to 5 months of growth in the lab without specializing, the cells could still form derivatives of all three germ layers [3].
• 2006: Shinya Yamanaka showed that adding a small set of genes to mature mouse fibroblasts could reprogram them into induced pluripotent stem cells [4].
• 2012: Gurdon and Yamanaka shared the Nobel Prize in Physiology or Medicine "for the discovery that mature cells can be reprogrammed to become pluripotent" [4].

What stem cell research is used for

Researchers use stem cells in three main ways:

• Disease modelling: skin cells from patients can be reprogrammed and compared with healthy cells to study how a disease works [4].
• Drug testing: lab-grown cells can be used to test candidate drugs.
• Possible future therapies: MedlinePlus lists research interest in conditions such as Parkinson's disease, Alzheimer's disease, spinal cord injury, heart disease, diabetes and arthritis. It notes that stem cells "may one day" be used to make cells and tissues for therapy [1].

Stem cells in medicine (줄기세포 의료): established uses

Blood stem cell transplantation

Blood stem cell transplantation is the best-established stem cell treatment. The NCI explains that stem cell transplants restore blood-forming stem cells in people whose own cells were destroyed by high-dose chemotherapy or radiation therapy [5].

• Sources of cells: peripheral blood (the most common), bone marrow or umbilical cord blood [5].
• Donor types: autologous (the patient's own cells), allogeneic (from a donor) or syngeneic (from an identical twin) [5].
• Main uses: leukaemia, lymphoma, multiple myeloma and myelodysplastic syndromes [5].
• Complications: the procedure has serious risks, including graft-versus-host disease after allogeneic transplants [5].

Approved stem cell products

• United States: the FDA states that the only FDA-approved stem cell products are blood-forming stem cells (hematopoietic progenitor cells) from umbilical cord blood. They are approved for disorders of the blood-forming system [7].
• European Union: Holoclar is made from a patient's own corneal cells, which include limbal stem cells, grown in the lab. It received conditional marketing authorisation on 17 February 2015 for moderate to severe limbal stem cell deficiency caused by eye burns. This was converted to standard authorisation on 22 February 2024 [6].
• South Korea: as of February 2019, Korean trade press reported four approved stem cell therapeutics [9]:

Source for the table: [9].

Stem cell procedures (줄기세포 시술) outside approved uses

The FDA warns about wide marketing of unapproved "regenerative medicine" products. It lists these as unapproved when offered outside FDA-overseen clinical trials: stem cells, stromal vascular fraction (fat-derived cells), umbilical cord blood, amniotic fluid, Wharton's jelly, ortho-biologics and exosomes [7].

The FDA says it has received reports of harm after such products were used. These include blindness, tumour formation, infections including sepsis, neurological events and unwanted inflammatory responses [7]. It also states that if you are charged for these products, or offered them outside a clinical trial, "you are likely being deceived" [7].

Stem cell cosmetic surgery (줄기세포 성형) and aesthetic claims

"Stem cell" is widely used in cosmetic and plastic surgery marketing. The evidence for these uses is limited.

• What the research shows: a 2024 systematic review in Cureus looked at stem cell use in plastic surgery, including fat grafting, facial rejuvenation and wound healing. It found that stem-cell-based products for aesthetic medicine had not received FDA approval. Most studies were small, had short follow-up and used protocols that differed from study to study [11].
• Fat-derived preparations: many procedures marketed as stem cell cosmetic surgery use cells taken from fat. Stromal vascular fraction is one of the products the FDA lists as unapproved outside clinical trials [7]. worldwiki.io covers SVF, adipose-derived stem cells and fat grafting on separate pages.
• Cosmetics in Korea: the Ministry of Food and Drug Safety (MFDS) prohibits labels or ads that suggest a product contains stem cells. Products may use human stem cell culture medium only if they meet safety standards set in 2010 .

Regulation of stem cell treatment in Korea

Korea amended its Advanced Regenerative Medicine and Advanced Biopharmaceuticals Act (첨단재생바이오법) on 20 February 2024. The amendment took effect on 21 February 2025 [10]. According to a law firm's summary of the changes [10]:

• Treatment is now allowed, not only research, with procedures sorted by risk level.
• Eligible patients are limited to people with serious, rare or intractable diseases who have no alternative treatment.
• Each treatment plan is reviewed by a government committee, within 120 days.
• Treatment is delivered by regenerative medicine institutions designated by the Minister of Health and Welfare.
• Patients may be charged, but institutions must report treatment costs to the authorities.

How to evaluate a stem cell hospital (줄기세포 병원, 줄기세포 전문병원, 줄기세포 성형외과)

A clinic's name, or advertising phrases such as "stem cell specialist," do not show that a particular product or procedure has been approved. The ISSCR (International Society for Stem Cell Research) and regulators suggest these checks [7][8]:

1. Check approval. Ask whether the specific product is approved for your condition by a national regulator such as the FDA, the European Medicines Agency or the MFDS [8].
2. Check trial oversight. If the treatment is offered as research, ask for proof of approval from an independent ethics committee (IRB) and from a regulator [8].
3. Check designation in Korea. Confirm that regenerative medicine treatment is given by a designated institution under an approved treatment plan [10].
4. Watch for warning signs. These include claims based mainly on patient testimonials, the same treatment offered for many unrelated diseases, unclear consent documents and claims that there is no risk [8].
5. Ask about costs. The ISSCR notes that it is not customary to pay to take part in a clinical trial. It also advises asking who pays for emergency care if something goes wrong, especially abroad [8].
6. Get a second opinion from a doctor you trust before agreeing to treatment [8].