A multibillion-dollar industry is growing around the idea that the body’s own cells can help repair what medicine still struggles to treat. However, as stem cell clinics continue to expand, the gap between what is being promised and what science can currently prove is also widening.
In 2010, Greg Novacheck, a former professional athlete, suffered a catastrophic hamstring injury. His biceps femoris, on the back of his thigh, tore completely in half, with a 10-centimeter retraction. The muscle separated into two distinct pieces, leaving a clearly visible and palpable divot. Multiple surgeons told him that surgery was unlikely to succeed.
It was then that he was introduced to a south Florida company specializing in stem cell processing. Sixteen days after receiving stem cell therapy combined with platelet-rich plasma—a treatment derived from a patient’s own blood that concentrates healing factors—the two halves of his muscle had reconnected, as seen in MRI scans after treatment, Novacheck told The Epoch Times.
“For me, it was life-changing,” he said. “But I’m also very aware that my outcome may not be typical.”
Although some stem cell therapies are well-established, much of the recent growth is happening in private clinics, where treatments are marketed for joint pain, injuries, and other chronic conditions, sometimes ahead of strong evidence.
What Stem Cells Are—and Which Ones Doctors Use
Stem cells can transform into different types of cells, through a process called cellular differentiation, and help repair or replace damaged tissues. In medicine, they are used primarily in treatments such as bone marrow transplants for blood cancers and immune disorders.
Researchers are also studying stem cells for a wide range of conditions, including neurological diseases, autoimmune disorders, and orthopedic injuries—but most of these applications remain experimental.
Stem cells used in regenerative medicine generally fall into four categories, although they continue to evolve as research advances.
- Adult: The most commonly used stem cells in clinical practice today. Major types of adult stem cells include hematopoietic stem cells, used in bone marrow transplants for blood and immune disorders, and mesenchymal stem cells, which are taken from bone marrow or fat tissue. They can develop into bone, cartilage, fat, and tendon. Mesenchymal stem cells are the type most commonly used in private orthopedic clinics.
- Perinatal: Found in the umbilical cord, placenta, and other birth tissues that are usually discarded after delivery. Cord blood stem cells have long been used to treat blood and immune disorders, while other cells from these tissues are being studied for regenerative and anti-inflammatory therapies.
- Embryonic: Derived from early-stage embryos and largely confined to laboratory research, embryonic stem cells are not yet used in clinical treatments and remain ethically debated because obtaining them requires the destruction of embryos.
- Induced Pluripotent: Adult cells reprogrammed to behave like embryonic cells. Induced pluripotent stem cells are being actively developed for conditions such as degenerative diseases and heart conditions, although most uses are still in research or clinical trial phases.
What Clinical Trials Show So Far
Most stem cell treatments are not approved by the Food and Drug Administration (FDA), except for hematopoietic stem cells from umbilical cords used to treat immune or blood disorders. Many private stem cell clinics operate without FDA oversight, because many of these procedures use the patient’s own cells and are regulated as medical practices rather than FDA-approved drugs, placing them in a regulatory gray area.
Hematopoietic stem cell transplants for blood cancers and disorders are well-established and FDA-supported. Nearly everything else—including the orthopedic and joint treatments being widely marketed—is still in various stages of research.
Stem cell injections may offer small short-term improvements in pain and knee function for people with knee osteoarthritis, one of the most common conditions treated at private clinics, according to a 2025 meta-analysis of 25 clinical trials involving 1,341 patients. However, stronger evidence is still needed to confirm their long-term benefits and safety.
Meanwhile, an earlier 2020 review of nine clinical trials found that stem cell therapy appeared more effective than traditional conservative treatments, reducing pain and improving knee function over 24 months without adding significant side effects—but that study involved just 339 patients, a relatively small pool.
For neurodegenerative diseases, including Alzheimer’s, Parkinson’s, amyotrophic lateral sclerosis, multiple sclerosis, and spinal cord injuries, stem cell research is gradually moving from animal studies to early human trials.
