"What is the difference between hemp derived and non-hemp CBD?"
This is a good question. The DEA's definition of a hemp based product is that it contains less than .03 per cent THC, regardless of the origin. So, the simple answer is that when isolated you can not tell the difference between them. Chemically, they are identical. However, the sourcing, manufacturing, and efficacy make things more complicated. Pro- cannabis CBD proponents state that using a full plant extract from the marijuana plant provides greater healing because of the entourage effect, meaning you are getting the full spectrum of cannabinoids as nature provides them - and they work better together than individually. They also posit that it takes so much concentrated CBD from hemp that heaving metals are concentrated into the hemp based CBD from the dirt. In short, you can get organic tested hemp based CBD; I have seen CBD isolate work the entourage effect notwithstanding. If employment drug testing, a desire to not get high, or a chronic disease is what ails you (as opposed to stage 4 cancer) starting with hemp based CBD is a safe and effective way to start. If things don't improve, then perhaps switch to cannabis based whole plant extract or tincture. .