A certified regenerative medicine physician explains how adipose-derived stem cells work — from the basics to safety and what to expect
The term “stem cells” has been showing up everywhere lately — in beauty ads, wellness supplements, the health routines of international celebrities, and medical news. No matter where you look, the phrase keeps appearing.
“Rejuvenation at the cellular level.”
“Anti-aging with stem cells.”
“The era of regenerative medicine is here.”
And yet, for most people, the question of what stem cells actually are still doesn’t have a clear answer.
You might be wondering:
- ▶How are they different from ordinary cells?
- ▶Why is everyone in both medicine and beauty talking about them right now?
- ▶What do they have to do with “regenerative medicine” or “stem cell therapy”?
- ▶We hear that overseas, the field is far ahead — but where does Japan stand?
- ▶And why is the stem cell derived from fat at the center of it all?
This article is a beginner’s guide written to answer exactly these questions, one by one.
The guiding belief at Ginza YR Clinic is simple.
How young you feel and how much vitality you carry isn’t written in your age — it’s written in your cells.
That’s why, before considering any treatment, we think the most important first step is to genuinely understand what cells are and how they work.
※ This article is for general medical information purposes only and does not guarantee any specific outcomes or treatment results.
So, What Exactly Are Stem Cells?
Put simply, stem cells are the body’s master renewal cells — the source from which all other cells are continuously replenished.
The human body is made up of roughly 37 trillion cells — and the vast majority of them have a lifespan, constantly being renewed and replaced:
The whole system of renewal and repair runs on stem cells.
A Simple Way to Picture It
Think about a tree. The trunk gives rise to all the branches — and the “stem” in stem cells carries the same idea. One stem cell can branch out into many different types of cells, depending on what the body needs at any given moment.
Stem cells are the starting point of cellular differentiation. A single stem cell can, under the right conditions, become a skin cell, a blood vessel cell, or a bone cell. That flexibility is what sets them apart from ordinary cells.
The Difference Between Stem Cells and Regular Cells
An ordinary skin cell can only ever be a skin cell. A liver cell will always be a liver cell. And once its lifespan is up, that’s it.
Stem cells are different. They have two abilities that ordinary cells simply don’t:
Together, these two abilities are what make it possible to support the body’s natural repair process when tissue is damaged.
Think about how a cut healed so quickly when you were young, but now seems to take much longer. That’s not your imagination. It’s because the number of stem cells in your body — and their activity level — naturally decreases as you age.
The repeated physical stress of sports and exercise, years of accumulated fatigue, the lingering effects of old injuries — the damage that builds up quietly through everyday life eventually shows up as cellular wear throughout the body.
Why Everyone Is Talking About Stem Cells Right Now
One pivotal moment that brought stem cells into mainstream awareness was Professor Shinya Yamanaka’s Nobel Prize in 2012. His breakthrough in developing iPS cells — a method for artificially creating stem cells — was celebrated around the world, and almost overnight, “stem cells” became a topic of everyday conversation.
That said, iPS cells and ES cells (derived from fertilized eggs) — the ones that tend to make the headlines — are mostly still in the research phase, and widespread clinical use remains some way off.
What fewer people realize is this: our bodies already contain stem cells naturally. These are called somatic stem cells, or adult stem cells. And the stem cells that are actually being used in clinical treatment today are these naturally occurring ones — not the lab-created kind.
The most prominent of these is the adipose-derived stem cell (ASC) — the focus of this article.
How Far Has the Field Advanced — Overseas vs. Japan?
Many people assume that “stem cell treatment is more advanced abroad.” It’s true that in the US, South Korea, Thailand, and elsewhere, there are many clinics offering stem cell therapies as private treatments. But the standard to which these are considered “established medicine” varies enormously from country to country. In places with looser regulations, treatments with limited scientific backing have raised concerns within the medical community.
Japan, by contrast, operates under the Act on the Safety of Regenerative Medicine, enacted in 2014, which sets strict requirements for any treatment involving stem cells. Only institutions and physicians who have formally registered with the Ministry of Health, Labour and Welfare are permitted to offer these treatments. Japan’s regulatory framework is considered among the strictest in the world.
Rather than “overseas is more advanced” —
“Japan is making steady, careful progress in clinical application — within one of the most rigorous safety frameworks anywhere.” That’s the more accurate picture.
What Are Adipose-Derived Stem Cells (ASC)? — And Why Are They the Leading Choice Today?
MEDICAL SUPERVISION
Dr. Junya Higuchi, Director — Ginza YR Clinic
While the number of physicians offering regenerative medicine is growing, doctors who can clinically diagnose musculoskeletal conditions — problems with joints, bones, and muscles — perform regenerative treatments, and then design a full return-to-activity plan remain extremely rare in Japan.
Not All Stem Cells Are the Same
Within the category of somatic stem cells, there is a specific group that stands out: cells capable of differentiating into bone, cartilage, fat, muscle, blood vessels, and more. These are called mesenchymal stem cells (MSC).
The name sounds technical, but there’s no need to memorize it. Just think of them as “a versatile type of stem cell well-suited for supporting tissue repair throughout the body.”
