Interactions on record — worth a quick check against your medications. Based on 7 of 9 ingredients. Check your meds →
Dietary supplement

Carb Shield Ingredients & Drug Interactions

by Top Trainer

Carb Shield label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 30, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Carb Shield against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Carb Shield is a dietary supplement by Top Trainer with 9 active ingredients. Its ingredients are commonly taken for weight loss and appetite control, constipation, high cholesterol.Based on those ingredients, 2,155 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Glucomannan, Gymnema sylvestre, Cinnamon. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Carb Shield by Top Trainer

Ask about any prescription or over-the-counter medication and we check it for interactions with Carb Shield by Top Trainer — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Carb Shield by Top Trainer

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 12, 2026

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 9 active ingredients.
  • “Carb Shield Complex” is a proprietary blend — the label gives one combined amount (1,115.33 mg) without saying how much of each component you get.

Carb Shield has 9 ingredients, 6 of which are active. Glucomannan is a soluble fiber that may help with constipation and cholesterol; cinnamon (from the cassia plant) and white kidney bean extract are included for carbohydrate metabolism; chitosan is a fiber from shellfish that may support weight management; gymnema sylvestre is an herb traditionally used for blood sugar; and cassia nomame extract rounds out the blend.

The product also contains three digestive enzymes — amylase (breaks down carbs), protease (breaks down proteins), and lipase (breaks down fats). The inactive ingredients are rice flour, magnesium stearate, gelatin, titanium dioxide, and two yellow food dyes.

Does it work?

Moderate evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: carb and fat blocker for weight loss.
  • We looked for evidence on: Obesity, Dyslipidemia, Hypercholesterolemia, Hyperlipidemia, Metabolic syndrome, Appetite suppression — and 2 related terms.
  • The strongest evidence on file: Glucomannan is rated "Possibly Effective" for Hyperlipidemia (Natural Medicines).
  • Also on file: Chitosan is rated "Possibly Effective" for Obesity.
  • Also on file: Glucomannan is rated "Insufficient Reliable Evidence To Rate" for Obesity, Metabolic syndrome.

The evidence is mixed and mostly limited. Glucomannan is possibly effective for constipation and may help with cholesterol and blood sugar, though the data on cholesterol and diabetes is not strong.

Chitosan is possibly effective for weight and blood pressure support. Gymnema, cinnamon, and cassia nomame all show insufficient evidence in the data we hold — we don't have enough reliable research to say whether they work for their intended purposes.

The digestive enzymes (protease and lipase) likewise lack established evidence in our records; amylase data wasn't available to check.

The evidence, ingredient by ingredient Glucomannan Cassia Cinnamon Chitosan Cassia Nomame Gymnema Proteolytic Enzymes (proteases) Lipase

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 6 of the 7 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 7 of 7.
  • General safety write-ups exist for 7 of 7.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Glucomannan is generally well tolerated when you drink plenty of water with it, but it can cause bloating, gas, constipation, diarrhea, nausea, and abdominal pain — especially at doses over 3 grams daily. Rarely, it can cause choking or blockage in your throat or gut if not swallowed properly with liquid.

Cinnamon in food amounts is safe, but at supplement doses (especially high ones for long periods) there's concern about liver damage because of its coumarin content; one trial participant reported a rash, and rare cases of contact dermatitis have been reported. Chitosan is generally well tolerated short-term but can cause constipation, diarrhea, gas, nausea, and stomach discomfort.

Gymnema is well tolerated short-term, though one case of liver inflammation with jaundice was reported. Protease and lipase have little serious adverse effect data but may cause digestive upset or, very rarely, allergic reactions.

Side effects, ingredient by ingredient Glucomannan Cassia Cinnamon Chitosan Cassia Nomame Gymnema Proteolytic Enzymes (proteases) Lipase

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 4 of the 7 matched ingredients can interact with medications — Glucomannan, Chitosan, Gymnema, Cassia Cinnamon.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications.
  • For scale: 2,156 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking this product, double-check with your pharmacist if you take antidiabetes medications (risk of low blood sugar), warfarin or other blood thinners (increased bleeding risk), acyclovir or other antivirals, hepatotoxic drugs that stress the liver, or any medication that relies on CYP1A2, CYP2C9, or CYP3A4 liver enzymes for clearance. Glucomannan may also reduce absorption of oral medications, so separating doses by a few hours may help.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with some supporting evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Carb Shield may be worth considering if you're looking to support carb metabolism and digestion, but it's not for everyone. Do not take it if you're on a blood thinner like warfarin, take antiviral or diabetes medications, or use drugs that depend on liver enzymes for clearance — check with us first.

