Major interaction on record — check this product against your medications before combining. Based on 7 of 8 ingredients. Check your meds →
Dietary supplement

Essential Extra Fiber Ingredients & Drug Interactions

by The Cheat System Diet

Essential Extra Fiber label
See full label image
Powder Category: Other Combinations
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Essential Extra Fiber 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: Major

Essential Extra Fiber is a dietary supplement by The Cheat System Diet with 8 active ingredients. Its ingredients are commonly taken for constipation, diarrhea, high cholesterol.Based on those ingredients, 2,254 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Dietary Fiber, partially hydrolyzed Guar Gum, Green Tea Phytosome. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Essential Extra Fiber by The Cheat System Diet

Ask about any prescription or over-the-counter medication and we check it for interactions with Essential Extra Fiber by The Cheat System Diet — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Essential Extra Fiber by The Cheat System Diet

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 23, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 7 of its 7 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Essential Extra Fiber contains 7 ingredients total. The active components are soluble fiber, rice bran (a grain fiber with a small amount of protein and phytonutrients), green tea phytosome (a concentrated extract of green tea polyphenols), larch arabinogalactan (a plant-derived soluble fiber), partially hydrolyzed guar gum (a seed fiber that thickens and slows digestion), prune powder (dried plum), and pectin (a plant fiber from fruit).

The product contains no inactive fillers or other ingredients listed.

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: Digestive health and fiber support.
  • We looked for evidence on: Constipation, Diarrhea, Dyslipidemia, Hypercholesterolemia, Hyperlipidemia, Irritable bowel syndrome (IBS) — and 4 related terms.
  • The strongest evidence on file: Black Psyllium is rated "Effective" for Constipation (Natural Medicines).
  • Also on file: Pectin is rated "Possibly Effective" for Hypercholesterolemia.
  • Also on file: Rice Bran is rated "Possibly Effective" for Dyslipidemia.

The evidence for this product's ingredients is mixed and mostly modest. Rice bran is possibly effective for high cholesterol (dyslipidemia) but possibly ineffective for colorectal cancer prevention; evidence is insufficient to rate it for hair loss.

Green tea is rated likely effective for human papillomavirus (HPV) infection and possibly effective for high cholesterol and ovarian cancer. Guar gum is possibly effective for high blood pressure, high cholesterol, irritable bowel syndrome, and constipation.

Prune powder is possibly effective for constipation. For the other ingredients—larch arabinogalactan and pectin—evidence is either insufficient or absent in the data we hold.

Pectin is possibly effective for high cholesterol.

The evidence, ingredient by ingredient Black Psyllium Rice Bran Green Tea Larch Arabinogalactan Guar Gum Plum Pectin

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 7 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.

Rice bran is generally well tolerated as food, but concentrated supplement doses have limited safety data; expect possible digestive side effects like bloating, gas, and irregular bowel movements when you first increase fiber intake. Rice bran can rarely trigger allergic reactions including anaphylaxis in sensitive people.

Green tea beverage is generally well tolerated, but concentrated extracts—especially at high doses—have rarely caused liver injury; nausea, bloating, and digestive upset are more common with higher amounts. Guar gum and pectin are generally well tolerated but require adequate water intake to prevent choking or bowel blockage; both may cause gas, bloating, and loose stools.

Prune powder is generally considered safe in normal food amounts. For pregnancy and breastfeeding: rice bran is rated likely safe in pregnancy; green tea is rated possibly safe in pregnancy (though limit caffeine) and possibly safe during lactation; guar gum is possibly safe in pregnancy; prune powder, larch arabinogalactan, and pectin have insufficient data.

Talk with your doctor or pharmacist before using this product if you're pregnant or nursing.