Where in the Body Are Stem Cells Harvested From?
“If you need stem cells, wouldn’t bone marrow or blood make more sense as a source? Why fat?” It’s a fair question. The answer is that mesenchymal stem cells can actually be harvested from several different locations in the body. The four main sources are:
| Source | Impact on Body | Yield | Cell Origin |
|---|---|---|---|
| Fat (ASC) | Minimal (local anesthetic, ~2mm incision) | Very high (some reports cite ~500x more than bone marrow) | Autologous |
| Bone marrow (BMSC) | Relatively high | Low | Autologous |
| Dental pulp (DPSC) | Depends on extraction timing | Moderate (young, highly active cells) | Autologous |
| Umbilical cord / cord blood | Virtually none for the patient | High | Allogeneic (donor) |
Your Own Cells vs. Someone Else’s Cells
In Japan, the vast majority of clinically applied regenerative treatments use autologous cells. Among those options, adipose-derived stem cells (ASC) — which are easy to collect, available in large quantities, and relatively resistant to age-related decline — have become the most widely used choice.
What Does the Extraction Procedure Actually Involve?
What’s collected is a very small amount of subcutaneous fat from the abdomen — roughly equivalent to two or three grains of rice. The procedure is done under local anesthesia, with an incision of about 2mm. No hospital stay is needed, and patients go home the same day. The cells are then cultured and multiplied to hundreds or thousands of times the original number, and reintroduced into the body through intravenous infusion or localized injection. That is the basic process of adipose-derived stem cell therapy.
ASC, ADSC, Adipose Stem Cells — Why So Many Names?
- ASC: Adipose-derived Stem Cell
- ADSC: Adipose tissue-Derived Stem Cell
- Fat stem cells / adipose-derived mesenchymal stem cells: Common descriptive terms
All of these refer to exactly the same cells. Throughout this article, we use the most widely recognized term: ASC.
How Do ASCs Work Inside the Body? Three Key Mechanisms
Once reintroduced into the body, how do ASCs participate in the repair process? Current research points to three primary mechanisms.
Moving Toward Where They’re Needed — The Homing Effect
ASCs have been shown to detect areas of injury or inflammation in the body and migrate toward them. Think of it like a first responder heading straight to the scene. Researchers believe this property — ASCs concentrating at the target site after being introduced into the bloodstream — is what makes systemic delivery of regenerative treatment possible.
Signaling to Surrounding Cells — The Paracrine Effect
Once they arrive at the target area, ASCs release substances called growth factors and cytokines. Research suggests these molecules may stimulate the repair activity of nearby cells and help modulate inflammation. What makes this particularly interesting is that ASCs don’t just potentially contribute to new tissue — they may also “wake up surrounding cells and get them working again,” creating a kind of cascade effect.
Becoming the Cells the Body Needs — Differentiation
Given the right conditions, ASCs have been reported to differentiate into bone, cartilage, fat, blood vessel cells, and more — potentially contributing cells that are in short supply at the site of damage.
Research suggests these three mechanisms may work in combination — and this is what distinguishes ASC therapy from conventional medications and injections. Where traditional treatments typically aim to suppress symptoms, ASC therapy is believed to potentially work at the tissue level itself. Individual results vary, and outcomes are not guaranteed.
A Growing Trend Overseas — Why More People Are Paying Attention
In Japan, regenerative medicine still carries a sense of novelty. Abroad, however, athletes and public figures have been reported using stem cell therapy for injury recovery and physical maintenance for years.
- Cristiano Ronaldo: In 2016, The Sun reported that he underwent regenerative medicine using his own cells to treat a hamstring injury and knee ligament damage.
- Rafael Nadal: In 2014, reports emerged that he chose stem cell therapy for a chronic knee condition.
- Tiger Woods (golf) and Kobe Bryant (basketball) are also among those reported to have turned to regenerative medicine to extend their careers.
These are overseas media reports, and outcomes vary from person to person. Japan’s regulatory framework also differs considerably from that of other countries, so “someone famous did it abroad” should not be taken as a direct recommendation.
What these stories do point to is a broader shift in thinking. People who rely heavily on their bodies, and who want to maintain good physical condition for as long as possible, are increasingly willing to invest in supporting their physical foundation proactively. The mindset is moving away from “treat it when something goes wrong” toward “taking an active interest in the body’s natural capacity for repair.”
Quietly Growing in Japan, Too
Due to strict regulations, overt promotion of regenerative medicine in Japan is limited. In practice, though, executives, physicians, lawyers, and professional athletes — people whose physical condition directly affects the quality of their work — have been quietly incorporating regenerative medicine into their health routines.
- —Someone who loves golf but has started noticing nagging pain in the elbow or shoulder
- —Someone with a demanding schedule who finds that fatigue isn’t clearing the way it used to
- —A family member looking for a non-surgical option for a parent’s knee pain
- —Someone who has been active for decades and wants to keep doing what they love well into their 50s and 60s
What these people share is a common mindset: rather than waiting for problems to appear, they want to “build a solid physical foundation before things start to go wrong.”
