@poodledoc I think it was the store brand from The Vitamin Shoppe. I didn't have any adverse reactions to it at 600 mg per day. I'm glad it is helping you. I have had problems clearing my lungs because of physical issues due to thoracic outlet syndrome, so my ribs don't expand properly, and it lets phlegm stagnate which leads to infections. I'm working on that in physical therapy, controlling allergies, and using good surgical masks when I will be exposed to dust or irritants, and all of that along with some generic Mucinex now and then is working. I think my best improvement is coming from progress in physical therapy and using myofascial release to reduce the pressure and get muscles around the chest moving better. I don't buy anything edible from China, at least according to labeling. Thanks for your recommendation.