How does Stem Cell Therapy Work? A simple explanation

Stem cell therapy works by using your body’s own natural repair system to heal injuries and fight disease. Doctors take stem cells—special cells that can turn into different types of tissue—and inject them into the area that needs help. Once inside, these cells either become the missing pieces or send out signals to kickstart the healing process.

It’s kind of like planting seeds in a garden. If the conditions are right, the seeds grow into healthy plants, repairing the damaged soil around them. That’s why stem cell therapy is being used for everything from joint pain to autoimmune conditions.

In this guide, we’ll break down exactly how it works in the most simple way, step by step, so you know what to expect.

How Do Stem Cells Repair and Regenerate the Body?

Stem cells repair tissue by turning into the needed cell type or by releasing signals that help the body heal itself. Depending on the injury, they can either replace damaged cells directly or trigger other cells to start the repair process.

Here’s how it works:

1. Differentiation. How Stem Cells Turn Into New Cells (and Why It Doesn’t Always Work)
   Stem cells are special because they can turn into different types of cells—a process called differentiation. If you have damaged cartilage, for example, stem cells injected into your knee might become new cartilage cells, helping with repair.
   
   But here’s the catch—this doesn’t always happen perfectly. Sometimes, the stem cells don’t turn into the right type of cell, or they struggle to integrate into the tissue. That’s why results can vary from person to person. Scientists are still working on ways to improve this process, making sure stem cells can be more predictable and effective in treatments.
2. Paracrine Signaling – Stem Cells as Messengers
   Not all stem cells work by replacing damaged tissue directly. Instead, many act like messengers, sending out chemical signals (growth factors and cytokines) that tell nearby cells to start repairing themselves. This is especially important for spinal cord injuries, autoimmune diseases, and brain conditions, where stem cells help calm inflammation and trigger natural healing.
3. Immunomodulation – Calming an Overactive Immune System
   Sometimes, the immune system does more harm than good. It attacks healthy tissue instead of protecting it. Stem cells help by calming this overreaction, reducing inflammation, and restoring balance. That’s why researchers are studying them for conditions like rheumatoid arthritis and multiple sclerosis, where the immune system mistakenly attacks the body.
4. Homing – How Stem Cells Know Where to Go
   Stem cells are naturally drawn to injury and inflammation. Almost like they have a built-in GPS. Once they enter the body, they follow distress signals from damaged areas and travel to where they’re needed most. This is why IV infusions of stem cells can be effective for diabetes, lung disease, and other systemic conditions. The cells find the problem areas on their own and start the healing process.
5. Regeneration – Repairing & Rebuilding Over Time
   Healing with stem cells doesn’t happen overnight. Once they reach the damaged area, they start rebuilding tissue, reducing scarring, and improving function. This process can take weeks or even months, depending on the condition and treatment. But over time, stem cell therapy can lead to stronger, healthier tissue and long-term improvements in the affected area.

What are the different types of Stem Cells?

Not all stem cells are the same, and only a few are actually used in therapy today. Here’s a quick breakdown:

Embryonic Stem Cells (ESCs)

 These can turn into any cell type. But they come with ethical concerns and a high tumor risk, so clinics don’t use them in treatments.

We know you might be having some concerns about Embryonic cells! We’ve put together more information on the issues around Embryonic cells in this article for you.

Induced Pluripotent Stem Cells (iPSCs)

 Scientists can reprogram regular cells into iPSCs, giving them the power of ESCs. But they’re still in the research phase because of safety concerns.

If you want to read more about IPSC cells, check out our article that goes in depth on how IPSC cells work here.

Mesenchymal Stem Cells (MSCs)

These are the all-stars of stem cell therapy. Found in bone marrow, fat, and umbilical cord tissue, they help repair joints, cartilage, and even reduce inflammation in autoimmune conditions. Most clinics use umbilical cord-derived MSCs because they work well across different patients.

Hematopoietic Stem Cells (HSCs)

These are the blood cell factories. They’re taken from bone marrow and umbilical cord blood and are mostly used for treating blood disorders like leukemia.

