Drug & supplement interaction

Glucomannan + Cemiplimab-Rwlc

Cemiplimab-Rwlc brand name: Libtayo.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Glucomannan and Cemiplimab-Rwlc 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Glucomannan and Cemiplimab-Rwlc

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 Cemiplimab-Rwlc and Glucomannan 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.

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.

Glucomannan safety at a glance

Glucomannan overall Use caution Generally well tolerated when taken with plenty of water, but it can cause choking or blockage if not swallowed properly.
Pregnancy Use caution Not enough reliable safety data; talk to your doctor before using during pregnancy.
Breastfeeding Use caution Little is known about its safety while breastfeeding, so caution is advised.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Cemiplimab-Rwlc and Glucomannan? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
Keep it in perspective

Glucomannan Does Interact With Other Medications

Glucomannan has 2,022 moderate known drug interactions in our database — Cemiplimab-Rwlc isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Glucomannan

Covers the 2,830 medications we’ve checked against Glucomannan. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Glucomannan and Cemiplimab-Rwlc May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • Liver problems Worth acting on Additional detail

    Glucomannan

    “Acute cholestatic hepatitis occurred in a 31-year-old male after taking glucomannan orally for 45 days. He was also taking other supplements, including garlic and chitosan, so it is unclear whether the hepatitis was due to glucomannan, other supplements, or the combination.”

    Glucomannan · Natural Medicines adverse-effect record, reported in hepatitis.

    1 source cited
    1. 57777. Villaverde, A. F., Benlloch, S., Berenguer, M., Miguel, Rayon J., Pina, R., and Berenguer, J. Acute hepatitis of cholestatic type possibly associated with the use of glucomannan (amorphophalus konjac). J Hepatol. 2004;41(6):1061-1062. PubMed

    Cemiplimab-Rwlc

    Listed in the ADVERSE REACTIONS section of the FDA label for Cemiplimab-Rwlc. Read the label on DailyMed ›

  • Constipation / Stomach pain / Diarrhea / Vomiting / Nausea Additional detail

    Glucomannan

    “Orally, glucomannan can cause gastrointestinal disturbances, including abdominal pain, bloating, constipation, diarrhea, flatulence, nausea, and vomiting, especially when taken in doses of more than 3 grams daily. Esophageal and gastrointestinal obstructions have been reported when dry glucomannan-containing products are taken with insufficient fluid.”

    Glucomannan · Natural Medicines adverse-effect record, reported in constipation.

    6 sources cited
    1. 57781. Yoshida, M., Vanstone, C. A., Parsons, W. D., Zawistowski, J., and Jones, P. J. Effect of plant sterols and glucomannan on lipids in individuals with and without type II diabetes. Eur.J Clin Nutr. 2006;60(4):529-537. PubMed
    2. 57784. Wood, R. J., Fernandez, M. L., Sharman, M. J., Silvestre, R., Greene, C. M., Zern, T. L., Shrestha, S., Judelson, D. A., Gomez, A. L., Kraemer, W. J., and Volek, J. S. Effects of a carbohydrate-restricted diet with and without supplemental soluble fiber
    3. 92004. Carabin IG, Lyon MR, Wood S, et al. Supplementation of the diet with the functional fiber PolyGlycoplex is well tolerated by healthy subjects in a clinical trial. Nutr J 2009;8:9. PubMed
    4. 92010. Lyon MR, Reichert RG. The effect of a novel viscous polysaccharide along with lifestyle changes on short-term weight loss and associated risk factors in overweight and obese adults: an observational retrospective clinical program analysis. Altern Med Rev
    5. 92011. Lyon M, Wood S, Pelletier X, et al. Effects of a 3-month supplementation with a novel soluble highly viscous polysaccharide on anthropometry and blood lipids in nondieting overweight or obese adults. J Hum Nutr Diet 2011;24(4):351-9. PubMed
    6. 97935. Han Y, Zhang L, Liu XQ, Zhao ZJ, Lv LX. Effect of glucomannan on functional constipation in children: a systematic review and meta-analysis of randomised controlled trials. Asia Pac J Clin Nutr 2017;26(3):471-7.