Talk to your pharmacist or doctor before starting, especially if you have a shellfish allergy or take any prescription medication.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 7 of 9 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated May 22, 2021.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Carb Shield, straight from the product label.

Brand Top Trainer
Net contents 120 Capsule(s)
Market status On market
Date entered into DSLD May 22, 2021
DSLD ID 249403
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Carb Shield by Top Trainer, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
60
IngredientAmount% DV
Glucomannan0 NP--
Cinnamon0 NP--
White Kidney Bean extract0 NP--
Chitosan0 NP--
Carb Shield Complex1115.33 mg--
Cassia nomame extract0 NP--
Gymnema sylvestre0 NP--
Amylase0 NP--
Protease0 NP--
Lipase0 NP--

Other ingredients: Rice Flour, Magnesium Stearate, Gelatin, Titanium Dioxide, FD&C Yellow #5, FD&C Yellow #6

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General Statements

Lose

Formulation

Stimulant free

Carb & fat blocker Supports weight loss & appetite control

FDA Statement of Identity

Dietary Supplement

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Carb Shield by Top Trainer label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Carb Shield label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Carb Shield by Top Trainer

These are the 9 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Capsule(s) Dosage formCapsule Servings per container60 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Carb Shield Complex

1115.33 mg per serving

Other (inactive) ingredients: Rice Flour, Magnesium Stearate, Gelatin, Titanium Dioxide, FD&C Yellow #5, FD&C Yellow #6. These complete the product’s ingredient list but are not active constituents.

Interaction report

Carb Shield by Top Trainer Drug Interactions

Want to check YOUR meds against Carb Shield?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
2,155Drugs
2,112 Moderate 43 Minor

Ingredients driving the most interactions

Glucomannan 2,022
Gymnema sylvestre 851
Cinnamon 442
Chitosan 3

Individual Drug Interactions

The ingredients in Carb Shield interact with 2,155 drugs. Click any drug to see the details.

4 of the 9 ingredients in Carb Shield interact with drugs. Each result below shows which ingredient is responsible. Glucomannan Gymnema sylvestre Cinnamon Chitosan

Each ingredient & the kinds of drugs it affects

For each ingredient in Carb Shield with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Glucomannan1 drug type · 2,022 drugs

Oral Drugs

Theoretically, glucomannan may decrease absorption of drugs taken orally.
Due to its viscosity and bulking effects, there is concern that glucomannan can decrease the absorption of oral drugs. A small clinical study in healthy volunteers shows that taking glyburide 2.5 mg plus glucomannan 3.9 grams with breakfast reduces plasma levels of glyburide when compared with breakfast and glyburide alone. In addition, animal research demonstrates this effect on amoxicillin, but shows increased absorption of metronidazole. This mouse model also demonstrates that metronidazole elimination is prolonged, but amoxicillin elimination is enhanced by 38%; glucomannan may also affect the distribution of some drugs. To avoid changes in absorption, take glucomannan 30-60 minutes after taking oral drugs.

Likelihood Probable Evidence B
Glucomannan full monograph & interactions

Gymnema sylvestre6 drug types · 851 drugs

Antidiabetes Drugs

Theoretically, taking gymnema with antidiabetes drugs might increase the risk of hypoglycemia.
Gymnema reduces blood glucose levels in some human and animal research. In human studies, it has been shown to enhance the blood glucose lowering effects of hypoglycemic drugs. However, other research in adults with prediabetes or metabolic syndrome suggests that gymnema does not reduce fasting levels of blood glucose. Until more is known, monitor blood glucose levels closely.

