People considering stem cell therapy to treat damaged tendons, torn ligaments, and other sports injuries want to know Is it safe?

While long-term studies are still needed, research does suggest stem cell therapy, when using a patient’s own cells without any manipulation and performed in a single sitting, is generally considered safe. 1 Andia I, Maffulli N. Biological Therapies in Regenerative Sports Medicine. Sports Med. 2016 The most common side effects are temporary swelling and pain. 2 Chahla J, Dean CS, Moatshe G, Pascual-garrido C, Serra cruz R, Laprade RF. Concentrated Bone Marrow Aspirate for the Treatment of Chondral Injuries and Osteoarthritis of the Knee: A Systematic Review of Outcomes. Orthop J Sports Med. 2016;4(1):2325967115625481. Stem cell injections carry the same risks as any other therapeutic injection, such as a small risk of infection.


Factors that can increase risk
A patient is at a higher risk of an unwanted reaction if the stem cells are:

  • Not the patient’s—though uncommon, stem cell therapy can involve stem cells manufactured in a lab or harvested from another person or animal. In the majority of cases, stem cells are collected from the patient, minimizing the risk of an unwanted reaction.
  • Cultured—taken from the patient and grown in the lab over time.
  • Mixed with other chemicals—additives thought to enhance stem cells’ therapeutic abilities may also add another risk factor.

In This Article:

Some research suggests that manufactured, foreign, or manipulated stem cells may elevate the risk of tumors. 3 Herberts CA, Kwa MS, Hermsen HP. Risk factors in the development of stem cell therapy. J Transl Med. 2011;9:29. For this reason, the FDA limits how much stem cells can be manipulated.

As with most regenerative medicine treatments, research is ongoing and FDA regulations are subject to change.

See Regenerative Medicine for Sports Injuries


Questions to Ask Your Doctor

People considering stem cell therapy are advised to ask doctors questions, including:

  • What is your experience using stem cell therapy?
  • How will my stem cells be harvested?
  • If using an injection, will medical imaging be used to ensure accuracy?
  • How do people with sports injuries like mine usually respond to treatment?
  • What are the potential risks and complications?

See Choosing a PRP Therapy Doctor

Both doctors and patients can benefit from having a frank conversation and setting reasonable expectations.