Interactions on record — worth a quick check against your medications. Based on 10 of 13 ingredients. Check your meds →
Dietary supplement

GDA+ Ingredients & Drug Interactions

by Axe & Sledge Supplements

GDA+ label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 23, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking GDA+ 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

GDA+ is a dietary supplement by Axe & Sledge Supplements with 13 active ingredients. Its ingredients are commonly taken for digestive support, bloating and gas, fat digestion.Based on those ingredients, 2,192 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Glucomannan, Black Pepper extract, GS4 Plus. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against GDA+ by Axe & Sledge Supplements

Ask about any prescription or over-the-counter medication and we check it for interactions with GDA+ by Axe & Sledge Supplements — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of GDA+ by Axe & Sledge Supplements

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 30, 2026

What’s inside

Partial disclosure
Ingredient Transparency · database check
Partial

Most active ingredients list an amount, but at least one is hidden in a blend or missing.

Why this rating?
  • The label discloses an exact amount for 8 of its 13 active ingredients.
  • “Enzyme Blend” is a proprietary blend — the label gives one combined amount (50 mg) without saying how much of each component you get.
  • “Fat Blocking Complex” is a proprietary blend — the label gives one combined amount (625 mg) without saying how much of each component you get.
  • “Carbohydrate Blocking” is listed as a grouped ingredient — the label gives one combined amount (400 mg) without saying how much of each component you get.

GDA+ contains 13 active ingredients spread across three digestive enzyme complexes. The first group includes lipase, lactase, and proteases—enzymes that break down fat, milk sugar, and protein respectively.

The second group, labeled Fat Blocking Complex, features black pepper extract and glucomannan alongside other components we cannot fully assess. The third group, Carbohydrate Blocking, includes prickly pear, chitosan, cinnamon bark extract, garcinia cambogia extract, and GS4 Plus (gymnema).

Several inactive ingredients round out the formula—cellulose, magnesium stearate, silicon dioxide, and gelatin form the capsule structure.

Does it work?

Strong 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
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: carbohydrate and fat digestion support.
  • We looked for evidence on: Constipation, Diarrhea, Dyspepsia, Flatulence, Lactose intolerance, Nutrient absorption — and 1 related terms.
  • The strongest evidence on file: Lactase is rated "Effective" for Lactose intolerance (Natural Medicines).
  • Also on file: Glucomannan is rated "Possibly Effective" for Constipation.
  • Also on file: Lipase is rated "Insufficient Reliable Evidence To Rate" for Dyspepsia.

Lactase is effective for lactose intolerance. Glucomannan is possibly effective for constipation, diabetes, and high cholesterol.

Prickly pear and cinnamon bark extract are each possibly effective for diabetes. Chitosan is possibly effective for obesity and high blood pressure.

Garcinia and gymnema show insufficient reliable evidence in our data for their marketed uses—obesity, athletic performance, and prediabetes are all rated inconclusive. For lipase, proteases, black pepper, and the enzyme blends, the evidence in our data doesn't establish whether they work as claimed for digestive support or other purposes.

The evidence, ingredient by ingredient Lipase Lactase Proteolytic Enzymes (proteases) Black Pepper Prickly Pear Cactus Chitosan Cassia Cinnamon Glucomannan

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 10 of the 10 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 10 of 10.
  • General safety write-ups exist for 10 of 10.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Lipase is generally well tolerated but people with serious digestive conditions should use it only under medical guidance. Lactase is generally well tolerated; safety in pregnancy is likely okay.

Proteases may cause digestive upset or allergic reactions and should be avoided in pregnancy. Black pepper is well tolerated in food amounts; burning aftertaste and digestive discomfort are the most common complaints.

Glucomannan must be taken with plenty of water to avoid choking or blockage—gastrointestinal disturbances like bloating and constipation are common. Prickly pear is generally well tolerated as food, though supplement amounts are not well studied and should be avoided in pregnancy and breastfeeding.

Chitosan is generally well tolerated short-term; constipation and nausea are common. Cinnamon bark extract is safe in food amounts; avoid high-dose supplements in pregnancy due to limited safety data.

Garcinia has rare reports of liver injury, mania, and heart inflammation. Gymnema can lower blood sugar and is best avoided in pregnancy and breastfeeding.