Side effects, ingredient by ingredient Black Psyllium Rice Bran Green Tea Larch Arabinogalactan Guar Gum Plum Pectin

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 6 of the 7 matched ingredients can interact with medications — Black Psyllium, Pectin, Guar Gum, Green Tea, Larch Arabinogalactan, among others.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; diabetes medications; heart-rhythm medications; lithium.
  • For scale: 2,255 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 you start this product, check with your doctor or pharmacist if you take: beta-blockers like nadolol, cholesterol drugs such as atorvastatin or lovastatin, blood thinners or antiplatelet medications, seizure drugs (phenytoin, valproate, felbamate, ethosuximide), penicillin or tetracycline antibiotics, metformin for blood sugar, digoxin for heart rhythm, or ephedrine. Green tea's caffeine may also interact with these and other medications in ways we haven't fully documented; timing doses 30–60 minutes apart may help reduce some effects, but your own doctor is the best guide.

Check your own medication Run your meds through the checker above

The bottom line

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

This product is a multi-ingredient fiber blend that may help with constipation and cholesterol, but its green tea, guar gum, and pectin content can significantly reduce how your body absorbs or responds to many common medications—especially beta-blockers, cholesterol drugs, antibiotics, blood thinners, and seizure medications. If you take any prescription drugs, check each one against this product's ingredients using the tool on this page before you start.

Even if your medications don't appear to interact, talk with your doctor or pharmacist before adding it to your routine, especially if you're pregnant, breastfeeding, or have a history of allergies.

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

Assessment coverage: 7 of 7 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Oct 10, 2014.

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 Essential Extra Fiber, straight from the product label.

Brand The Cheat System Diet
Barcode (UPC) 693749005292
Net contents 11.6 oz.; 330 Gram(s)
Market status On market
Date entered into DSLD Oct 10, 2014
DSLD ID 37485
Product type Other Combinations
Supplement form Powder
Dietary claims / uses All Other
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 Essential Extra Fiber by The Cheat System Diet, 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 Level Scoop(s)
Maximum serving Sizes:
2 Level Scoop(s)
Servings per container
30
UPC/BARCODE
693749005292
IngredientAmount% DV
Calories45 {Calories}--
Total Carbohydrates10 Gram(s)3%
Sugar0 Gram(s)--
Calories from Fat0 {Calories}--
Dietary Fiber9 Gram(s)35%
Total Fat0 Gram(s)--
Soluble Fiber8 Gram(s)--
Rice Bran2.5 Gram(s)--
Green Tea Phytosome50 mg--
Arabinogalactan300 mg--
partially hydrolyzed Guar Gum8 Gram(s)--
Prune powder50 mg--
Pectin100 mg--

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.
FDA Statement of Identity

DIETARY SUPPLEMENT

Suggested/Recommended/Usage/Directions

Suggested Use: Mix 2 level scoops with 8-10 oz. of water, juice, or preferred beverage daily or as recommended by your health-care practitioner.

Formula

Contains ingredient derived from soy (phytosome).

Precautions

Contains ingredient derived from soy (phytosome).

Tamper Evident: Use only if bottle is sealed.

If pregnant, consult your health-care practitioner before using this product.

Formulation

This product is unflavored and unsweetened.

Storage

Store tightly sealed in a cool, dry place.

Brand IP Statement(s)

+This product uses Sunfiber(R) AG. Sunfiber AG is a registered trademark of Taiyo International, Inc. ++ResistAid(TM) This product uses Larch Arabinogalactan (ResistAid(TM)). ResistAid is a registered trademark of Lonza. +++This product uses Indena S.p.A.’s green tea phytosome (Greenselect(R)). Greenselect is a registered trademark of Indena S.p.A.

General

PTSP635_01

Seals/Symbols

ResistAid(TM)

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

See for yourself

Essential Extra Fiber by The Cheat System Diet label

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

Essential Extra Fiber 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 Essential Extra Fiber by The Cheat System Diet

These are the 8 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Level Scoop(s) Dosage formPowder Servings per container30 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.

