...since it's a Chinese supplier you have to be careful with it's purity. Even my Chinese girlfriend doesn't trust this source. Hopefully Sara will start selling again because I'd like to try Lufenuron too.
Lufenuron is used in pesticides/fungicides for plants. Anything for sale on most of those places is going to be agricultural grade and may contain other substances or heavy metals, etc. I certainly wouldn't ingest it.
Although, I'd certainly look into a less expensive way to experiment with this protocol since we've all been spending WAY too much money trying to get our lives back, right?