Conclusion: The results of this review have to be interpreted with caution because the number of studies in each category of cough preparations was small. Availability, dosing and duration of use of over-the-counter cough medicines vary significantly in different countries. Many studies were poorly reported making assessment of risk of bias difficult and studies were also very different from each other, making evaluation of overall efficacy difficult. There is no good evidence for or against the effectiveness of OTC medicines in acute cough. This should be taken into account when considering prescribing a
Guaifenesin side effects
Across 11 first-hand reports, people mentioned a side effect 9 times (about 82 per 100 reports). The most common: kidney stones, nausea, stomach issues. User reports show what people notice — they can't tell you whether Guaifenesin is safe for you.
Reported side effects
kidney stones3
nausea2
stomach issues1
stomach discomfort1
throat irritation1
voice hoarseness1
In their own words
“bronkaid contains 400mg of guaifenesin per 25 mg of ephedrine. At my peak i'd like to be taking 75 mg a day of ephedrine thats 1.2g of guaifenesin a day that I really don't need or want.”
“the Guaifenesin is fucking up my throat at something severe, and making my voice sound like an 80-year old chain smoker”
Is Guaifenesin safe? What the research covers
AResearch: Strong6 meta-analyses · 23 randomized trials on PubMed
Cochrane Database Syst Rev · 2014
Over-the-counter (OTC) medications for acute cough in children and adults in community settings