D-mannose + Dextromethorphan HBr, Guaifenesin
Dextromethorphan HBr, Guaifenesin brand names: Vicks Formula 44E Cough & Chest Congestion Relief, Pediatric Vicks Formula 44e Cough & Chest Congesti.
We found no known interaction between D-mannose and Dextromethorphan HBr, Guaifenesin in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.
D-mannose and Dextromethorphan HBr, Guaifenesin
We checked these two against our interaction database. Here is what we found.
No Known Interaction Found
We did not find a documented interaction between Dextromethorphan HBr, Guaifenesin and D-mannose in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.
Worth understanding: our licensed dataset holds no drug-interaction record for D-mannose at all — not against Dextromethorphan HBr, Guaifenesin, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.
If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.
Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.
D-mannose safety at a glance
Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
See Every Supplement That Interacts With Dextromethorphan HBr, Guaifenesin
This page covers D-mannose only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Dextromethorphan HBr, Guaifenesin page lists 171 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), Grapefruit (major), Lithium (major), St. John's Wort (major) and 1,3-dmaa (moderate).
By severity: 4 major · 125 moderate · 42 minor.
From our pharmacist’s overview on the Dextromethorphan HBr, Guaifenesin page
“A bad cough tends to hit when supplements are already on the counter, and anyone reaching for Vicks Formula 44E (dextromethorphan HBr and guaifenesin) should treat this list with real care, since 4 of its 171 entries carry a major rating. Two themes dominate.”
Reviewed by 2 · Jul 18, 2026
Where D-mannose and Dextromethorphan HBr, Guaifenesin Sit Against Everything Else
Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.
#531 of 1,452 supplements looked up here in the last 7 days
#1,019 of 2,830 medications looked up here in the last 7 days
Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.
Where does our data come from?
- Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
- Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every D-mannose reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The D-mannose and Dextromethorphan HBr, Guaifenesin records this page draws on were last updated July 10, 2026.
- What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
About D-mannose
What is D-mannose?
- Preventing urinary tract infections (UTIs)
- Treating mild UTIs
- Urinary tract health
- Carbohydrate-deficient glycoprotein syndrome (a rare genetic condition)
D-mannose is a natural sugar most often used to help prevent urinary tract infections, especially those caused by E. coli. Early research is promising for prevention, but the evidence is still limited and it should not replace antibiotics for an active infection. Talk to your pharmacist or doctor before using it, particularly if you are pregnant, breastfeeding, or have diabetes.
Simple sugar (monosaccharide) derived from plants such as cranberries, apples, and other fruits and vegetables · Capsules, tablets, powder; often combined with cranberry
An interaction check asks whether these two react with each other — it does not ask whether D-mannose is a good idea for someone in your situation. Here is what our D-mannose record says about it on its own.
D-mannose: dosing
There is no official, standardized dose of D-mannose, and the amounts used in research have varied. Do not use D-mannose in place of prescribed antibiotics for an active infection.
From our D-mannose monograph — the full record covers uses, side effects and every documented interaction.
About Dextromethorphan HBr, Guaifenesin
Most-Reported Side Effects for Dextromethorphan HBr, Guaifenesin
From FAERS, the FDA’s public side-effect reporting system (1,675 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.
Other Drugs & D-mannose
Browse every other medication we’ve checked against D-mannose — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
No interaction 2,829 drugs checked — show the list
We also checked D-mannose against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Sertraline ›
- Testosterone ›
- Losartan Potassium ›
- Ivermectin ›
- Metoprolol ›
- Aspirin ›
- Rivaroxaban ›
- Rosuvastatin ›
- Escitalopram ›
- Acetaminophen ›
- Tadalafil ›
- Clopidogrel ›
- Abemaciclib ›
- Atorvastatin ›
- Docusate ›
- Hydroxyurea ›
- Valacyclovir ›
- Ibuprofen ›
- Methamphetamine ›
- Sumatriptan ›
- Semaglutide ›
- Tirzepatide ›
- Warfarin Sodium ›
- Prednisone ›
- Propranolol ›
- Lisdexamfetamine ›
- Metformin ›
- Bupropion ›
- Amoxicillin ›
- Lisinopril ›
- Bendamustine ›
- Acyclovir ›
- Amitriptyline ›
- Methotrexate ›
- Doxycycline ›
- Fluoxetine ›
- Amphetamine ›
- Lamotrigine ›
- Acetaminophen, Codeine ›
- Pregabalin ›
- Gabapentin ›
- Azithromycin ›
- Dextroamphetamine ›
- Isotretinoin ›
- Methylene Blue ›
- Clonazepam ›
- Omeprazole ›
- Amlodipine Besylate ›
- Quetiapine ›
- Duloxetine ›
- Letrozole ›
- Naproxen ›
- Buspirone ›
- Citalopram ›
- Ciprofloxacin ›
Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full D-mannose list.
D-mannose References
The 6 references that drive our D-mannose monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.
- Westphal V, Kjaergaard S, Davis JA, et al. Genetic and metabolic analysis of the first adult with congenital disorder of glycosylation type Ib: long-term outcome and effects of mannose supplementation. Mol Genet Metab 2001;73:77-85. PubMed
- Kranjcec B, Papes D, Altarac S. D-mannose powder for prophylaxis of recurrent urinary tract infections in women: a randomized clinical trial. World J Urol. 2014 Feb;32(1):79-84.
- de Lonlay P, Seta N. The clinical spectrum of phosphomannose isomerase deficiency, with an evaluation of mannose treatment for CDG-Ib. Biochim Biophys Acta. 2009;1792(9):841-3. PubMed
- Harms HK, Zimmer KP, Kurnik K, Bertele-Harms RM, Weidinger S, Reiter K. Oral mannose therapy persistently corrects the severe clinical symptoms and biochemical abnormalities of phosphomannose isomerase deficiency. Acta Paediatr. 2002;91(10):1065-72. DOI
- . Damen G, de Klerk H, Huijmans J, den Hollander J, Sinaasappel M. Gastrointestinal and other clinical manifestations in 17 children with congenital disorders of glycosylation type Ia, Ib, and Ic. J Pediatr Gastroenterol Nutr. 2004;38(3):282-7. DOI
- Lenger SM, Bradley MS, Thomas DA, Bertolet MH, Lowder JL, Sutcliffe S. D-mannose vs other agents for recurrent urinary tract infection prevention in adult women: a systematic review and meta-analysis. Am J Obstet Gynecol. 2020;223(2):265.e1-265.e13. PubMed
Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
Taking D-mannose and Dextromethorphan HBr, Guaifenesin Together: Common Questions
Is it safe to take D-mannose with Dextromethorphan HBr, Guaifenesin?
Does Dextromethorphan HBr, Guaifenesin interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.