Guaifenesin and Vomiting: What Users Say

• Anonymous
• November 7, 2011

Guaifenesin for Cough "About an hour and a half after taking one Mucinex DM, I developed severe dizziness, drowsiness, bad intestinal cramps, vomiting, and diarrhea that recurred over a period of 2 hours. It was the only medication in my system."

• Tea...
• Taken for 1 to 2 years
• December 9, 2018

For Cough "Every time I have a cold, I get these very bad coughs. I have very 'violent' coughs where they come in episodes. It's ridiculous. I took this and yes, it works, but for me, it literally calms my coughs down, then collects all my mucus together, and then I literally start to vomit. But the vomit is all mucus and phlegm. It's disgusting, but it works. I just hate how it collects it all and wait for that moment when you don't want it to happen. Then it happens in the middle of class or work."

• Cha...
• Taken for less than 1 month
• August 31, 2018

For Cough "I used guaifenesin for mucus relief with a cough. I drank a full bottle of water with it and 30 minutes later, ate supper. At 12:30, I woke up with vomiting and severe diarrhea. Blood pressure went sky high (from a normal low). Headache and dizziness. I couldn’t eat for 2 1/2 days because of the nausea. Blood pressure went back to normal after 24 hours. I have used other cold medicines, and every one would make me at least slightly nauseous. I didn’t know they all contained this ingredient. This seems to be abnormal for this medicine, so I think I may be allergic."

• Pup...
• Taken for less than 1 month
• May 16, 2016

Guaifenesin for Cough "I took this attempting to get rid of a cough and chest congestion. I am a 105 lb 30-year-old female. I took one pill yesterday and felt a little better. That was a half dose, so today I tried 2 pills, a full dose. After feeling nauseous for several hours, I finally threw up several times and am feeling much better. I will not be taking it again and would rather allow the congestion to run its course."

• CJ ...
• Taken for less than 1 month
• December 14, 2021

For Cough "Yoo, I know everybody is different, but this stuff acted is so awful for me. I was unable to sleep because of post-nasal drip and a cough, so I decided to take one dose of the children's version of guaifenesin. After one hour, I suddenly got extremely dizzy and was violently vomiting. I think that's over now that it's out of my system, hopefully, but lord knows I will never ever take this stuff again. I felt like I was going to die. The irony is I took this to help with a sore throat from the post-nasal drip, but now my throat hurts even worse than before because of the vomiting. I hope this reaction isn't common for people. I wouldn't wish my experience on anyone."

• Anonymous
• Taken for less than 1 month
• January 6, 2025

Guaifenesin for Cough "I highly recommend drinking large amounts of water with this medication. I was not aware to do so because it was nowhere to be found on the label, and it resulted in vomiting and the runs. After hours of this and speaking with a nurse, I was able to get it under control. Will not ever take again."

• Anonymous
• October 20, 2014

Guaifenesin for Cough "I've been up for hours, throwing up and having diarrhea after taking this."

• mrs...
• Taken for less than 1 month
• May 4, 2022

Guaifenesin for Bronchitis "Took Mucinex once yesterday and was fine but a bit nauseous from it, even with food, today the second dose made me throw up and feel absolutely awful within an hour. Would not recommend."