There are more types of Stem Cells, we put together an article specifically on the different types of Stem cells for you here

Can Stem Cells be rejected by my body?

Stem cell rejection isn’t a big concern for most therapies because clinics use mesenchymal stem cells (MSCs), which the immune system typically accepts without issue. But not all stem cells work the same way. Some, like embryonic stem cells (ESCs) and certain induced pluripotent stem cells (iPSCs), have a higher risk of rejection. Here’s which types of stem cells are most and least likely to be rejected:

Low Rejection Risk: Mesenchymal Stem Cells (MSCs)

• MSCs (from umbilical cord, fat, or bone marrow) are naturally immune-privileged, meaning the body doesn’t see them as a threat.
• This allows clinics to use donor MSCs (allogeneic therapy) without needing immune suppression drugs.
• Umbilical cord-derived MSCs (UC-MSCs) are even better because they come from newborn tissue, making them young, adaptable, and less likely to trigger rejection.

Medium Rejection Risk: iPSCs (Induced Pluripotent Stem Cells)

• iPSCs are reprogrammed from a patient’s own cells, so they should be immune-compatible.
• But research has shown that some iPSCs still cause an immune response, possibly due to incomplete reprogramming or “epigenetic memory” (cells remembering their original function).
• iPSCs are not used in clinical treatments yet—scientists are still figuring out how to make them safer.

High Rejection Risk: Embryonic Stem Cells (ESCs)

• ESCs are taken from embryos, which means they don’t match the patient’s immune system and are often seen as foreign by the body.
• This leads to high rejection rates, requiring immune suppression drugs if they were to be used.
• Clinics do NOT use ESCs in therapy, but researchers are exploring ways to modify them to avoid rejection.

How Scientists Are Solving Immune Rejection in Stem Cell Therapy

• Using Immune-Privileged Cells (Like MSCs)
  This is the current standard. Clinics use umbilical cord MSCs because they work across different patients without triggering rejection.
• Genetic Modification (CRISPR & Gene Editing)
  Scientists are testing CRISPR gene editing to alter stem cells so they avoid immune detection.
  Some experiments focus on removing certain cell markers that trigger an immune response
• Developing “Universal” Stem Cells
  Researchers are working on hypoimmunogenic stem cells. Genetically engineered to work in any patient without immune suppression.
  This could lead to off-the-shelf stem cell treatments that don’t require a perfect donor match.
  

Bottom Line: Should You Worry About Immune Rejection?

• No—most clinics use MSCs, which don’t trigger rejection.
• iPSCs & ESCs have higher rejection risks, but they aren’t used in therapy.
• Scientists are working on future solutions like gene-edited “universal” stem cells.

If you want to dig deeper into the science behind differentiation, immune responses, and more, check out this research paper completed in 2024. It’s got all the details, but it’s a long read!

How do they perform Stem Cell Therapy?

Stem cell therapy is a straightforward procedure where doctors collect stem cells—either from your own body or a donor—prepare them in a lab, and inject them where they’re needed. The goal? To kickstart healing, reduce inflammation, and repair damaged tissue. 

Here’s what actually happens, step by step:

1. Where the Stem Cells Come From
   Doctors first extract stem cells from your own body or use donated cells. The most common sources are:
   – Bone marrow – Often used for orthopedic and blood-related treatments.
   – Fat tissue (adipose-derived stem cells) – Easy to collect and rich in regenerative properties.
   – Umbilical cord blood – Donor cells that are young, potent, and widely used in treatments.
2. Preparing the Stem Cells
   Once collected, the stem cells go through a purification and processing stage to ensure only the most active and effective cells are used. Some clinics also expand the cells in a lab, increasing their numbers for a stronger therapeutic effect.
3. How Stem Cells Are Injected/Delivered
   Depending on the condition, stem cells are delivered in different ways:
   – Direct Injection – Used for joints, muscles, and soft tissue injuries like arthritis and torn ligaments.
   – IV Infusion – Best for autoimmune diseases, neurological conditions, and whole-body healing.
   – Surgical Application – Sometimes used in spinal cord injuries and organ repair where direct placement is required.
4. How Stem Cells Help the Body Heal
   Once inside the body, stem cells work in two main ways:
   – Regeneration – Some stem cells transform into the damaged tissue (e.g., cartilage in a joint, neurons in the brain).
   – Signaling & Repair – Others don’t become new cells themselves but release growth factors and anti-inflammatory signals that help surrounding cells heal.
5. Recovery & Follow-Up
   Some patients feel improvements within weeks, while others need months depending on their condition.