Sugar

0 Gram(s) per serving

Dietary Fiber

Interacts with
2,025 drugs
9 Gram(s) per serving

Black psyllium is a soluble-fiber supplement made from the seeds of a Plantago plant, used mostly to ease constipation and support digestive health. I...

Dietary Fiber monograph & interactions
  • › Soluble Fiber

Rice Bran

No known
interactions
2.5 Gram(s) per serving

Rice bran is the nutrient-rich outer layer of the rice grain and is a good source of fiber, healthy fats, and plant compounds. It is most studied for...

Rice Bran monograph & interactions

Green Tea Phytosome

Interacts with
1,293 drugs
50 mg per serving Form: Camellia sinensis extract (leaf) decaffeinated, Phosphatidylcholine Complex

Green tea is a popular beverage rich in antioxidants called catechins, and drinking it in normal amounts is considered safe for most people. Concentra...

Green Tea Phytosome monograph & interactions

Arabinogalactan

Interacts with
121 drugs
300 mg per serving Form: Larch

Larch arabinogalactan is a soluble fiber from larch trees that is mainly used as a prebiotic and for immune support. Early research is interesting but...

Arabinogalactan monograph & interactions

Partially hydrolyzed Guar Gum

Interacts with
2,025 drugs
8 Gram(s) per serving

Guar gum is a soluble, gel-forming fiber from the guar bean that may modestly help with cholesterol, blood sugar, and bowel regularity. It is generall...

Partially hydrolyzed Guar Gum monograph & interactions

Prune powder

Interacts with
122 drugs
50 mg per serving

Plums and their dried form (prunes) are common, nutritious foods that are best known for helping relieve constipation thanks to their fiber and sorbit...

Prune powder monograph & interactions

Pectin

Interacts with
23 drugs
100 mg per serving Form: Apple

Pectin is a natural soluble fiber found in fruits like apples and citrus, and it is widely used in foods and as a fiber supplement. It may modestly he...

Pectin monograph & interactions
Interaction report

Essential Extra Fiber by The Cheat System Diet Drug Interactions

Want to check YOUR meds against Essential Extra Fiber?

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
2,254Drugs
13 Major 2,188 Moderate 53 Minor

Ingredients driving the most interactions

Dietary Fiber 2,025
partially hydrolyzed Guar Gum 2,025
Green Tea Phytosome 1,293
Prune powder 122
Arabinogalactan 121

Individual Drug Interactions

The ingredients in Essential Extra Fiber interact with 2,254 drugs. Click any drug to see the details.

6 of the 8 ingredients in Essential Extra Fiber interact with drugs. Each result below shows which ingredient is responsible. Dietary Fiber partially hydrolyzed Guar Gum Green Tea Phytosome Prune powder Arabinogalactan Pectin

Each ingredient & the kinds of drugs it affects

For each ingredient in Essential Extra Fiber 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.

Dietary Fiber7 drug types · 2,025 drugs

Carbamazepine (Tegretol)

Theoretically, black psyllium might reduce the effects of carbamazepine and increase the risk for convulsions.
Theoretically, black psyllium might reduce carbamazepine absorption. A preliminary study using blond psyllium reported decreased carbamazepine bioavailability due to binding of the drug to psyllium, as well as reduction of available fluid in the gut for dissolution of the drug. This interaction may also occur with black psyllium.

Likelihood Probable Evidence D
Lithium

Theoretically, taking black psyllium at the same time as lithium might reduce lithium absorption.
The fiber in black psyllium might reduce lithium absorption and plasma levels. Some case reports describe a reduction in plasma lithium levels with concomitant administration of blond psyllium. This was reversed when psyllium was stopped. This interaction may also occur with black psyllium.

Likelihood Probable Evidence D
Metformin (Glucophage)

Theoretically, black psyllium might increase the therapeutic and adverse effects of metformin.
Animal research shows that concurrent consumption of blond psyllium with metformin slows and increases the absorption of metformin. This interaction may also occur with black psyllium. To avoid changes in absorption, take psyllium 30-60 minutes after metformin.