Likelihood Probable Evidence B
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, gymnema might increase levels of drugs metabolized by CYP1A2.
Animal and in vitro research shows that gymnema can inhibit the CYP1A2 enzyme. In one animal study, oral administration of gymnema for 7 days increased the plasma concentrations of phenacetin, a CYP1A2 substrate, by about 1.4-fold and reduced the clearance of phenacetin by about 29%.

Likelihood Possible Evidence D
Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, gymnema might increase or decrease levels of drugs metabolized by CYP2C9.
Animal research shows that gymnema can induce the CYP2C9 enzyme. In one animal study, gymnema caused a 2.4-fold increase in the clearance of tolbutamide, a CYP2C9 substrate, in rats. In vitro research also shows that gymnema can inhibit CYP2C9.

Likelihood Possible Evidence D
Phenacetin

Theoretically, taking gymnema with phenacetin might increase the levels of phenacetin.
Animal research shows that gymnema, administered orally for 7 days, decreases the clearance of phenacetin in a dose-dependent manner by about 21% to 29% and increases plasma levels about 1.3- to 1.4-fold when compared to control.

Likelihood Possible Evidence D
Tolbutamide (Orinase)

Theoretically, taking gymnema with tolbutamide might the decrease levels of tolbutamide.
Animal research shows that gymnema, administered orally for 7 days, increases the clearance of tolbutamide by 2.4-fold when compared to control.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, gymnema might increase levels of drugs metabolized by CYP3A4.
One in vitro study using rat liver microsomes shows that gymnema can modestly inhibit the CYP3A4 enzyme. However, other in vitro research using human liver microsomes shows that gymnema does not affect CYP3A4 activity. Animal research also shows that gymnema does not alter the function of CYP3A4. In one study in rats, oral administration of gymnema for 7 days did not alter the clearance of amlodipine, a CYP3A4 substrate.

Likelihood Unlikely Evidence D
Gymnema sylvestre full monograph & interactions

Cinnamon2 drug types · 442 drugs

Antidiabetes Drugs

Theoretically, cassia cinnamon may have additive effects with antidiabetes drugs.
Cassia cinnamon may lower blood glucose levels, and have additive effects in patients treated with antidiabetic agents. Dose adjustments to diabetes medications might be necessary.

Likelihood Possible Evidence B
Hepatotoxic Drugs

Theoretically, large doses of cassia cinnamon might cause additive effects when used with hepatotoxic drugs.
There is some concern that ingesting large amounts of cassia cinnamon for an extended duration might cause hepatotoxicity in some people. Cassia cinnamon contains coumarin, which can cause hepatotoxicity in animal models. In humans, very high doses of coumarin from 50-7000 mg/day can result in hepatotoxicity that resolves when coumarin use is discontinued. Lower amounts might also cause liver problems in sensitive people, such as those with liver disease or those taking potentially hepatotoxic agents.

Likelihood Possible Evidence D
Cinnamon full monograph & interactions

Chitosan2 drug types · 3 drugs

Acyclovir (Zovirax)

Chitosan can reduce the absorption of acyclovir, potentially increasing the risk for treatment failure.
Clinical research in humans shows that taking chitosan along with acyclovir 200 mg reduces acyclovir absorption. Concomitant administration of chitosan 400 mg or 1000 mg reduced the acyclovir area under the curve (AUC) and peak plasma concentration by about 30% and 40%, respectively, compared with control. Concomitant administration with chitosan 1000 mg also increased time to peak concentration from 1 hour to 2 hours. In vitro research suggests that the mechanism for reduced absorption is due to acyclovir entrapment in chitosan-mucus complexes, which reduces intestinal absorption.

Likelihood Possible Evidence B
Warfarin (Coumadin)

Theoretically, chitosan might increase the risk of bleeding when taken with warfarin.
In a case report, a patient taking warfarin had a significantly increased international normalized ratio (INR) after starting chitosan 1200 mg daily. The INR normalized after chitosan was discontinued and vitamin K was administered. The patient once again started taking chitosan and again had a significant increase in INR. The INR stabilized again once chitosan was discontinued. Researchers theorize that this interaction might occur because chitosan decreases absorption of fat-soluble vitamins, including vitamin K, which could increase the anticoagulant effect of warfarin.

Likelihood Possible Evidence D
Chitosan full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Carb Shield, from the product label.