Side effects, ingredient by ingredient Lipase Lactase Proteolytic Enzymes (proteases) Black Pepper Prickly Pear Cactus Chitosan Cassia Cinnamon Glucomannan

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?
  • 7 of the 10 matched ingredients can interact with medications — Glucomannan, Chitosan, Black Pepper, Garcinia, Gymnema, among others.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; diabetes medications; lithium.
  • For scale: 2,193 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.

Check with your doctor or pharmacist before using this product if you take diabetes medications (risk of low blood sugar from prickly pear and gymnema), blood thinners like warfarin (chitosan may increase bleeding risk; garcinia may also interfere), heart-rhythm or blood-pressure medications like propranolol (black pepper may raise levels), seizure drugs like phenytoin (black pepper may raise levels), cholesterol drugs like atorvastatin (black pepper may raise levels), asthma medications like theophylline (black pepper may raise levels), antiviral drugs like acyclovir or nevirapine (chitosan and black pepper respectively may reduce or raise absorption), immunosuppressants like cyclosporine (black pepper may raise levels), sedatives like pentobarbital (black pepper may increase drowsiness), antidepressants (garcinia carries a rare serotonin syndrome risk), or any drug broken down by your liver's CYP1A2, CYP2C9, or CYP3A4 enzymes (gymnema may alter levels).

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glancePartially disclosed formula with clinical evidence supporting its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

GDA+ is a 13-ingredient digestive-support product that combines enzymes and plant extracts. If you take diabetes medications, blood thinners, heart medications, anticonvulsants, or antidepressants, review this product with your doctor or pharmacist first—several ingredients interact with these drug types.

The product is not well studied overall, and evidence for weight loss or carb blocking is insufficient. Talk it over with your own healthcare provider before starting, especially if you have a sensitive stomach, take medications regularly, or are pregnant or breastfeeding.

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

Assessment coverage: 10 of 13 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Oct 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 GDA+, straight from the product label.

Brand Axe & Sledge Supplements
Barcode (UPC) 753577017215
Net contents 90 Capsule(s)
Market status On market
Date entered into DSLD Oct 22, 2021
DSLD ID 254768
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Women (not pregnant or lactating), Gluten Free
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 GDA+ by Axe & Sledge Supplements, 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:
4 Capsule(s)
Servings per container
45
UPC/BARCODE
753577017215
IngredientAmount% DV
Lipase0 NP--
Lactase0 NP--
Proteases0 NP--
Enzyme Blend50 mg--
Amylases0 NP--
Black Pepper extract5 mg--
White Kidney Bean extract250 mg--
Glucomannan75 mg--
Prickly Pear75 mg--
LipoSan Ultra Chitosan500 mg--
DigeSEB0 NP--
Fat Blocking Complex625 mg--
Cinnamon bark extract50 mg--
Carbohydrate Blocking400 mg--
Garcinia cambogia extract75 mg--
GS4 Plus400 mg--

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

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.
Suggested/Recommended/Usage/Directions

About GDA+ & suggested use Basically - the MORE fat and carbohydrates you consume during the a meal, the More GDA+ capsules you will need to take. Below is a sample chart demonstrating how much GDA+ you'll need to take based on the number of calories (grams) of food you intend on eating. Carbohydrates per meal 45-64 grams (180-250 calories) 65-84 grams (250-340 calories) 85+ grams (350+ calories) Fats per meal 8-15 grams (70-135 calories) 16-24 grams (145-216 calories) 25+ grams (225 calories) 20-30 minutes before meal 2 capsules 3 capsules 4 capsules

General Statements

When not to take GDA+: there is no need to take GDA when consuming a meal with protein and vegetables (low or no carb/fat meal). There is nothing in your body for it to block hence, a waste of money.

For the hardest workers in the gym

Precautions

Warning: Consult with a physician prior to use if you have a medical condition.

Don't use if pregnant or lactating.

Keep out of reach of children.

Storage

Keep container tightly closed in a cool, dry and dark place.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Brand IP Statement(s)

BioPerine is a trademark of Sabinsa.

Formulation

Inspected Facility Good Manufacturing Facility cGMP

Gluten free

Glucose Disposal Agent

Seals/Symbols

Made in the USA with pride

Formula

LipoSan Ultra Gymnema sylvestre + Superior Quality BioPerine

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

GDA+ by Axe & Sledge Supplements label

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

GDA+ 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 GDA+ by Axe & Sledge Supplements

These are the 13 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Capsule(s) Dosage formCapsule Servings per container45 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.

