I asked Chatbot about this and while there is some evidence that Mullein, the product the part of the herb that affects lung, unless you know the details on where and how it was manufactured, it could be useless. Apparently it is mainly marketed to smokers and others as a lung detox. Chatbot warns that the certificate of analysis (COA) should be checked, if they have one. I compared it to Guaifenesin which I started a month ago and was advised it is a wiser choice.