Mucinex D and Dry Mouth: What Users Say

• Kma...
• February 29, 2016

For Cough and Nasal Congestion "I took Mucinex D before bed because my sinuses were congested and I could feel mucus in my lungs, making it hard to breathe. Shortly after taking the medication, everything loosened up, my nose ran, but I could breathe. Unfortunately, it's now 6 AM, and I haven't slept a wink and have had a rapid heart rate and anxiety. I have a headache and am too jittery to sleep. I did feel slightly nauseous after I took the pill and very dry mouth now."

• Amb...
• September 20, 2016

For Cough and Nasal Congestion "Took this with food. Made me feel very lethargic and jittery at the same time. My appetite is gone. My congestion is cleared, but I can't wait for this medication to wear off. My heart rate speeds up as well. Dry mouth, yuck."

• Hel...
• March 31, 2016

For Cough and Nasal Congestion "It dehydrates you like crazy, and I could not drink enough liquids. My throat got so dry it caused me to cough uncontrollably. For the past 3 nights, I could not sleep... Even took 10 mg of Ambien, which usually knocks me out cold... But it didn't work. I just found this site and learned that my insomnia is caused by Mucinex D. Not worth the lack of sleep!"

• Mom...
• March 17, 2017

For Cough and Nasal Congestion "Followed directions & took 2x Mucinex D 1200mg at 9:30 PM. Decided to pick this up after being sick & out of work for 5 days. I was really tired & dozed off at 11:30 PM. It's 3:30 AM, I can't sleep... I'm wide awake with an extra dry mouth, swelling of the tongue, slight nausea, tossing & turning (anxiety?), tingling/weakness in my arms. Most of my cold symptoms are gone (amazingly!), but I can't shake these side effects right now & am wondering exactly when I'll be able to sleep! I would NOT recommend taking this at nighttime, & if you are going to try this stuff to start with just 1 pill."

• Anonymous
• October 9, 2011

For Cough and Nasal Congestion "I took one Mucinex DM at 11 AM, and coughing and mucus flow was reduced significantly, although accompanied by dry mouth. Yesterday at noon, I would have given it 10/10. However, I took one capsule at 8 PM and had severe insomnia and could not fall asleep until 8 the next morning."

• SSF...
• Taken for less than 1 month
• February 20, 2025

For Cough and Nasal Congestion "I highly recommend Mucinex D. First of all, I am not tolerant of many cold/allergy medicines. I was prescribed Mucinex D (2 pills every 12 hours) for my chest and nasal congestion. It seems everything I take affects me with anxiety, drowsiness, dry mouth, nausea, or something. So, to be safe, I took only 1 tablet to start. Within 1/2 hour, my cold symptoms were so much better, and I had no side effects from the pill. Then, 6 hours later, my cold symptoms started getting bad again. So, I took 1 more at 6 hours. Long story short, I have been taking Mucinex D for 3 days. But my schedule is 1 tablet every 6 hours, instead of 2 every 12 hours (still at the limit of 4 in 24 hours). I have had no trouble sleeping (except for the cough and nasal stuff). I am not sleepy, or anxious, or anything. In fact, I feel great. It does seem to be an appetite suppressant too...bonus! I am so glad I took the chance of making my own dosing schedule. It works!"

• Anonymous
• January 26, 2009

For Cough and Nasal Congestion "This medicine worked to relieve my nasal congestion, but it gave me severe insomnia. I stayed up for an entire night. I also experienced dry mouth."

• Anonymous
• January 4, 2012

For Cough and Nasal Congestion "Definitely works great for my sinus congestion, but, like others, experienced insomnia and dry mouth. Took one pill at 6:00 in the evening. Probably better to take in the morning."