Enzyme Blend

50 mg per serving

Black Pepper extract

Interacts with
1,019 drugs
5 mg per serving

Black pepper is a common kitchen spice that is generally safe in the amounts used in food. Its extract, piperine, is mostly added to supplements to he...

Black Pepper extract monograph & interactions

Fat Blocking Complex

625 mg per serving

Carbohydrate Blocking

400 mg per serving

GS4 Plus

Interacts with
851 drugs
400 mg per serving Form: Gymnemic Acids

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 stu...

GS4 Plus monograph & interactions

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

Interaction report

GDA+ by Axe & Sledge Supplements Drug Interactions

Want to check YOUR meds against GDA+?

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
2,192Drugs
2,192 Moderate

Ingredients driving the most interactions

Glucomannan 2,022
Black Pepper extract 1,019
GS4 Plus 851
Garcinia cambogia extract 704
Cinnamon bark extract 442

Individual Drug Interactions

The ingredients in GDA+ interact with 2,192 drugs. Click any drug to see the details.

7 of the 13 ingredients in GDA+ interact with drugs. Each result below shows which ingredient is responsible. Glucomannan Black Pepper extract GS4 Plus Garcinia cambogia extract Cinnamon bark extract Prickly Pear LipoSan Ultra Chitosan

Each ingredient & the kinds of drugs it affects

For each ingredient in GDA+ 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

Black Pepper extract17 drug types · 1,019 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, black pepper might increase the risk of bleeding when taken with antiplatelet or anticoagulant drugs.
In vitro research shows that piperine, a constituent of black pepper, seems to inhibit platelet aggregation. This has not been reported in humans.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, black pepper might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Animal research shows that piperine, a constituent of black pepper, can reduce blood glucose levels. Monitor blood glucose levels closely. Dose adjustments might be necessary.

Likelihood Possible Evidence D
Atorvastatin (Lipitor)

Theoretically, black pepper might increase blood levels of atorvastatin.
Animal research shows that taking piperine, a constituent of black pepper, 35 mg/kg can increase the maximum serum concentration of atorvastatin three-fold. This has not been reported in humans.

Likelihood Possible Evidence D
Cyclosporine (Neoral, Sandimmune)

Theoretically, black pepper might increase the effects and side effects of cyclosporine.
In vitro research shows that piperine, a constituent of black pepper, increases the bioavailability of cyclosporine. This has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, black pepper might increase levels of drugs metabolized by CYP2D6.
In vitro research suggests that some constituents of black pepper inhibit CYP2D6. This has not been reported in humans.

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

Theoretically, black pepper might increase levels of drugs metabolized by CYP3A4.
In vitro research and pharmacokinetic simulation data suggest that piperine, a constituent of black pepper, as well as the pepper fruit seem to inhibit CYP3A4. This has not been reported in humans.

Likelihood Possible Evidence D
Lithium

Theoretically, black pepper might increase blood levels of lithium due to its diuretic effects. The dose of lithium might need to be reduced.
Black pepper is thought to have diuretic properties.

Likelihood Probable Evidence D
Nevirapine (Viramune)

Black pepper might increase blood levels of nevirapine.
Clinical research shows that piperine, a constituent of black pepper, increases the plasma concentration of nevirapine. However, no adverse effects were observed in this study.

Likelihood Probable Evidence D
P-Glycoprotein Substrates

Theoretically, black pepper might increase levels of P-glycoprotein substrates.
In vitro research shows that piperine, a constituent of black pepper, seems to inhibit P-glycoprotein.

Likelihood Possible Evidence D
Pentobarbital (Nembutal)

Theoretically, black pepper might increase the sedative effects of pentobarbital.
Animal research shows that piperine, a constituent of black pepper, increases pentobarbital-induced sleeping time.

Likelihood Possible Evidence D
Phenytoin (Dilantin)

Black pepper might increase blood levels of phenytoin.
Clinical research shows that piperine, a constituent of black pepper, seems to increase absorption, slow elimination, and increase levels of phenytoin. Taking a single dose of black pepper 1 gram along with phenytoin seems to double the serum concentration of phenytoin. Consuming a soup with black pepper providing piperine 44 mg/200 mL of soup along with phenytoin also seems to increase phenytoin levels when compared with consuming the same soup without black pepper.

Likelihood Possible Evidence B
Propranolol (Inderal)

Black pepper might increase blood levels of propranolol.
Clinical research shows that piperine, a constituent of black pepper, seems to increase absorption and slow elimination of propranolol.

