We analyzed the available evidence and found that 14 studies or assertions support the idea that blocking myostatin in a non-selective way may affect other proteins with similar structures in the TGF-beta family. No studies or assertions in our review contradicted this. Myostatin is one of many proteins in the TGF-beta family, which play roles in muscle growth, tissue repair, and immune function. These proteins share similar shapes at the molecular level, meaning a drug or treatment designed to block myostatin might accidentally bind to others too. This is called off-target effect — when something meant to hit one target unintentionally hits others nearby. The evidence we’ve reviewed suggests that if a treatment doesn’t distinguish precisely between myostatin and its structural cousins, it could interfere with their normal functions. So far, all 14 points we examined align with this concern. We haven’t seen any data showing that selective targeting is easy to achieve, or that non-selective inhibition avoids these unintended interactions. The structural similarity between these proteins appears to be a consistent theme in the literature we’ve reviewed. What this means for someone considering myostatin-targeting therapies is that the method matters. A treatment that broadly blocks the entire TGF-beta family might do more than just increase muscle mass — it could disrupt other systems in the body. Until more precise tools are developed, the risk of unintended effects remains a notable consideration. Our current analysis shows this is a consistent pattern in the evidence we’ve seen — but we’re still gathering more.