Where ASC Therapy Is Being Applied
ASC therapy is currently being researched and applied across a range of medical fields. Here’s a brief overview of the main areas.
Orthopedics — Joints, Cartilage, and the Musculoskeletal System
This is where the largest body of clinical evidence has accumulated.
- Knee osteoarthritis
- Hip osteoarthritis
- Chronic low back pain (discogenic or facet joint-related)
- Shoulder and elbow pain (golfer’s elbow, tennis elbow, etc.)
- Recovery care following sports injuries (knee and Achilles tendon issues in runners and endurance athletes)
Intervertebral discs and articular cartilage are naturally low in blood supply, which limits their ability to repair on their own. Research into how ASCs may support healing in these tissues is actively underway at the University of Tokyo’s Department of Orthopedic Surgery / Cartilage Regenerative Medicine and Tokai University’s Department of Orthopedic Surgery, among others.
Anti-Aging and Aesthetic Medicine
- Supporting changes in skin firmness and elasticity
- Whole-body aging care through intravenous infusion
- Applications for hair and scalp health (currently in the research phase)
As we age, the body’s natural supply of stem cells decreases. The concept behind this area of research is to culture a patient’s own ASCs and reintroduce them, with the aim of supporting the body’s natural repair functions to some degree.
Other Areas of Research
Research into applications for chronic inflammatory conditions, immune system irregularities, and a wide range of other health concerns is ongoing worldwide. Many of these, however, have not yet been established as standard, insured treatments — they are offered as private medical services. Results vary by individual, and outcomes are not guaranteed.
Safety and Risk — The Honest Picture
When you hear “new treatment,” the immediate question is often: “But is it safe? Is it legitimate?” That’s a completely reasonable thing to wonder, and we want to address it directly.
Japan’s Regulatory Framework
Japan operates under the Act on the Safety of Regenerative Medicine (enacted November 2014), which places strict legal requirements on any treatment involving stem cells. To offer ASC therapy under this law, a clinic must:
Prepare a treatment plan and have it reviewed by a Specially Certified Regenerative Medicine Committee approved by the Minister of Health, Labour and Welfare
After approval, submit a formal notification to the Ministry of Health, Labour and Welfare and obtain a provision plan registration number
Have all cell culturing carried out at a Cell Processing Center (CPC) accredited by the Ministry of Health, Labour and Welfare
※ Being “registered” means the clinic has fulfilled the required legal procedures — it does not mean the government has endorsed the effectiveness of the treatment.
What the Research Says About Side Effects
Because the treatment uses the patient’s own cells, immune rejection is considered to be inherently low risk.
2021 meta-analysis — 62 clinical trials, 3,546 patients worldwide
- No statistically significant differences in mortality, infection rates, or cancer incidence were found between those who received the treatment and those who did not
- Some patients experienced temporary reactions including mild fever, slight pain at the injection site, and minor bruising
- These were generally considered to be normal physiological responses as the body’s healing process initiates
That said, this does not mean the treatment is entirely without risk. Because needles are used, some possibility of bleeding or infection cannot be completely ruled out. And as with any medical treatment, results differ from person to person.
Three Things to Check Before Choosing a Clinic
Why Patients Choose Ginza YR Clinic
Ginza YR Clinic is a regenerative medicine specialty clinic located in the Ginza district of Tokyo, offering stem cell therapy, immune cell therapy, and PRP therapy as its core treatments — alongside joint care, return-to-sport rehabilitation, anti-aging, and aesthetic medicine.
Having the same physician handle diagnosis, treatment, and rehabilitation planning from start to finish is the core strength that distinguishes our approach.
OUR PHILOSOPHY
The “Ageing Well” Philosophy
Not fighting against aging, but moving through every stage of life with health and vitality, in a way that suits who you are. Aging isn’t something that only happens to older people. Even in your 20s or 30s, the body is already changing at the cellular level. No matter where you are in life, you are already on the path of Ageing Well.
Frequently Asked Questions
How young you feel and how much vitality you carry isn’t written in your age — it’s written in your cells.
Before making any treatment decision, start by understanding what’s happening inside your own body. We hope this article has given you a meaningful place to begin.
▶ Consultations and Appointments
📍 Css Building III 7F, 6-5-13 Ginza, Chuo-ku, Tokyo 104-0061
🚇 Tokyo Metro Ginza Station, 5-minute walk from Exit C3 or C2
References
- Ministry of Health, Labour and Welfare: Act on the Safety of Regenerative Medicine, etc.
- Japanese Society for Regenerative Medicine: Official Website
- University of Tokyo, Department of Orthopedic Surgery / Cartilage Regenerative Medicine: Official Website
- Tokai University, Department of Orthopedic Surgery
- Thompson M, et al. Cell therapy with intravascularly administered mesenchymal stromal cells — a systematic analysis of peer-reviewed studies. (2020)
- Zuk PA, et al. Human adipose tissue is a source of multipotent stem cells. Mol Biol Cell. 2002.
※ Results vary by individual. All services are private medical care (not covered by health insurance). This article is for general medical information purposes and does not guarantee any specific outcomes.
