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Guaifenesin and Upset Stomach: What Users Say

Brand names: Mucinex, Mucinex Maximum Strength, Humibid, Breonesin, Tussin Expectorant, Robafen, Family Meltus Chesty Coughs, Fenesin, Guaiatussin, Organ-1 NR, Scot-Tussin Expectorant, Guiatuss, Altarussin, Diabetic Tuss, Guiadrine G-1200, Xpect, Junior Meltus Chesty Coughs with Catarrh, Dristan Chesty Cough Guaiphenesin, Benadryl Chesty Forte, G Bid, Ganidin NR, Humibid Pediatric, Mucinex Children's Chest Congestion, Guaibid-LA, Aquamist, Amibid LA, Mucobid-LA, Guaifenex LA, Fenex-LA, Rompe Pecho EX, Guaifenesin LA, Humavent LA, Guiacough, GG 200 NR, Glytuss, Anti-Tuss, Diabetic Expectorant, Allfen Jr, Genatuss, Siltuss DAS, Gua-SR, Humigen LA, Altorant, Duratuss G, Robitussin Mucus + Chest Congestion, Guaifenex G, GG-Cen, Benylin E Calmylin Expectorant Siltussin DAS-NA Balminil Expectorant Drituss G Beechams Veno's for Kids Chesty Cough Junior Meltus Colour and Sugar Free Expectorant Help I Have Chest Congestion Bidex-400 Humibid E Fenesin IR Hill's Balsam Chesty Cough Beechams Veno's Expectorant Lemsip Cough Chesty Dristan Chesty Cough Mucinex for Kids Guaifen NR Buckley's Chest Congestion TabTussin 400 Siltussin DAS Diabetic Tussin Mucus Relief Refenesen Chest Congestion Relief Bronchoril Hytuss Mucaplex Tussin Mucus + Chest Congestion Air Power Diabetic Tussin Chest Congestion Giltuss EX Expectorant Giltuss Children's EX Expectorant …show all brand names

Upset stomach: mentioned by 6 users (2.0%)

Based on user experiences from 306 Guaifenesin reviews, the following table shows the most commonly mentioned side effects.

All user comments are moderated by Drugs.com. Each review is verified for relevance and screened for inappropriate content. Side effects are user-reported and not clinically verified.

dizziness 4.9%
nausea 4.9%
cough 3.9%
drowsiness 3.9%
pain 3.6%
vomiting 2.6%
diarrhea 2.3%
headaches 2.3%
insomnia 2.0%
upset stomach 2.0%

Reviews for Guaifenesin

Showing 6 reviews tagged with "upset stomach". Clear filters to view all 306 reviews.
Commonly mentioned side effects
  • nas...
  • Taken for less than 1 month
  • November 22, 2013

Guaifenesin for Bronchitis "Mucinex is great and it works well, but whatever you do, DO NOT take it on an empty stomach. I did this morning, and as the day went by, I kept feeling worse and worse. When I finally got the chance to eat something, my stomach was so upset that it just came right back up. Again, it's a great medication but eat something before taking it."

8 / 10
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  • dot...
  • April 24, 2013

For Bronchitis "Guaifenesin is great for my bronchitis. But, I have learned that whether I take the liquid or tablet, I must eat first. If I take this on an empty stomach, which is what I did about an hour ago, I have such a reaction it almost puts me on my knees. Luckily, within 15 minutes of realizing what was going on, I was able to get something to eat. The first reaction was almost 20 years ago with the liquid, I ended up in the ER. I didn't know what was wrong. Today I took a pill on an empty stomach, and my stomach began to cramp severely within a short time. This was a sinus/mucous relief tablet with guaifenesin. I'm okay now, but do not take guaifenesin on an empty stomach! You don't want to try it first. I'll keep taking it, but eating first."

10 / 10
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  • dma...
  • Taken for 1 to 6 months
  • June 6, 2021

For Fibromyalgia "I have been suffering with fibromyalgia for many years. Guaifenesin 2400 mg to 4800 mg a day loosens my muscles that are tight and painful. I'm able to breathe deeper with the relaxed muscles. My stomach isn't as irritated, and my skin isn't as irritated. My anxiety is lessened. I've also included Ribose powder 10 to 15 mg a day, and it helps with fatigue."

8 / 10
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11 Report

Frequently asked questions

  • Jes...
  • November 7, 2012

For Bronchitis "This medicine works wonders! I'd definitely give it a 10 had it not given me a bit of an upset stomach. I think I may have been taking too much. I will continue to take this medication anytime I feel it is needed. I get it at Walmart. Mucus doesn't stand a chance when it comes to guaifenesin!"

9 / 10
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14 Report
  • Jo7...
  • January 15, 2017

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

1 / 10
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21 Report
  • She...
  • February 25, 2018

Guaifenesin for Bronchitis "Made me worse. Stomach issues and did nothing for my cough and sinus drainage. Would not recommend."

1 / 10
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13 Report

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