Top Trainer

See all Top Trainer products
Name
Top Trainer
Pharmacist Counseling Corner

Carb Shield by Top Trainer: Common Questions

Does Carb Shield by Top Trainer interact with any medications?
Yes. Based on its ingredients, Carb Shield has a known interaction with 2,155 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Carb Shield contains 9 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Will this lower my blood sugar if I take diabetes medication?
Possibly. Cinnamon and gymnema both may lower blood glucose, and if you're already on a diabetes medication, taking them together could increase the risk of low blood sugar. Your dose may need adjusting. Talk with your doctor or pharmacist before starting.
Can I take this if I'm allergic to shellfish?
Probably not safely — chitosan, one of the active ingredients, is derived from shellfish. If you have a shellfish allergy, skip this product or check with your doctor first.
What side effects should I expect?
The most common ones are digestive: bloating, gas, constipation, diarrhea, nausea, and stomach discomfort. These happen especially when you take glucomannan without enough water. Drinking plenty of fluid when you take it helps.
Is it safe to take during pregnancy or while breastfeeding?
Not enough data exists for most of these ingredients. Glucomannan, cinnamon at supplement doses, chitosan, gymnema, cassia nomame, protease, and lipase all lack sufficient safety information in pregnancy or lactation. Talk with your doctor or pharmacist about whether this product is right for you.
Will this interfere with my blood thinner warfarin?
Yes — chitosan in this product has a documented interaction with warfarin and may increase your bleeding risk. Do not take this product if you're on warfarin without explicit approval from your doctor or pharmacist.
Does this product have fillers or unnecessary additives?
It contains inactive ingredients: rice flour, magnesium stearate, gelatin, titanium dioxide, and two yellow food dyes (FD&C Yellow #5 and #6). These are common in capsule supplements and serve as binders, flow agents, and capsule material.

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

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Carb Shield label
Go deeper

The Full Monographs Behind Carb Shield’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Glucomannan

Interacts with 2,022 drugs

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 gener...

Read the full Glucomannan monograph → Herb & supplement monograph

Cassia Cinnamon

Interacts with 442 drugs

Cassia cinnamon is the common, inexpensive cinnamon used in cooking, and it is also taken as a supplement, most often for blood sugar support. The evidence for its health benefits is mixed a...

Read the full Cassia Cinnamon monograph → Herb & supplement monograph

Chitosan

Interacts with 3 drugs

Chitosan is a fiber-like substance made from the shells of shrimp, crabs, and other shellfish, often marketed for weight loss and cholesterol. The evidence for these benefits is weak, and an...

Read the full Chitosan monograph → Herb & supplement monograph

Cassia Nomame

Cassia nomame is a legume plant traditionally used in parts of Asia and now marketed mainly in weight-loss supplements for its supposed ability to block fat absorption. Human evidence is ver...

Read the full Cassia Nomame monograph → Herb & supplement monograph

Gymnema

Interacts with 851 drugs

Gymnema is an Ayurvedic herb best known for possibly helping lower blood sugar and reducing the taste of sweetness on the tongue. Some early human studies are encouraging for blood sugar sup...

Read the full Gymnema monograph → Herb & supplement monograph

Proteolytic Enzymes (proteases)

Proteolytic enzymes are proteins that help break down other proteins, and common examples include bromelain (from pineapple), papain (from papaya), trypsin, chymotrypsin, and pancreatin. Peo...

Read the full Proteolytic Enzymes (proteases) monograph → Herb & supplement monograph

Lipase

Lipase is a digestive enzyme that helps your body break down dietary fats. It is well established as part of prescription pancreatic enzyme therapy for people who cannot make enough of their...