Likelihood Possible Evidence D
Olanzapine (Zyprexa)

Theoretically, taking black psyllium at the same time as olanzapine might reduce olanzapine absorption.
The fiber in black psyllium might decrease the absorption of olanzapine. A single case report describes a reduction in the effectiveness of olanzapine when it was concomitantly administered with an unspecified type of psyllium 3 grams orally twice daily. This effect was reversed when psyllium was stopped.

Likelihood Possible Evidence D
Digoxin (Lanoxin)

Theoretically, taking black psyllium at the same time as digoxin might reduce digoxin absorption and decrease digoxin levels.
Psyllium might bind digoxin in the gut. However, some clinical evidence suggests that psyllium does not impact digoxin absorption.

Likelihood Unlikely Evidence B
Ethinyl Estradiol

Theoretically, taking black psyllium at the same time as ethinyl estradiol might alter levels of estradiol.
Concurrent use of blond psyllium with ethinyl estradiol results in a slight increase in the extent of ethinyl estradiol absorption and a slower rate of absorption. This is unlikely to be clinically significant.

Likelihood Unlikely Evidence D
Oral Drugs

Theoretically, psyllium might increase, decrease, or have no effect on the absorption of oral drugs.
Psyllium seems to have variable effects on drug absorption. To avoid changes in absorption, take psyllium 30-60 minutes after oral medications. Animal research shows that blond psyllium delays and increases the absorption of metformin and ethinyl estradiol. Case reports and animal research suggest that blond psyllium might reduce absorption of lithium, digoxin, olanzapine, and carbamazepine. Finally, some pharmacokinetic studies show that psyllium does not affect the absorption of levothyroxine or warfarin. Although many of these studies evaluated blond psyllium, the fiber content in black psyllium may have similar effects.

Likelihood Possible Evidence B
Dietary Fiber full monograph & interactions

partially hydrolyzed Guar Gum5 drug types · 2,025 drugs

Ethinyl Estradiol

Theoretically, guar gum might reduce the absorption of ethinyl estradiol, potentially decreasing its effectiveness.
Animal research shows that taking guar gum with ethinyl estradiol decreases ethinyl estradiol absorption. However, this effect has not been reported in humans.

Likelihood Possible Evidence D
Metformin (Glucophage)

Guar gum might reduce the absorption of metformin, potentially decreasing its effectiveness.
A small study in healthy volunteers shows that guar gum reduces the absorption rate of metformin.

Likelihood Probable Evidence B
Oral Drugs

Guar gum might reduce the absorption of some oral drugs, potentially decreasing their effectiveness.
Clinical research shows that guar gum reduces or slows absorption of medications such as penicillin and metformin. To avoid changes in absorption, take guar gum 30-60 minutes after oral medications.

Likelihood Possible Evidence B
Penicillin

Guar gum might reduce the absorption of penicillin, potentially decreasing its effectiveness.
A small clinical study in healthy volunteers shows that taking guar gum with penicillin results in decreased penicillin absorption and reduced penicillin levels.

Likelihood Probable Evidence B
Digoxin (Lanoxin)

Guar gum might slow digoxin absorption, but it does not seem to impact how much digoxin is absorbed overall.
Two small studies in healthy volunteers show no change in the overall extent of digoxin absorption, although early absorption was slowed, when taken with guar gum.

Likelihood Possible Evidence B
partially hydrolyzed Guar Gum full monograph & interactions

Green Tea Phytosome58 drug types · 1,293 drugs

Atorvastatin (Lipitor)

Green tea extract seems to reduce the levels and clinical effects of atorvastatin.
In healthy humans, taking green tea extract 300 mg or 600 mg along with atorvastatin reduces plasma levels of atorvastatin by approximately 24%. The elimination of atorvastatin is not affected. Atorvastatin is a substrate of organic anion-transporting polypeptides (OATPs). Research shows that two of the major catechins found in green tea, epicatechin gallate (ECG) and epigallocatechin gallate (EGCG), inhibit OATPs. Some OATPs are expressed in the small intestine and are responsible for the uptake of drugs and other compounds, which may have resulted in reduced plasma levels of atorvastatin. It is not clear if drinking green tea alters the absorption of atorvastatin.

