Bests & Worsts Reviews from Amazon

I've used this brand for several years, but have noticed a sharp decline in the quality lately. I decided to stop buying after having 4 occurrences of scents being compromised in some way. Issues included: 1. Oils spoiling within a few months. Either going 'flat' or completely rancid/sour. Perhaps stock is not being rotated to account for shelf life 2. Oils not feeling as pure. As I've replenished scents, the new one is noticeably less potent and viscosity is different. 3. I'm speculating here - seems these are 'oil blends' being marketed as 'pure.' e.g. like jojoba/essential combos you see from other brands