Read the full Lipase monograph →
Sources

Sources & How We Checked

Carb Shield's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 71 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Glucomannan 15 references
  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

See these in context on the Glucomannan monograph →

Cassia Cinnamon 20 references
  1. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  2. Khan A, Safdar M, Ali Khan M, et al. Cinnamon improves glucose and lipids of people with type 2 diabetes. Diabetes Care 2003;26:3215-8. PubMed
  3. De Benito V, Alzaga R. Occupational allergic contact dermatitis from cassia (Chinese cinnamon) as a flavouring agent in coffee. Contact Dermatitis 1999;40:165. PubMed
  4. Drake TE, Maibach HI. Allergic contact dermatitis and stomatitis caused by a cinnamic aldehyde-flavored toothpaste. Arch Dermatol 1976;112:202-3.
  5. Press release. Cinnamon capsules to reduce blood sugar are medicinal products! Efficacy has not been scientifically proven - some products contain high levels of coumarin. Federal Institute of Risk Assessment (BfM), Germany, November 11, 2006. Available a
  6. Felter SP, Vassallo JD, Carlton BD, Daston GP. A safety assessment of coumarin taking into account species-specificity of toxicokinetics. Food Chem Toxicol 2006;44:462-75. PubMed
  7. Crawford P. Effectiveness of cinnamon for lowering hemoglobin A1C in patients with type 2 diabetes: a randomized, controlled trial. J Am Board Fam Med 2009;22:507-12. PubMed
  8. Akilen, R., Tsiami, A., Devendra, D., and Robinson, N. Glycated haemoglobin and blood pressure-lowering effect of cinnamon in multi-ethnic Type 2 diabetic patients in the UK: a randomized, placebo-controlled, double-blind clinical trial. Diabet.Med. 2010; PubMed
  9. Lu T, Sheng H Wu J Cheng Y Zhu J Chen Y. Cinnamon extract improves fasting blood glucose and glycosylated hemoglobin level in Chinese patients with type 2 diabetes. Nutr Res. 2012;32(6):408-412. PubMed
  10. Choi, J., Lee, K. T., Ka, H., Jung, W. T., Jung, H. J., and Park, H. J. Constituents of the essential oil of the Cinnamomum cassia stem bark and the biological properties. Arch Pharm Res 2001;24(5):418-423.
  11. Altschuler JA, Casella SJ, MacKenzie TA, Curtis KM. The effect of cinnamon on A1C among adolescents with type 1 diabetes. Diabetes Care 2007;30(4):813-6. PubMed
  12. Stoecker BR, Zhan Z, Luo R, et al. Cinnamon extract lowers blood glucose in hyperglycemic subjects. FASEB J. 2010;22:722.1 (Abstract only). DOI
  13. Admani S, Hill H, Jacob SE. Cinnamon Sugar Scrub Dermatitis: "Natural" Is Not Always Best. Pediatr Dermatol. 2017;34(1):e42-e43. PubMed
  14. Isaac-Renton M, Li MK, Parsons LM. Cinnamon spice and everything not nice: many features of intraoral allergy to cinnamic aldehyde. Dermatitis. 2015;26(3):116-21. PubMed
  15. Vandersall A, Katta R. Eyelid dermatitis as a manifestation of systemic contact dermatitis to cinnamon. Dermatitis. 2015 Jul-Aug;26(4):189. PubMed
  16. Wickenberg J, Lindstedt S, Nilsson J, Hlebowicz J. Cassia cinnamon does not change the insulin sensitivity or the liver enzymes in subjects with impaired glucose tolerance. Nutr J 2014 Sep 24;13:96. PubMed
  17. Brancheau D, Patel B, Zughaib M. Do cinnamon supplements cause acute hepatitis? Am J Case Rep 2015;16:250-4. PubMed
  18. Shekarchizadeh-Esfahani P, Heydarpour F, Izadi F, Jalili C. The effect of cinnamon supplementation on liver enzymes in adults: A systematic review and meta-analysis of randomized controlled trials. Complement Ther Med 2021;58:102699. PubMed
  19. Bernaola J, Valverde-Monge M, Otal-Buesa M, Cullen D, Heras-Mendaza F. Cinnamon allergic contact cheilitis. Contact Dermatitis 2023;88(5):418-419. PubMed
  20. Patel K, Howard M, Tate B. Cheilitis caused by allergic contact dermatitis to cinnamon in chai tea: A case report. Contact Dermatitis 2023;88(3):239-240. PubMed