    Cemiplimab-Rwlc

    Listed in the ADVERSE REACTIONS section of the FDA label for Cemiplimab-Rwlc. Read the label on DailyMed ›

Reported for Glucomannan but not commonly for Cemiplimab-Rwlc: stomach upset, bloating or gas and wheezing.

Effects for Cemiplimab-Rwlc come from the ADVERSE REACTIONS section of its FDA label; effects for Glucomannan come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

One more smart check

Taking Glucomannan as Part of a Dietary Supplement Product? Check It for Interactions

We hold 467 real supplement products containing Glucomannan, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Glucomannan. Even though Glucomannan itself has no known interaction with Cemiplimab-Rwlc, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Glucomannan and Cemiplimab-Rwlc 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.

Supplement Glucomannan
Top 25%

#276 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Cemiplimab-Rwlc
Top half

#754 of 2,830 medications looked up here in the last 7 days

29 days ago today

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 Glucomannan reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Glucomannan and Cemiplimab-Rwlc 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.
Data structure & sourcing designed and verified by .
Supplement

About Glucomannan

What is Glucomannan?

Glucomannan
  • Weight loss and appetite control
  • Constipation
  • High cholesterol
  • Blood sugar support
  • Digestive health

Glucomannan is a soluble fiber from the konjac root that swells into a gel in your stomach, which may help with mild weight loss, constipation, and modestly lowering cholesterol. It is generally well tolerated when taken with plenty of water, but it must be taken carefully because it can swell and cause choking or blockage if not swallowed properly. Talk with your pharmacist or doctor before starting it, especially if you have a health condition or take medicines.

Amorphophallus konjac · Araceae · Root (tuber/corm) · Capsules, tablets, powder, drink mixes; also used as a food ingredient (konjac noodles, shirataki noodles)

An interaction check asks whether these two react with each other — it does not ask whether Glucomannan is a good idea for someone in your situation. Here is what our Glucomannan record says about it on its own.

Glucomannan: dosing

There is no single official standardized dose of glucomannan, and the right amount can vary by product and purpose. Because it is a concentrated fiber, the way you take it matters as much as the amount.The best advice is to follow the directions on the product label and to take each dose with a full glass of water (and drink fluids throughout the day).

From our Glucomannan monograph — the full record covers uses, side effects and every documented interaction.

Read the full Glucomannan monograph & all interactions
Medication

About Cemiplimab-rwlc Injection

What Is Cemiplimab-rwlc Injection Used For?

Brand name: Libtayo

Libtayo (cemiplimab-rwlc) is used to treat adults with several types of cancer. For skin cancers, it treats cutaneous squamous cell carcinoma (CSCC) that has spread or cannot be removed by surgery or radiation, and it is also used after surgery and radiation in people with CSCC at high risk of coming back. It also treats locally advanced or metastatic basal cell carcinoma (BCC) in adults who have already tried a hedgehog pathway inhibitor or cannot use one.

For lung cancer, Libtayo is used to treat adults with locally advanced or metastatic non-small cell lung cancer (NSCLC) — either alone (in tumors with high PD-L1 expression, confirmed by an FDA-approved test, with no certain genetic mutations) or combined with platinum-based chemotherapy (for tumors without specific EGFR, ALK, or ROS1 gene changes).

See full Cemiplimab-rwlc Injection drug information
Keep checking

Other Drugs & Glucomannan

Browse every other medication we’ve checked against Glucomannan — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
2,022Moderate
0Minor
807No known interaction
Moderate

2,022 interactions

Showing 60 of 2,022 moderate interactions — see all 2,022 on the Glucomannan page.

No interaction 807 drugs checked — show the list
Evidence & sources

Glucomannan References

The 15 references that drive our Glucomannan 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.

