The short, clear answer is this: Glutathione should be taken for a minimum of 3 months, with an ideal duration of 36 months, depending on your skin goals, dosage, and individual response
These elevated levels reflect successful absorption and distribution of the vitamin into the bloodstream, where it can be utilized by tissues (source: National Institutes of Health)
At higher temperatures, its vapor pressure increases, meaning more of it will exist as a gas in the headspace of the vial rather than dissolved in the water where it needs to be to inhibit bacterial growth
Zhang D, Song S, Lin J, Ye T,Yang X,Jiang Q,Mi Y,Zhang M, Ge X,Shen Y,Du P,Shi Y, Zhang X, Li L, Zhang Y, Ding L, Liu J, Zhang
Other reports showed that ABCC1, ABCC11 and ABCG2 are highly over-expressed in subtypes of aggressive breast cancer and that increased expressions of ABCC1 and ABCC11 were significantly associated with shorter disease-free survival 68