See these in context on the Cassia Cinnamon monograph →

Chitosan 17 references
  1. Jing SB, Li L, Ji D, et al. Effect of chitosan on renal function in patients with chronic renal failure. J Pharm Pharmacol 1997;49:721-3. PubMed
  2. Pittler MH, Abbot NC, Harkness EF, Ernst E. Randomized, double-blind trial of chitosan for body weight reduction. Eur J Clin Nutr 1999;53:379-81. PubMed
  3. Ho SC, Tai ES, Eng PH, et al. In the absence of dietary surveillance, chitosan does not reduce plasma lipids or obesity in hypercholesterolaemic obese Asian subjects. Singapore Med J 2001;42:6-10.
  4. Bokura H, Kobayashi S. Chitosan decreases total cholesterol in women: a randomized, double-blind, placebo-controlled trial. Eur J Clin Nutr 2003;57:721-5. PubMed
  5. Mhurchu CN, Poppitt SD, McGill AT, et al. The effect of the dietary supplement, Chitosan, on body weight: a randomised controlled trial in 250 overweight and obese adults. Int J Obes Relat Metab Disord 2004;28:1149-56. PubMed
  6. Huang SS, Sung SH, Chiang CE. Chitosan potentiation of warfarin effect. Ann Pharmacother 2007;41:1912-4. PubMed
  7. Tsai, G. J. and Su, W. H. Antibacterial activity of shrimp chitosan against Escherichia coli. J Food Prot. 1999;62(3):239-243. PubMed
  8. Wuolijoki, E., Hirvela, T., and Ylitalo, P. Decrease in serum LDL cholesterol with microcrystalline chitosan. Methods Find.Exp Clin Pharmacol. 1999;21(5):357-361. PubMed
  9. Nelson, J. L., Alexander, J. W., Gianotti, L., Chalk, C. L., and Pyles, T. Influence of dietary fiber on microbial growth in vitro and bacterial translocation after burn injury in mice. Nutrition 1994;10(1):32-36.
  10. Schiller RN, Barrager E, Schauss EA, and et al. A randomized, double-blind, placebo-controlled study examining the effects of a rapidly soluble chitosan dietary supplement on weight loss and body composition in overweight and mildly obese individuals. J
  11. Koide, S. S. Chitin-chitosan: properties, benefits and risks. Nutrition Research 1998;8(6):1091-1101. DOI
  12. Maezaki Y, Tsuji K, Nakawa, and et al. Hypocholesterolaemic effect of chitosan in adult males. Biosc Biochem Biotech 1993;57:1439-1444.
  13. Kubbinga M, Nguyen MA, Staubach P, et al. The influence of chitosan on the oral bioavailability of acyclovir-a comparative bioavailability study in humans. Pharm Res 2015;32(7):2241-9. PubMed
  14. Jull AB, Ni Mhurchu C, Bennett DA, et al. Chitosan for overweight or obesity. Cochrane Database Syst Rev 2008;(3):CD003892. PubMed
  15. Schmidl D, Werkmeister R, Kaya S, et al. A Controlled, Randomized Double-Blind Study to Evaluate the Safety and Efficacy of Chitosan-N-Acetylcysteine for the Treatment of Dry Eye Syndrome. J Ocul Pharmacol Ther. 2017;33(5):375-382.
  16. Moraru C, Mincea MM, Frandes M, Timar B, Ostafe V. A meta-analysis on randomised controlled clinical trials evaluating the effect of the dietary supplement chitosan on weight loss, lipid parameters and blood pressure. Medicina (Kaunas). 2018;54(6):109. PubMed
  17. García MA, Hensler G, Al-Gousous J, Pielenhofer J, Wagner M, Lennernäs H, Langguth P. Novel food drug interaction mechanism involving acyclovir, chitosan and endogenous mucus. Drug Metab Pharmacokinet. 2023;49:100491. PubMed

See these in context on the Chitosan monograph →

Cassia Nomame 3 references
  1. Dietary Supplements for Weight Loss — NIH Office of Dietary Supplements Source
  2. Herbs at a Glance — NIH NCCIH Source
  3. Dietary Supplements — MedlinePlus Source