“Even with stem cell therapy, tissue repair follows natural timelines,” Christian Drapeau, a stem cell scientist, researcher, and author, told The Epoch Times. “Factors like age, health, and injury severity play a big role in outcomes.”
Most of the “tissue regeneration” seen in preclinical models does not translate into the same level of structural repair in human patients, Drapeau said.
“Animal studies often show new tissue, axonal regrowth, or cartilage-like repair, but these models are tightly controlled, with standardized injuries and a biological environment more favorable than in older humans with chronic disease,” he said.
In clinical settings, he noted, the main benefits of mesenchymal stem cells are usually functional rather than structural.
“Patients may see reduced pain, improved mobility, or decreased inflammation, but full replacement of damaged tissue is rare,” he said.
Dr. Pamela Mehta, a board-certified orthopedic surgeon and founder of Resilience Orthopedics, echoed that view.
“In my experience, patients with early to moderate osteoarthritis and chronic degenerative tendon injuries respond best,” Mehta told The Epoch Times. “These are conditions driven by inflammation and poor healing. Stem cells are less reliable for advanced bone-on-bone arthritis or large, full-thickness tendon tears, which usually require surgical solutions.”
How the Treatment Actually Works
A common misconception is that mesenchymal stem cells directly transform into new tissue. Dr. David Woznica, a sports medicine physician at Woz Wellness, explained it differently.
“In reality, most of their benefit comes from releasing signaling proteins and exosomes that reduce inflammation and promote tissue growth,” he told The Epoch Times.
A small subset of cells—called muse cells—can transform into different tissue types, but they make up only a tiny fraction of what’s administered. Muse cells are extremely rare and difficult to isolate and expand in large numbers, and their clinical use is still in early research, so most therapies rely on more readily available and better-studied stem cell types instead.
Private clinics also frequently combine stem cell injections with complementary treatments such as platelet-rich plasma, hyaluronic acid, structured rehabilitation, and oxygen therapy.
“This approach may explain why clinic outcomes oftentimes lead to far superior results than what has been reported in tightly controlled trials,” Drapeau said.
Risks, Unknowns, and Long-Term Safety
Mesenchymal stem cell therapy appears to be safe when performed under appropriate standards, with only minor short-term side effects such as fever or pain.
However, unsafe or unregulated stem cell treatments may lead to tumor formation, immune reactions, infection, or other complications, especially when protocols are not properly followed.
“In case of clinical applications for orthopedic conditions, the most common side effects are mild and temporary, like soreness, swelling, or an inflammatory flare,” Mehta said. “Infection or bleeding are rare but possible, as with any injection.”
Experts emphasize that long-term safety data are still limited, particularly for newer or experimental uses.
Novacheck’s recovery is the kind of story that drives patients toward private clinics. Individual outcomes, however dramatic, are not a substitute for controlled clinical evidence, and biology varies significantly from patient to patient.
“Biology and disease stage matter more than marketing claims,” Mehta said. “Earlier disease, better tissue quality, and overall health tend to produce better results.”
What Patients Should Know Before Signing Up
When choosing a stem cell clinic, experts recommend the following when evaluating a stem cell clinic:
- Choose Physician-Led Clinics With Expertise: Look for practices led by doctors, such as orthopedic specialists for joint conditions, that provide clear explanations of the stem cell products and offer realistic counseling. Be cautious of anyone promising to “cure” arthritis or fully regenerate cartilage.
- Watch for Red Flags in Claims: The stem cell marketplace includes clinics that exaggerate results. Be wary of guaranteed outcomes, lack of clear information about cell source, processing methods, regulatory compliance, no discussion of risks or limitations, and pressure to pay large upfront fees without proper consent documentation.
- Be Patient With Results: Healing takes time. Most treatments require multiple sessions, and soreness or temporary worsening may occur. Tissue regeneration can take months, even under ideal conditions.
What matters in practice is whether a clinic follows clear, standardized protocols, uses high-quality, well-characterized cell sources, and can demonstrate consistent results backed by reliable patient follow-up data, Drapeau said.
“This is what separates more credible practices from unproven treatments,” he said.