New injectable products appear in sport and exercise medicine (SEM) faster than any page can list them, and an athlete will usually hear about one long before a clinician does. Rather than attempting a catalogue that will date, this page does two things: it sets out a method for assessing any unfamiliar injectable, and it applies that method to the categories currently being marketed, including cell-derived vesicles such as exosomes, birth tissue and amniotic products, and protein-concentrate preparations. The general orthobiologics regulatory framework and the position on platelet-rich plasma are covered in the related material. What follows concentrates on what is genuinely new, what is simply relabelled, and how to answer the athlete who arrives with a brochure.
How should an unfamiliar injectable be assessed?
Five questions cover almost everything. What is actually in it, in terms of cells, proteins, vesicles or synthetic components, and is that stated in a way that could be verified? How was it processed, since the degree of manipulation determines both what the product is and how it is regulated? Is it therefore a medicine, a human tissue product, a medical device, or something being sold outside all of those categories? What human trial evidence exists for this specific preparation in this specific condition, as distinct from evidence for a related product or for the underlying biological concept? And what is its anti-doping status, which for a competing athlete may be the decisive question. A product that cannot answer the first question cannot be assessed at all, and a preparation whose contents cannot be established cannot be assumed to be permitted or safe.
Five questions assess any unfamiliar injectable: its contents, how it was processed, its regulatory status, the trial evidence for that specific preparation in that specific condition, and its anti-doping position.
Two patterns recur and are worth naming. The first is category drift, in which a product is described using the vocabulary of a regulated therapy without meeting its definition: the words regenerative, stem cell and biologic all get applied to preparations that contain very few of the relevant cells, or none. The second is evidence transfer, in which laboratory findings or animal data are presented as though they were clinical evidence, or a trial of one preparation is used to support a different one from another manufacturer. Both are marketing techniques rather than clinical arguments, and both are easier to spot once you are looking for them. It is also worth remembering that novelty and cost tend to travel together while evidence lags behind, so the newest and most expensive option in a clinic is rarely the best supported.
What is currently being marketed?
Cell-derived vesicles, usually marketed as exosomes, are the most prominent current category. These are small membrane-bound particles released by cells, carrying proteins and nucleic acids, and the proposal is that they deliver the signalling benefits attributed to cell therapy without the cells themselves. The biological rationale is real and the clinical evidence in musculoskeletal conditions is minimal, consisting largely of laboratory work, animal models and small uncontrolled series. Regulation is unforgiving here: a product of this kind is likely to fall within the medicines framework, and preparations sold outside that framework are operating outside the intended controls. The anti-doping position also changed recently and matters, because the addition of cell components to the gene and cell doping method brings vesicle products within scope where they have performance-enhancing potential, so an athlete should not be told these are outside anti-doping rules.
The three categories currently marketed are cell-derived vesicles such as exosomes, birth tissue and amniotic products, and blood-derived protein concentrates. All share a plausible mechanism with a small, low-certainty clinical literature.
Birth tissue and amniotic products, including amniotic membrane and umbilical cord derived preparations, are the second group. They are marketed for their growth factor and matrix content, and an important point is that commercially processed products of this kind typically contain few or no living cells, so describing them as stem cell treatments is inaccurate. They are also allogeneic rather than autologous, which introduces donor screening and traceability requirements and takes them into human tissue and medicines territory. Protein-concentrate preparations, produced by further processing blood to concentrate anti-inflammatory proteins such as interleukin-1 receptor antagonist and alpha-2-macroglobulin, form a third group; the concept overlaps closely with conditioned serum products, and the evidence remains limited and largely industry-generated. Across all three groups the honest summary is the same: a plausible mechanism, a small and low-certainty clinical literature, significant cost, and a regulatory position that is frequently misrepresented. None of them is established treatment, and none should displace loading, weight management, analgesia and the other measures that do have evidence.
Exam Tips
•Assess any unfamiliar injectable by five questions: contents, processing, regulatory category, trial evidence for that specific preparation and condition, and anti-doping status.
•Watch for category drift, where marketing borrows the vocabulary of regulated therapies, and evidence transfer, where laboratory or animal data or a different product's trial is presented as clinical evidence.
•Exosomes are cell-derived vesicles carrying proteins and nucleic acids; the rationale is plausible but musculoskeletal clinical evidence is minimal, and they are likely to fall within the medicines framework.
•The addition of cell components to the gene and cell doping prohibited method brings vesicle preparations within anti-doping scope where they have performance-enhancing potential.
•Commercially processed birth tissue and amniotic products typically contain few or no living cells, so calling them stem cell treatments is inaccurate; they are also allogeneic, with donor screening and traceability requirements.
•Protein-concentrate preparations concentrate anti-inflammatory proteins such as interleukin-1 receptor antagonist and alpha-2-macroglobulin, with limited and largely industry-generated evidence.