What diseases can be treated by Stem Cells?

Stem cell therapy is being explored for a myriad of medical conditions, including:

• Orthopedic Conditions: Helping bones, cartilage, and muscles bounce back.

• Neurological Disorders: Tackling conditions like Parkinson’s disease and multiple sclerosis.

• Cosmetic & Anti-aging Treatments: Helping conditions such as Hair loss and tackling signs of aging.
  
  To learn more about the conditions they can treat, we’ve got an article covering all the conditions here. Or check out our areas of treatment section.
  

Risks and Ethical Considerations of Stem Cell Therapy

Stem cell therapy holds incredible promise, but it’s not without risks and ethical concerns. Some potential issues include:

• Side Effects: Possible infections, or unintended cell growth.
• No Guarantee: Remember, there’s no guarantee it will work 100% for you specifically. There’s factors that affect success rates and whilst it can achieve amazing results, you’ve got to be aware it’s not a miracle cure.
• Where do clinics get donor stem cells? Most umbilical cord stem cells come from voluntary donations after birth, but not all clinics follow the same ethical standards. Are mothers fully informed about how their donation will be used? Are clinics following strict regulations to ensure quality and transparency? It’s worth asking how stem cells are sourced to make sure they come from properly regulated, ethical providers.

To learn more about the side effects, check out our article on Stem Cell Therapy Side Effects.

Recent Breakthroughs in Stem Cell Research

• IPSC Cells: The Abu Dhabi Stem Cells Center (ADSCC) has just developed clinical-grade iPSCs under Good Manufacturing Practice (GMP) protocols, meeting strict international standards in 2025.
• Parkinson’s Disease: In 2024, Japan became the first country to approve Stem Cell Therapy for Parkinson’s disease.

Thinking About Stem Cell Therapy? Here’s What You Should Know

Is Stem Cell Therapy Right for Me?

Patients with chronic injuries, degenerative conditions, and autoimmune diseases most commonly seek stem cell therapy. Stem Cells are also heavily used for cosmetic procedures and anti-aging treatments. Major factors that affect treatment results are your own physical condition, quality of clinic you go to, types & quantity of Stem Cells used. Keep in mind that while many achieve great results, no one can guarantee outcomes, so approach with your eyes wide open!

What to Expect from Treatment

The process typically involves a consultation, extraction of stem cells, lab processing, and injection into the affected area. The whole treatment time is normally from 1-3 days and if you’re travelling abroad you can complete the full process in 5-7 days.

In terms of recovery, there is no real lag time here, you’re pretty much back to day to day activities once you’re back!

Clinic Quality is Crucial

There’s a lot of fluff out there. Picking the right clinic is one of the most important decisions you have to make. Are they actually giving you Stem Cells? Have they treated your condition before? There’s so many things you have to take into consideration.

But we’ve done a lot of the legwork for you & can connect you with clinics we trust and we’ve vetted. Check them out here!

Is Stem Cell Therapy Right for You?

Stem cell therapy is changing the way we treat injuries & chronic conditions, offering new hope where traditional medicine falls short. Most clinics use mesenchymal stem cells (MSCs) because they can help repair damaged tissue and reduce inflammation. But like any medical treatment, it’s important to understand the science, the risks, and the options available to you

However, it’s important to do thorough research, consume as much of the content we have here to help decide if it’s for you. Or speak to us here! We’ll help you work out if it could be an option for you and the best clinics to go for!