  1. Henry DA, Mitchell AS, Aylward J, et al. Glucomannan and risk of oesophageal obstruction. Br Med J 1986;292:591-2. PubMed
  2. Shima K, Tanaka A, Ikegami H, et al. Effect of dietary fiber, glucomannan, on absorption of sulfonylurea in man. Horm Metab Res 1983;15:1-3. PubMed
  3. Villaverde, A. F., Benlloch, S., Berenguer, M., Miguel, Rayon J., Pina, R., and Berenguer, J. Acute hepatitis of cholestatic type possibly associated with the use of glucomannan (amorphophalus konjac). J Hepatol. 2004;41(6):1061-1062. PubMed
  4. Yoshida, M., Vanstone, C. A., Parsons, W. D., Zawistowski, J., and Jones, P. J. Effect of plant sterols and glucomannan on lipids in individuals with and without type II diabetes. Eur.J Clin Nutr. 2006;60(4):529-537. PubMed
  5. Wood, R. J., Fernandez, M. L., Sharman, M. J., Silvestre, R., Greene, C. M., Zern, T. L., Shrestha, S., Judelson, D. A., Gomez, A. L., Kraemer, W. J., and Volek, J. S. Effects of a carbohydrate-restricted diet with and without supplemental soluble fiber
  6. Vanderbeek, P. B., Fasano, C., O'Malley, G., and Hornstein, J. Esophageal obstruction from a hygroscopic pharmacobezoar containing glucomannan. Clin Toxicol.(Phila) 2007;45(1):80-82. PubMed
  7. Bernstein, J. A., Crandall, M. S., and Floyd, R. Respiratory sensitization of a food manufacturing worker to konjac glucomannan. J Asthma 2007;44(8):675-680. PubMed
  8. Shichijo, K., Kobayashi, Y., Fueki, R., Shimoyama, K., and Masaya, M. [2 cases of konjac bronchial asthma found outside the "konnyaku" producing district]. Arerugi 1969;18(2):97-100.
  9. Carabin IG, Lyon MR, Wood S, et al. Supplementation of the diet with the functional fiber PolyGlycoplex is well tolerated by healthy subjects in a clinical trial. Nutr J 2009;8:9. PubMed
  10. Lyon MR, Reichert RG. The effect of a novel viscous polysaccharide along with lifestyle changes on short-term weight loss and associated risk factors in overweight and obese adults: an observational retrospective clinical program analysis. Altern Med Rev
  11. Lyon M, Wood S, Pelletier X, et al. Effects of a 3-month supplementation with a novel soluble highly viscous polysaccharide on anthropometry and blood lipids in nondieting overweight or obese adults. J Hum Nutr Diet 2011;24(4):351-9. PubMed
  12. Han Y, Zhang L, Liu XQ, Zhao ZJ, Lv LX. Effect of glucomannan on functional constipation in children: a systematic review and meta-analysis of randomised controlled trials. Asia Pac J Clin Nutr 2017;26(3):471-7.
  13. Health Canada Safety Alert. Health Canada Advises Canadians that natural health products containing glucomannan may cause serious choking if used with insufficient fluid. January 29, 2010. Alert # RA-110003825. https://healthycanadians.gc.ca/recall-alert-
  14. Mortensen A, Aguilar F, Crebelli, et al. EFSA Panel on Food Additives and Nutrient Sources added to Food. Re-evaluation of konjac gum (E 425 i) and konjac glucomannan (E425 ii) as food additives. EFSA Journal 2017;15(6):4864.
  15. Zhang Y, Aldamarany WAS, Song G, et al. Influence of konjac glucomannan and its derivatives on the oral pharmacokinetics of antimicrobial agent in antibiotics cocktails: Keep vigilant on dietary fiber supplement. Int J Biol Macromol 2023;251:126306. 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.

Pharmacist Counseling Corner

Taking Glucomannan and Cemiplimab-Rwlc Together: Common Questions

Is it safe to take Glucomannan with Cemiplimab-Rwlc?
We do not list a known interaction between Glucomannan and Cemiplimab-Rwlc. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Glucomannan and Cemiplimab-Rwlc have any of the same side effects?
Yes — our sources link each of them separately to 6 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Does Glucomannan interact with any other medications?
Yes. Glucomannan has 2,022 documented drug interactions in our database — Cemiplimab-Rwlc is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Cemiplimab-Rwlc and Glucomannan?

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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.