Likelihood Possible Evidence B
Rifampin (Rifadin)

Black pepper might increase blood levels of rifampin.
Clinical research shows that piperine, a constituent of black pepper, seems to increase absorption and serum levels of rifampin.

Likelihood Possible Evidence B
Theophylline

Black pepper might increase blood levels of theophylline.
Clinical research shows that piperine, a constituent of black pepper, seems to increase absorption and slow elimination of theophylline.

Likelihood Possible Evidence D
Amoxicillin (Amoxil, Trimox)

Theoretically, black pepper might increase the effects and side effects of amoxicillin.
Animal research shows that taking piperine, a constituent of black pepper, with amoxicillin increases plasma levels of amoxicillin. This has not been reported in humans.

Likelihood Possible Evidence D
Carbamazepine (Tegretol)

Theoretically, black pepper might increase blood levels of carbamazepine, potentially increasing the effects and side effects of carbamazepine.
One clinical study in patients taking carbamazepine 300 mg or 500 mg twice daily shows that taking a single 20 mg dose of purified piperine, a constituent of black pepper, increases carbamazepine levels. Piperine may increase carbamazepine absorption by increasing blood flow to the GI tract, increasing the surface area of the small intestine, or inhibiting cytochrome P450 3A4 (CYP3A4) in the gut wall. Absorption was significantly increased by 7-10 mcg/mL/hour. The time to eliminate carbamazepine was also increased by 4-8 hours. Although carbamazepine levels were increased, this did not appear to increase side effects. In vitro research also shows that piperine can increase carbamazepine levels by 11% in a time-dependent manner.

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

Theoretically, black pepper might decrease levels and clinical effects of drugs metabolized by CYP1A2.
In vitro research suggests that black pepper induces CYP1A2. This has not been reported in humans.

Likelihood Possible Evidence D
Black Pepper extract full monograph & interactions

GS4 Plus6 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
GS4 Plus full monograph & interactions

Garcinia cambogia extract4 drug types · 704 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, hydroxycitric acid (HCA), the main active ingredient in garcinia, might increase the risk of bleeding when used with antiplatelet or anticoagulant drugs.
HCA inhibits platelet aggregation in vitro. The inhibitory effect seems to be greater in platelets extracted from diabetic subjects than non-diabetic subjects.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, hydroxycitric acid (HCA), the main active ingredient in garcinia, might have additive effects with antidiabetes drugs and increase the risk of hypoglycemia.
HCA reduces fasting and postprandial blood glucose levels in animal models, theoretically by delaying glucose absorption. This effect has not been reported in humans.

Likelihood Possible Evidence D
Hepatotoxic Drugs

Theoretically, concomitant use with other potentially hepatotoxic drugs might increase the risk of developing liver damage.
There have been reports of acute hepatitis with elevated liver enzymes associated with garcinia, when taken alone or in combination with other ingredients. Case reports collected from the Drug Induced Liver Injury Network suggest this risk may be greater in people who carry the HLA B*35:01 allele.

Likelihood Possible Evidence D
Serotonergic Drugs

Theoretically, combining garcinia with other serotonergic drugs might increase the risk of serotonergic side effects, including serotonin syndrome.
In one report, a patient experienced serotonin syndrome after taking garcinia extract (60% hydroxycitric acid) 1000 mg daily in combination with escitalopram 20 mg, which had been taken for a year. The patient was switched to sertraline 50 mg daily and again experienced serotonin syndrome.

Likelihood Possible Evidence D
Garcinia cambogia extract full monograph & interactions

Cinnamon bark extract2 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 bark extract full monograph & interactions

Prickly Pear1 drug type · 86 drugs

Antidiabetes Drugs

Combining prickly pear cactus with antidiabetes drugs might increase the risk of hypoglycemia.
Case reports show that combining prickly pear cactus with antidiabetes drugs such as chlorpropamide, glyburide, glipizide, and metformin can increase the risk of hypoglycemia in patients with type 2 diabetes. Advise patients to monitor glucose levels closely. Dose adjustments may be necessary.

Likelihood Probable Evidence D
Prickly Pear full monograph & interactions

LipoSan Ultra 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
LipoSan Ultra Chitosan full monograph & interactions
The maker

Brand information

Manufacturer and brand details for GDA+, from the product label.

