We now offer Resp-Aid and L-Glutathione plus in a combo to save patients a few dollars over ordering them individually. I use the L-Glutathione plus on a regular basis and the Resp-Aid when I feel not quite up to par. Resp-Aid is not meant to be a daily nebulizing treatment like the L-Glutathione plus. My advice is to always keep some on hand just in case. It has unlimited shelf life.