See these in context on the Cassia Nomame monograph →

Gymnema 12 references
  1. Shanmugasundaram ER, Rajeswari G, Baskaran K, et al. Use of Gymnema sylvestre leaf extract in the control of blood glucose in insulin-dependent diabetes mellitus. J Ethnopharmacol 1990;30:281-94. PubMed
  2. Baskaran K, Kizar Ahamath B, Radha Shanmugasundaram K, Shanmugasundaram ER. Antidiabetic effect of leaf extract from Gymnema sylvestre in non-insulin-dependent diabetes mellitus patients. J Ethnopharmacol 1990;30:295-300.
  3. Kamble B, Gupta A, Moothedath I, Khatal L, Janrao S, Jadhav A, et al. Effects of Gymnema sylvestre extract on the pharmacokinetics and pharmacodynamics of glimepiride in streptozotocin induced diabetic rats. Chem Biol Interact. 2016;245:30-8. PubMed
  4. Tiwari P, Mishra BN, Sangwan NS. Phytochemical and pharmacological properties of Gymnema sylvestre: an important medicinal plant. Biomed Res Int. 2014; 2014:830285.
  5. Fabio GD, Romanucci V, De Marco A, Zarrelli A. Triterpenoids from Gymnema sylvestre and their pharmacological activities. Molecules. 2014;19(8):10956-81. PubMed
  6. Shiyovich A, Sztarkier I, Nesher L. Toxic hepatitis induced by Gymnema sylvestre, a natural remedy for type 2 diabetes mellitus. Am J Med Sci. 2010;340(6):514-7. PubMed
  7. Zuniga LY, Gonzalez-Ortiz M, Martinez-Abundis E. Effect of gymnema sylvestre administration on metabolic syndrome, insulin sensitivity, and insulin secretion. J Med Food. 2017 Aug;20(8):750-54.
  8. Rammohan B, Samit K, Chinmoy D, et al. Human cytochrome P450 enzyme modulation by gymnema sylvestre: a predictive safety evaluation by LC-MS/MS. Pharmacogn Mag. 2016 Jul;12(Suppl 4):S389-S394.
  9. Vaghela M, Sahu N, Kharkar P, Pandita N. In vivo pharmacokinetic interaction by ethanolic extract of gymnema sylvestre with CYP2C9 (tolbutamide), CYP3A4 (amlodipine) and CYP1A2 (phenacetin) in rats. Chem Biol Interact. 2017 Dec 25;278:141-151. PubMed
  10. Vaghela M, Iyer K, Pandita N. In vitro inhibitory effect of gymnema sylvestre extracts and total gymnemic acids fraction on select cytochrome P450 activities in rat liver microsomes. Eur J Drug Metab Pharmacokinet. 2017 Oct 10. PubMed
  11. Gaytán Martínez LA, Sánchez-Ruiz LA, Zuñiga LY, González-Ortiz M, Martínez-Abundis E. Effect of Gymnema sylvestre administration on glycemic control, insulin secretion, and insulin sensitivity in patients with impaired glucose tolerance. J Med Food. 2021;
  12. Philips CA, Theruvath AH, Ravindran R. Toxic hepatitis-associated aplastic anaemia after dual homeopathic remedies and Gymnema sylvestre use. BMJ Case Rep 2022;15(3):e247867. PubMed

See these in context on the Gymnema monograph →

Proteolytic Enzymes (proteases) 3 references
  1. Weeks JA, Harper RA, Simon RA, Burdick JD. Assessment of sensitization risk of a laundry pre-spotter containing protease. Cutan Ocul Toxicol. 2011;30(4):272-9. PubMed
  2. Marquès LI, Lara S, Abós T, Bartolomé B. Occupational rhinitis due to pepsin. J Investig Allergol Clin Immunol. 2006;16(2):136-7. DOI
  3. Cartier A, Malo JL, Pineau L, Dolovich J. Occupational asthma due to pepsin. J Allergy Clin Immunol. 1984;73(5 Pt 1):574-7. PubMed

See these in context on the Proteolytic Enzymes (proteases) monograph →

Lipase 1 reference
  1. Casper C, Hascoet JM, Ertl T, et al. Recombinant bile salt-stimulated lipase in preterm infant feeding: A randomized phase 3 study. PLoS One. 2016;11(5):e0156071. PubMed

See these in context on the Lipase monograph →

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DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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