Axe & Sledge Supplements

See all Axe & Sledge Supplements products
Name
Axe & Sledge Supplements
Street Address
1909 New Texas Road
City
Pittsburgh
State
PA
ZipCode
15239
Phone Number
(888) 944-6612
Web Address
www.axeandsledge.com
Pharmacist Counseling Corner

GDA+ by Axe & Sledge Supplements: Common Questions

Does GDA+ by Axe & Sledge Supplements interact with any medications?
Yes. Based on its ingredients, GDA+ has a known interaction with 2,192 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
GDA+ contains 13 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.
Is lactase safe if I'm pregnant?
Yes—lactase is rated likely safe in pregnancy according to our data. If you're pregnant and lactose intolerant, it's a reasonable option, but as always, confirm with your own doctor or pharmacist first.
Can I take this if I have a shellfish allergy?
Chitosan is derived from shellfish, so if you have a shellfish allergy, you should avoid this product. Check with your doctor or pharmacist before using.
What does glucomannan do?
Glucomannan is a water-soluble fiber that absorbs liquid and bulks up in your digestive tract. It's possibly effective for constipation, high cholesterol, and blood sugar control. Always take it with plenty of water to prevent choking or blockage.
Is black pepper extract safe during pregnancy?
Our data shows black pepper is rated likely unsafe in pregnancy, so it should be avoided during pregnancy. Talk with your doctor or pharmacist for personalized advice.
Will this product help me lose weight?
The ingredients most marketed for weight loss—garcinia and gymnema—do not have sufficient reliable evidence in our data to support that claim. Chitosan is possibly effective for obesity, but overall, this product's weight-loss benefit is not well established.
Can I take this with my stomach medication?
It depends on which medication. Glucomannan may slow absorption of oral drugs, so space it several hours apart from other medications if possible. Check the specific medication with your doctor or pharmacist—they can tell you whether timing matters for you.

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.

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The Full Monographs Behind GDA+’s Ingredients

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

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 → Herb & supplement monograph

Lactase

Lactase is a digestive enzyme supplement that helps people who lack enough natural lactase break down lactose, the sugar in milk and dairy. It can reduce gas, bloating, cramping, and diarrhe...

Read the full Lactase 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

Black Pepper

Interacts with 1,019 drugs

Black pepper is a common kitchen spice that is generally safe in the amounts used in food. Its extract, piperine, is mostly added to supplements to help the body absorb other ingredients (li...

Read the full Black Pepper monograph → Herb & supplement monograph

Prickly Pear Cactus

Interacts with 86 drugs

Prickly pear cactus is a desert plant whose pads and fruit are eaten as food and taken as a supplement, mainly for blood sugar, cholesterol, and hangover symptoms. Some small studies suggest...

Read the full Prickly Pear Cactus 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 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

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

Garcinia

Interacts with 704 drugs

Garcinia is a tropical fruit whose rind contains hydroxycitric acid (HCA), widely marketed for weight loss and appetite control. The scientific evidence is weak and mixed, with most studies...

Read the full Garcinia 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 →
Sources

Sources & How We Checked

GDA+'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 151 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.

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 →

Lactase 1 reference
  1. Laukkanen A, Ruoppi P, Remes S, Koistinen T, Mäkinen-Kiljunen S. Lactase-induced occupational protein contact dermatitis and allergic rhinoconjunctivitis. Contact Dermatitis. 2007;57(2):89-93. PubMed

See these in context on the Lactase 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 →