Likelihood Likely Evidence B
Ephedrine

Theoretically, concomitant use might increase the risk for stimulant adverse effects.
Green tea contains caffeine. There is evidence that using ephedrine with caffeine might increase the risk of serious life-threatening or debilitating adverse effects such as hypertension, myocardial infarction, stroke, seizures, and death.

Likelihood Probable Evidence D
Nadolol (Corgard)

Green tea seems to reduce the levels and clinical effects of nadolol.
Preliminary clinical research shows that green tea consumption reduces plasma concentrations of nadolol. Compared to a control group, both peak levels and total drug exposure (AUC) of nadolol were reduced by approximately 85% in subjects who drank green tea daily for two weeks. Drinking green tea with nadolol also significantly reduced nadolol's systolic blood pressure lowering effect. Other clinical research shows that a single dose of green tea can affect plasma nadolol levels for at least one hour. Green tea catechins have been shown to inhibit organic anion transporting polypeptides (OATP), one of which, OATP1A2, is involved in the uptake of nadolol in the intestine The interaction is thought to be due primarily to the epigallocatechin gallate (EGCG) content of green tea.

Likelihood Likely Evidence B
5-Fluorouracil

Theoretically, high doses of green tea might increase the effects and side effects of 5-fluorouracil.
Animal research shows that taking green tea in amounts equivalent to about 6 cups daily in humans for 4 weeks prior to receiving a single injection of 5-fluorouracil increases the maximum plasma levels of 5-fluorouracil by about 2.5-fold and the area under the curve by 425%.

Likelihood Possible Evidence D
Adenosine (Adenocard)

Theoretically, green tea might decrease the vasodilatory effects of adenosine and interfere with its use prior to stress testing.
Green tea contains caffeine. Caffeine is a competitive inhibitor of adenosine at the cellular level. However, caffeine doesn't seem to affect supplemental adenosine because high interstitial levels of adenosine overcome the antagonistic effects of caffeine. It is recommended that methylxanthines and methylxanthine-containing products be stopped 24 hours prior to pharmacological stress tests. However, methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing.

Likelihood Possible Evidence B
Anticoagulant/Antiplatelet Drugs

Theoretically, green tea may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Conflicting reports exist regarding the effect of green tea on bleeding risk when used with anticoagulant or antiplatelet drugs; however, most evidence suggests that drinking green tea in moderate amounts is unlikely to cause a significant interaction. Green tea contains small amounts of vitamin K, approximately 7 mcg per cup. Some case reports have associated the antagonism of warfarin with the vitamin K content of green tea. However, these reports are rare, and very large doses of green tea (about 8-16 cups daily) appear to be needed to cause these effects. Furthermore, the catechins and caffeine in green tea are reported to have antiplatelet activity.

Likelihood Unlikely Evidence D
Beta-Adrenergic Agonists

Green tea contains caffeine. Theoretically, concomitant use of large amounts of caffeine might increase cardiac inotropic effects of beta-agonists.

Likelihood Probable Evidence D
Bortezomib (Velcade)

Theoretically, green tea might interfere with the effects of bortezomib.
In vitro research shows that green tea polyphenols, such as epigallocatechin gallate (EGCG), interact with bortezomib and block its proteasome inhibitory action. This prevents the induction of cell death in multiple myeloma or glioblastoma cancer cell lines. Advise patients taking bortezomib, not to take green tea.

