Could be. Lot of things I had been taking. But this was over-the-top edema. Most people would have gone to the ER. My legs and feet were easily 25% larger than normal. I couldn't even sit cross-legged. I didn't realize just how bad it had gotten until it was gone. I've been taking the same brand Creatine for a while, but I have noticed the past few years that something with Creatine in general has changed. Optimum Nutrition used to be Creapure, but then they quietly dropped that label, switching to some generically-made monohydrate, while keeping the same price. It also picked up some kind of "static cling" these past two years. No other way I can describe it. No longer granular. More powdery. Doesn't taste like old creatine mono, either. I noticed the same change with this same brand I've been taking, which is supposed to be Creapure, but I have my suspicions they are trying to bamboozle their customers and did what Optimum did but didn't remove the Creapure mark. This most recent container has same characteristics... static, powdery, no taste.. whereas previous containers were identical to that first tub I bought from GNC back in the 90's. Old creatine mono is almost flavorless to me.. but it does have a very distinctive, mild taste. Could it be something toxic with this new tub? Maybe. I don't think I'm ever gonna know at this point. All I know is I was holding on to a ton of fluid, and that nasty bout of edema didn't seem to resolve until I just dropped everything.