It is used as an expectorant, alone or in association with other products. Proofs on its effectiveness are sparse. In some instances, preparations of Guaifenesin may contain alcohol as excipient with a concentration as high as 5%. At latest update, relevant published data on excretion into breast milk were not found. Until more information on this medication is available, other option known to be safer would be recommended, mostly in the post-natal period or in cases of prematurity. If used while breastfeeding, a moderate use with the lowest dose as possible and avoiding those preparations with alcoholic excipient, should be preferred. Because effectiveness is poor and likelihood of side effects does exist, especially in multi-association, the US Agency for Drug Administration (FDA) is currently doing efforts for discontinuation of this and others at-the-counter products, that are formulated for cough relief (Guaifenesin, Dextromethorphan, Phenylephrine, Pseudoephedrine, Brompheniramine, etc.)