Likelihood Possible Evidence D
Carbamazepine (Tegretol)

Theoretically, green tea might reduce the effects of carbamazepine and increase the risk for convulsions.
Green tea contains caffeine. Animal research suggests that taking caffeine can lower the anticonvulsant effects of carbamazepine and can induce seizures when taken in doses above 400 mg/kg. Human research has shown that taking caffeine 300 mg in three divided doses along with carbamazepine 200 mg reduces the bioavailability of carbamazepine by 32% and prolongs the plasma half-life of carbamazepine 2-fold in healthy individuals.

Likelihood Possible Evidence D
Celiprolol (Celicard)

Theoretically, green tea might reduce the levels and clinical effects of celiprolol.
In a small human study, taking green tea daily for 4 days appears to decrease blood and urine levels of celiprolol by at least 98%. This interaction is possibly due to the inhibition of organic anion transporting polypeptide (OATP). Green tea catechins have been shown to inhibit organic anion transporting polypeptides (OATP), one of which, OATP1A2, is found in the intestine The interaction is thought to be due primarily to the epigallocatechin gallate (EGCG) content of green tea.

Likelihood Possible Evidence D
Cimetidine (Tagamet)

Theoretically, concomitant use might increase the effects and adverse effects of caffeine in green tea.
Green tea contains caffeine. Cimetidine can reduce caffeine clearance by 31% to 42%.

Likelihood Likely Evidence B
Clozapine (Clozaril)

Theoretically, green tea might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.
Animal research suggests that, although green tea extract does not affect the elimination of clozapine, it delays the time to reach peak concentration and reduces the peak plasma levels. Also, concomitant administration of green tea and clozapine might theoretically cause acute exacerbation of psychotic symptoms due to the caffeine in green tea. Caffeine can increase the effects and toxicity of clozapine. Caffeine doses of 400-1000 mg daily inhibit clozapine metabolism. Clozapine is metabolized by cytochrome P450 1A2 (CYP1A2). Researchers speculate that caffeine might inhibit CYP1A2. However, there is no reliable evidence that caffeine affects CYP1A2. There is also speculation that genetic factors might make some patients be more sensitive to the interaction between clozapine and caffeine.

Likelihood Possible Evidence B
Contraceptive Drugs

Theoretically, concomitant use might increase the effects and adverse effects of caffeine found in green tea.
Green tea contains caffeine. Oral contraceptives can decrease caffeine clearance by 40% to 65%.

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

Theoretically, concomitant use might increase the levels and adverse effects of caffeine.
Green tea contains caffeine. Caffeine is metabolized by cytochrome P450 1A2 (CYP1A2),. Theoretically, drugs that inhibit CYP1A2 may decrease the clearance rate of caffeine from green tea and increase caffeine levels.

Likelihood Possible Evidence D
Dipyridamole (Persantine)

Theoretically, green tea might decrease the vasodilatory effects of dipyridamole and interfere with its use prior to stress testing.
Green tea contains caffeine. Caffeine might inhibit dipyridamole-induced vasodilation. It is recommended that methylxanthines and methylxanthine-containing products be stopped 24 hours prior to pharmacological stress tests. Methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing.

Likelihood Probable Evidence B
Disulfiram (Antabuse)

Theoretically, disulfiram might increase the risk of adverse effects from caffeine.
In human research, disulfiram decreases the clearance and increases the half-life of caffeine.

Likelihood Probable Evidence B
Diuretic Drugs

Theoretically, using green tea with diuretic drugs might increase the risk of hypokalemia.
Green tea contains caffeine. In excessive amounts, caffeine can reduce potassium levels due to stimulation of the sodium-potassium pump. Diuretics can also cause lower potassium levels.

Likelihood Possible Evidence D
Estrogens

Theoretically, estrogens might increase the levels and adverse effects of caffeine.
Green tea contains caffeine. Estrogen inhibits caffeine metabolism.

Likelihood Probable Evidence B
Ethosuximide (Zarontin)

Theoretically, green tea might reduce the effects of ethosuximide and increase the risk for convulsions.
Green tea contains caffeine. Animal research suggests that caffeine 92.4 mg/kg can decrease the anticonvulsant activity of ethosuximide. However, this effect has not been reported in humans.

