Bone marrow aspirate concentrate (BMAC) and adipose-derived preparations such as microfragmented adipose tissue (MFAT) and stromal vascular fraction (SVF) are increasingly offered as ‘stem cell’ treatments, yet they differ substantially in composition, processing and regulatory status. This talk will clarify what these products actually contain, how they are thought to act, and how UK regulation distinguishes minimally manipulated tissue procedures from advanced therapy medicinal products. It will critically review the current clinical evidence, mainly in knee osteoarthritis, separating symptomatic and functional improvement from claims of structural regeneration, and will illustrate intraosseous BMAC application for bone marrow lesions with a clinical case including MRI follow-up. Delegates will leave with a practical, evidence-based framework for patient selection, counselling and positioning these therapies within sport and exercise medicine practice.