Guaifenesin and Dizziness: What Users Say

• mel...
• February 23, 2014

Mucinex (guaifenesin) for Bronchitis "Took this medication for a chest cough before I went to bed. Woke up in the night with severe nausea and felt dizzy. Tried it again a week later and the same happened. I know other people who swear by it."

• Anonymous
• November 7, 2011

Mucinex (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."

• Jes...
• April 10, 2017

Mucinex (guaifenesin) for Bronchitis "I'm not sure Mucinex works. I know it kept me wide awake. It was hard for me to sleep. When I was awake, I felt like my balance was off, so I felt dizzy. I couldn't go down spiral steps. I would not recommend it."

• Nic...
• Taken for less than 1 month
• April 3, 2018

For Bronchitis "For everyone that suffers from allergies, I highly recommend this product: Mucinex DM 1200 mg guaifenesin. I'm using the 12-hour extended-release tablets, I've had allergies for over 10 years, and nothing really worked. I felt dizzy and nauseous at times, but then as my body adjusted to it, it cleared my ears of gunk. Whenever a headache comes on, drink water. I'm happy to share this because I've suffered a lot and was not enjoying quality of life. Please do try it. God bless."

• DRL...
• August 27, 2015

For Bronchitis "I am on my second bout of pneumonia. The constant coughing is painful. I bought this drug OTC, and it is helping a lot. I feel a bit dizzy, but I will take dizzy over that constant hacking cough any day. I got this because it only has the 'mucus' drug, without the extra junk in Mucinex I don't need. The best part? For 15 tablets, it cost only 88 cents!"

• k9o...
• Taken for 1 to 6 months
• August 9, 2015

For Cough "I have been suffering from a severe sinus infection for 6 weeks. Antibiotics twice, 3 trips to the doctor. When I was at my sickest, I was using Mucinex D, and it may have helped some. I felt so bad then I don't know that I would have noticed side effects. But weeks later, I was still having so much thick drainage and lightheadedness in my throat that my doctor told me to switch to the Mucinex (plain), thinking it was the pseudoephedrine that was causing the vertigo. My vertigo worsened, and I never even thought of the medication being the cause because the doctor had said I would be fine without the pseudoephedrine in it. I went to the ER when my vertigo became alarming. All tests negative. After all that, I found I am allergic to guaifenesin."

• 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."

• Kwe...
• Taken for less than 1 month
• October 16, 2016

For Cough "Not long after taking my first dose of extra-strength Benylin for a persistent cold/respiratory infection, I became so dizzy I couldn't stand up and had to lie down. I closed my eyes and nodded off and woke up a while later feeling a little woozy but not dizzy. My head hurt the rest of the day. It did seem to help bring up phlegm that afternoon. I think I would take a half dose next time."

• Kwe...
• Taken for less than 1 month
• October 16, 2016

For Cough "Not long after taking my first dose of extra-strength Benylin for a persistent cold/respiratory infection, I became so dizzy I couldn't stand up and had to lie down. I closed my eyes and nodded off and woke up a while later feeling a little woozy but not dizzy. My head hurt the rest of the day. It did seem to help bring up phlegm that afternoon. I think I would take a half dose next time."

• 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."

• Rya...
• October 28, 2019

For Cough "A doctor told me to take this med, guaifenesin, for my upper respiratory infection, and my goodness, did it make me sick. I'm nauseous, dizzy, and just really nervous ... I think I am going to go back to my doc and break his nose."

• Sup...
• May 19, 2017

Mucinex (guaifenesin) for Cough "I took one, and I feel like I'm high. I am so dizzy I can't see straight, I feel like I'm floating. There is no way I am taking this again."

• Jo7...
• January 15, 2017

Mucinex (guaifenesin) for Cough "Gave me diarrhea, dizziness, nausea, stomach cramps, and even some numbness in tongue/face. Worse than the cough. Never again."

• LG1...
• January 28, 2013

For Cough "Worked wonders for helping upper airway congestion! However, extreme disturbing dreams felt like I was going crazy! Dizzy and scatterbrained, this was about 10 hours after taking 1."