Likelihood Possible Evidence D
Felbamate (Felbatol)

Theoretically, green tea might reduce the effects of felbamate and increase the risk for convulsions.
Green tea contains caffeine. Animal research suggests that a high dose of caffeine 161.7 mg/kg can decreases the anticonvulsant activity of felbamate. However, this effect has not been reported in humans.

Likelihood Possible Evidence D
Fexofenadine (Allegra)

Green tea can decrease blood levels of fexofenadine.
Clinical research shows that green tea can significantly decrease blood levels and excretion of fexofenadine. Taking green tea extract with a dose of fexofenadine decreased bioavailability of fexofenadine by about 30%. In vitro, green tea inhibits the cellular accumulation of fexofenadine by inhibiting the organic anion transporting polypeptide (OATP) drug transporter. Research shows that two of the major catechins found in green tea, epicatechin gallate (ECG) and epigallocatechin gallate (EGCG), inhibit OATPs, specifically OATP1A2, OATP1B1, and OATP2B1. In addition, green tea has been shown to reduce the absorption of some drugs that are OATP substrates.

Likelihood Probable Evidence B
Flutamide (Eulexin)

Theoretically, green tea might increase the levels and adverse effects of flutamide.
Green tea contains caffeine. In vitro evidence suggests that caffeine can inhibit the metabolism of flutamide. Theoretically, concomitant use of caffeine and flutamide might increase serum concentrations of flutamide and increase the risk adverse effects.

Likelihood Possible Evidence D
Fluvoxamine (Luvox)

Theoretically, fluvoxamine might increase the levels and adverse effects of caffeine.
Green tea contains caffeine. Fluvoxamine reduces caffeine metabolism.

Likelihood Probable Evidence D
Hepatotoxic Drugs

Theoretically, concomitant use might have additive adverse hepatotoxic effects.
Green tea extract supplements have been linked to several cases of hepatotoxicity and might have additive hepatotoxic effects with other drugs..

Likelihood Unlikely Evidence D
Imatinib (Gleevec)

Theoretically, green tea might reduce the levels and clinical effects of imatinib.
In animal research, a single dose of green tea extract reduces the area under the curve (AUC) of imatinib by up to approximately 64% and its main metabolite N-desmethyl imatinib by up to approximately 81%. This interaction has not been shown in humans. The mechanism of action is unclear but may involve multiple pathways.

Likelihood Possible Evidence D
Green Tea Phytosome full monograph & all 58 interactions

Prune powder1 drug type · 122 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, plum juice might have antiplatelet effects.
Consuming plum juice while taking anticoagulant or antiplatelet drugs might increase the risk of bruising and bleeding. In healthy volunteers, drinking plum juice 200 mL daily for 28 days prolonged clotting time and inhibited platelet aggregation.

Likelihood Possible Evidence B
Prune powder full monograph & interactions

Arabinogalactan1 drug type · 121 drugs

Immunosuppressants

Theoretically, larch arabinogalactan might interfere with immunosuppression therapy due to immunostimulant effects. Immunosuppressant drugs include azathioprine (Imuran), basiliximab (Simulect), cyclosporine (Neoral, Sandimmune), daclizumab (Zenapax), muromonab-CD3 (OKT3, Orthoclone OKT3), mycophenolate (CellCept), tacrolimus (FK506, Prograf), sirolimus (Rapamune), prednisone (Deltasone, Orasone), corticosteroids (glucocorticoids), and other drugs.

Likelihood Possible Evidence D
Arabinogalactan full monograph & interactions

Pectin3 drug types · 23 drugs

Digoxin (Lanoxin)

Theoretically, pectin might reduce the absorption of digoxin, potentially decreasing its effectiveness.
A small clinical study shows that taking digoxin with a kaolin-pectin suspension reduces the absorption of digoxin by about 62%. It is unclear if these effects are due to pectin, kaolin, or the combination.

