I was using Body Fortress which in hindsight is probably garbage. I probably saw it at the store once and then kept purchasing due it being available everywhere (and cheap!). I ended up ordering the smaller size of this one to try. Looks like it's pretty clean and unadulterated, and apparently undenatured. Should be here today so I'll report back my initial thoughts. I'll probably try a few of the other recommendations posted, but was kind of surprised at the myriad of ingredients in a lot of these products. Thanks for the recommendations!