Black Pepper 29 references
  1. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  2. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  3. Bano G, Amla V, Raina RK, et al. The effect of piperine on pharmacokinetics of phenytoin in healthy volunteers. Planta Med 1987;53:568-9. PubMed
  4. Bano G, et al. Effect of piperine on bioavailability and pharmacokinetics of propranolol and theophylline in healthy volunteers. Eur J Clin Pharmacol 1991;41;615-7. PubMed
  5. Cohle SD, Trestrail JD III, Graham MA, et al. Fatal pepper aspiration. Am J Dis Child 1988;142:633-6. PubMed
  6. Bhardwaj RK, Glaeser H, Becquemont L, et al. Piperine, a major constituent of black pepper, inhibits human P-glycoprotein and CYP3A4. J Pharmacol Exp Ther 2002;302:645-50. PubMed
  7. Velpandian T, Jasuja R, Bhardwaj RK, et al. Piperine in food: interference in the pharmacokinetics of phenytoin. Eur J Drug Metab Pharmacokinet 2001;26:241-7. PubMed
  8. Pattanaik S, Hota D, Prabhakar S, et al. Pharmacokinetic interaction of a single dose of piperine with steady-state carbamazepine in epilepsy patients. Phytother Res 2009;23:1281-6.
  9. Munakata, M., Kobayashi, K., Niisato-Nezu, J., Tanaka, S., Kakisaka, Y., Ebihara, T., Ebihara, S., Haginoya, K., Tsuchiya, S., and Onuma, A. Olfactory stimulation using black pepper oil facilitates oral feeding in pediatric patients receiving long-term en
  10. Myers, B. M., Smith, J. L., and Graham, D. Y. Effect of red pepper and black pepper on the stomach. Am J Gastroenterol 1987;82(3):211-214.
  11. Raghavendra, R. H. and Naidu, K. A. Spice active principles as the inhibitors of human platelet aggregation and thromboxane biosynthesis. Prostaglandins Leukot.Essent.Fatty Acids 2009;81(1):73-78. PubMed
  12. Subehan, Usia, T., Kadota, S., and Tezuka, Y. Mechanism-based inhibition of human liver microsomal cytochrome P450 2D6 (CYP2D6) by alkamides of Piper nigrum. Planta Med 2006;72(6):527-532.
  13. Kasibhatta, R. and Naidu, M. U. Influence of piperine on the pharmacokinetics of nevirapine under fasting conditions: a randomised, crossover, placebo-controlled study. Drugs R.D. 2007;8(6):383-391. PubMed
  14. Usia, T., Iwata, H., Hiratsuka, A., Watabe, T., Kadota, S., and Tezuka, Y. CYP3A4 and CYP2D6 inhibitory activities of Indonesian medicinal plants. Phytomedicine. 2006;13(1-2):67-73. PubMed
  15. Mujumdar, A. M., Dhuley, J. N., Deshmukh, V. K., Raman, P. H., Thorat, S. L., and Naik, S. R. Effect of piperine on pentobarbitone induced hypnosis in rats. Indian J Exp.Biol. 1990;28(5):486-487.
  16. Panda, S. and Kar, A. Piperine lowers the serum concentrations of thyroid hormones, glucose and hepatic 5'D activity in adult male mice. Horm.Metab Res. 2003;35(9):523-526. PubMed
  17. Lawless, H. and Stevens, D. A. Effects of oral chemical irritation on taste. Physiol Behav. 1984;32(6):995-998. PubMed
  18. Hiwale, A. R., Dhuley, J. N., and Naik, S. R. Effect of co-administration of piperine on pharmacokinetics of beta-lactam antibiotics in rats. Indian J Exp.Biol. 2002;40(3):277-281.
  19. Han, Y., Chin Tan, T. M., and Lim, L. Y. In vitro and in vivo evaluation of the effects of piperine on P-gp function and expression. Toxicol.Appl.Pharmacol. 8-1-2008;230(3):283-289. PubMed
  20. Sharma, P., Varma, M. V., Chawla, H. P., and Panchagnula, R. In situ and in vivo efficacy of peroral absorption enhancers in rats and correlation to in vitro mechanistic studies. Farmaco 2005;60(11-12):874-883. PubMed
  21. Aher, S., Biradar, S., Gopu, C. L., and Paradkar, A. Novel pepper extract for enhanced P-glycoprotein inhibition. J Pharm.Pharmacol. 2009;61(9):1179-1186. PubMed
  22. Zutshi, R. K., Singh, R., Zutshi, U., Johri, R. K., and Atal, C. K. Influence of piperine on rifampicin blood levels in patients of pulmonary tuberculosis. J Assoc.Physicians India 1985;33(3):223-224.
  23. Marotta, R. B. and Floch, M. H. Diet and nutrition in ulcer disease. Med Clin North Am 1991;75(4):967-979. PubMed
  24. Subehan, Usia, T., Iwata, H., Kadota, S., and Tezuka, Y. Mechanism-based inhibition of CYP3A4 and CYP2D6 by Indonesian medicinal plants. J Ethnopharmacol. 5-24-2006;105(3):449-455. PubMed
  25. Gimenez L, Zacharisen M. Severe pepper allergy in a young child. WMJ. 2011 Jun;110(3):138-9.
  26. Ren T, Yang M, Xiao M, Zhu J, Xie W, Zuo Z. Time-dependent inhibition of carbamazepine metabolism by piperine in anti-epileptic treatment. Life Sci. 2019;218:314-323. PubMed
  27. Thomas AB, Choudhary DC, Raje A, Nagrik SS. Pharmacokinetics and pharmacodynamic herb-drug interaction of piperine with atorvastatin in rats. J Chromatogr Sci 2021;59(4):371-80. PubMed
  28. Haron MH, Dale O, Martin K, et al. Evaluation of the Herb-Drug Interaction Potential of Commonly Used Botanicals on the US Market with Regard to PXR- and AhR-Mediated Influences on CYP3A4 and CYP1A2. J Diet Suppl 2022. PubMed
  29. Lin F, Hu Y, Zhang Y, Zhao L, Zhong D, Liu J. Predicting Food-Drug Interactions between Piperine and CYP3A4 Substrate Drugs Using PBPK Modeling. Int J Mol Sci 2024;25(20):10955. PubMed

