The Commonwealth variant of Med-X is considerably larger than the Capital and Mojave Wasteland versions, likely making it easier to collect, due to past iterations being incredibly small. In addition to the size increase, the Commonwealth variant also has purple-tinted glass along the barrel of the syringe to improve its visibility.
Med-X is a clear, opiate-based analgesic most commonly used as a powerful painkiller. The drug had a notorious presence in the US Army, as seen in initiatives such as Operation: Blue Blood (Stealth suit Mk II) and the MP-47/A prototype medic power armor project. However, the Med-X seen in the Commonwealth today could not possibly be of Pre-War origin because the potency of its components would surely have expired already. Through this fact it is made apparent that the the organic parts of Med-X can still be produced, albeit to a greatly reduced degree. Still though, despite the far lower quantity of Med-X that presently exists the drug is seeing much more widespread use due to the new laws and cultures of the post-war Wasteland.