See these in context on the Black Pepper monograph →

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 →

Prickly Pear Cactus 9 references
  1. Meckes-Lozyoa M, Roman-Ramos R. Opuntia streptacantha; a coadjutor in the treatment of diabetes mellitus. Am J Chin Med 1986;14:116-8.
  2. Rayburn K, Martinez R, Escobedo M, et al. Glycemic effects of various species of nopal (Opuntia sp.) in type 2 diabetes mellitus. Texas J Rural Health 1998;26:68-76.
  3. Bush TM, Rayburn KS, Holloway SW, et al. Adverse interactions between herbal and dietary substances and prescription medications: a clinical survey. Altern Ther Health Med 2007;13:30-5.
  4. Sobieraj DM, Freyer CW. Probable hypoglycemic adverse drug reaction associated with prickly pear cactus, glipizide, and metformin in a patient with type 2 diabetes mellitus. Ann Pharmacother 2010;44:1334-7. PubMed
  5. Kleiner, O., Cohen, Z., and Mares, A. J. Low colonic obstruction due to Opuntia ficus indica seeds: the aftermath of enjoying delicious cactus fruits. Acta Paediatr. 2002;91(5):606-607.
  6. Steinberg, J. M. and Eitan, A. Prickly pear fruit bezoar presenting as rectal perforation in an elderly patient. Int J Colorectal Dis. 2003;18(4):365-367. PubMed
  7. Meckes-Lozyoa, M. and Roman-Ramos, R. Opuntia streptacantha: a coadjutor in the treatment of diabetes mellitus. Am J Chin Med 1986;14(3-4):116-118.
  8. Onakpoya IJ, O'Sullivan J, Heneghan CJ. The effect of cactus pear (Opuntia ficus-indica) on body weight and cardiovascular risk factors: a systematic review and meta-analysis of randomized clinical trials. Nutrition. 2015;31(5):640-6. PubMed
  9. Han EH, Lim MK, Lee S, et al. Efficacy of Ethanolic Extract of Opuntia ficus-indica var. saboten Stems for Improving Cognitive Function in Elderly Subjects 55-85 Years of Age: A Randomized, Double-Blind, Placebo-Controlled Study. J Med Food 2020;23(11):11

See these in context on the Prickly Pear Cactus 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 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 →

Garcinia 44 references
  1. Heymsfield SB, Allison DB, Vasselli JR, et al. Garcinia cambogia (hydroxycitric acid) as a potential antiobesity agent: a randomized controlled trial. JAMA 1998;280:1596-600. PubMed
  2. Soni MG, Burdock GA, Preuss HG, et al. Safety assessment of (-)-hydroxycitric acid and Super CitriMax, a novel calcium/potassium salt. Food Chem Toxicol 2004;42:1513-29. PubMed
  3. Stevens T, Qadri A, Zein NN. Two patients with acute liver injury associated with use of the herbal weight-loss supplement hydroxycut. Ann Intern Med 2005;142:477-8. PubMed
  4. Willis SL, Moawad FJ, Hartzell JD, et al. Hypertensive retinopathy associated with use of the ephedra-free weight-loss herbal supplement Hydroxycut. MedGenMed 2006;8:82.
  5. Preuss HG, Bagchi D, Bagchi M, et al. Effects of a natural extract of (-)-hydroxycitric acid (HCA-SX) and a combination of HCA-SX plus niacin-bound chromium and Gymnema sylvestre extract on weight loss. Diabetes Obes Metab 2004;6:171-180.
  6. Mansi IA, Huang J. Rhabdomyolysis in response to weight-loss herbal medicine. Am J Med Sci 2004;327:356-357. PubMed
  7. Lopez AM, Kornegay J, Hendrickson RG. Serotonin Toxicity Associated with Garcinia cambogia Over-the-counter Supplement. J Med Toxicol. 2014 Apr 4. [Epub ahead of print]. PubMed
  8. Michno A, Skibowska A, Raszeja-Specht A, Cwikowska J, Szutowicz A. The role of adenosine triphosphate citrate lyase in the metabolism of acetyl coenzyme a and function of blood platelets in diabetes mellitus. Metabolism 2004;53(1):66-72. PubMed
  9. Asghar M, Monjok E, Kouamou G, et al. Super CitriMax (HCA-SX) attenuates increases in oxidative stress, inflammation, insulin resistance, and body weight in developing obese Zucker rats. Mol Cell Biochem 2007;304(1-2):93-99. PubMed
  10. Wielinga PY, Wachters-Hagedoorn RE, Bouter B, et al. Hydroxycitric acid delays intestinal glucose absorption in rats. Am J Physiol Gastrointest Liver Physiol 2005;288(6):G1144-G1149. PubMed
  11. Leonhardt M, Balkan B, Langhans W. Effect of hydroxycitrate on respiratory quotient, energy expenditure, and glucose tolerance in male rats after a period of restrictive feeding. Nutrition 2004;20(10):911-915. PubMed
  12. Bunchorntavakul, C. and Reddy, K. R. Review article: herbal and dietary supplement hepatotoxicity. Aliment.Pharmacol.Ther 2013;37(1):3-17. PubMed
  13. Vasques CA, Schneider R, Klein-Júnior LC, et al. Hypolipemic effect of Garcinia Cambogia in obese women. Phytother Res 2014;28(6):887-91.
  14. Marquez F, Babio N, Bullo M, Salas-Salvado J. Evaluation of the safety and efficacy of hydroxycitric acid or Garcinia cambogia extracts in humans. Crit Rev Food Sci Nutr 2012;52:585-94.
  15. Allen SF, Godley RW, Evron JM, et al. Acute necrotizing eosinophilic myocarditis in a patient taking Garcinia cambogia extract successfully treated with high-dose corticosteroids. Can J Cardiol 2014;30(12):1732 e13-1732 e15. PubMed
  16. Dara L, Hewett J, Lim JK. Hydroxycut hepatotoxicity: a case series and review of liver toxicity from herbal weight loss supplements. World J Gastroenterol. 2008 Dec 7;14(45):6999-7004. PubMed
  17. Sharma T, Wong L, Tsai N, Wong RD. Hydroxycut(®) (herbal weight loss supplement) induced hepatotoxicity: a case report and review of literature. Hawaii Med J. 2010 Aug;69(8):188-90.
  18. Rashid NN, Grant J. Hydroxycut hepatotoxicity. Med J Aust. 2010 Feb 1;192(3):173-4. PubMed
  19. Actis GC, Bugianesi E, Ottobrelli A, Rizzetto M. Fatal liver failure following food supplements during chronic treatment with montelukast. Dig Liver Dis. 2007 Oct;39(10):953-5. PubMed
  20. Corey R, Werner KT, Singer A, Moss A, Smith M, Noelting J, Rakela J. Acute liver failure associated with Garcinia cambogia use. Ann Hepatol. 2016 Jan-Feb;15(1):123-6. PubMed
  21. Melendez-Rosado J, Snipelisky D, Matcha G, Stancampiano F. Acute hepatitis induced by pure Garcinia cambogia. J Clin Gastroenterol. 2015 May-Jun;49(5):449-50. PubMed
  22. García-Cortés M, Robles-Díaz M, Ortega-Alonso A, Medina-Caliz I, Andrade RJ. Hepatotoxicity by Dietary Supplements: A Tabular Listing and Clinical Characteristics. Int J Mol Sci. 2016 Apr 9;17(4):537. PubMed
  23. Dehoney S, Wellein M. Rhabdomyolysis associated with the nutritional supplement Hydroxycut. Am J Health Syst Pharm. 2009;66(2):142-8. PubMed
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See these in context on the Garcinia 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
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  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 →

Parts of this content are provided by the Therapeutic Research Center, LLC.

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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