Likelihood Possible Evidence B
Lovastatin (Mevacor)

Theoretically, pectin might reduce the absorption of lovastatin, potentially decreasing its effectiveness.
Case reports suggest that concomitant use of pectin and lovastatin might reduce the cholesterol-lowering effect of lovastatin, possibly due to reduced intestinal absorption of lovastatin.

Likelihood Possible Evidence D
Tetracycline Antibiotics

Theoretically, pectin might reduce the absorption of tetracycline antibiotics, potentially decreasing their effectiveness.
A small clinical study shows that taking tetracycline with bismuth subsalicylate in a kaolin-pectin suspension reduces the absorption of tetracycline by about 34%. It is unclear if these effects are due to pectin, kaolin, bismuth subsalicylate, or the combination.

Likelihood Possible Evidence B
Pectin full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Essential Extra Fiber, from the product label.

The Cheat System Diet

See all The Cheat System Diet products
Name
PEERtrainer, Inc.
Street Address
4440 PGA Blvd, Ste. 600
City
Palm Beach Gardens
State
FL
ZipCode
33410
Phone Number
(561) 623-5336
Pharmacist Counseling Corner

Essential Extra Fiber by The Cheat System Diet: Common Questions

Does Essential Extra Fiber by The Cheat System Diet interact with any medications?
Yes. Based on its ingredients, Essential Extra Fiber has a known interaction with 2,254 medications, including 13 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Essential Extra Fiber contains 8 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 fiber supplement make me go to the bathroom more?
Yes, that's likely—constipation is one of the conditions these ingredients are designed to help. You may also experience bloating, gas, or loose stools when you first increase your fiber intake, especially from the guar gum and rice bran. Start with a small dose and gradually increase it to let your digestive system adjust.
Does this have any caffeine in it?
Yes, through the green tea phytosome. Green tea contains caffeine, and that caffeine can interact with certain medications—especially seizure drugs, beta-blockers, and stimulants like ephedrine. If you're sensitive to caffeine or take any of those drugs, flag this product with your pharmacist before you use it.
Can I take this while pregnant or breastfeeding?
There isn't enough safety data on most of these ingredients during pregnancy and breastfeeding to give you a clear answer. Rice bran is rated likely safe in pregnancy, and green tea is rated possibly safe, but data for larch arabinogalactan, prune powder, and pectin are incomplete. Talk with your doctor or pharmacist about whether this product is right for you during pregnancy or while you're nursing.
Is this safe if I have a tree nut or seed allergy?
Rice bran has been reported to trigger allergic reactions including anaphylaxis in sensitive people, and rice bran proteins have been identified as a known allergen. Guar gum comes from a legume seed, and pectin can cause allergic reactions in some individuals. If you have a known allergy to nuts, seeds, or legumes, ask your pharmacist whether any of these ingredients pose a risk for you.
How much water should I drink with this?
The product contains guar gum, which absolutely requires plenty of water to work safely. Taking guar gum without enough fluid can cause serious blockage in your esophagus or small intestine. Drink at least 8 ounces of water with each dose, and more is better. Your doctor or the product label should specify the exact dose and water amount for this powder.
Will this lower my cholesterol or blood pressure?
Some of the ingredients—rice bran, green tea, and guar gum—have possibly effective ratings for high cholesterol, and guar gum is possibly effective for high blood pressure. However, these are modest effects, and the evidence is not strong. This product is not a substitute for prescribed cholesterol or blood-pressure medication. Talk with your doctor before using it alongside your other drugs.

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.

Essential Extra Fiber label
Go deeper

The Full Monographs Behind Essential Extra Fiber’s Ingredients

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

Herb & supplement monograph

Black Psyllium

Interacts with 2,025 drugs

Black psyllium is a soluble-fiber supplement made from the seeds of a Plantago plant, used mostly to ease constipation and support digestive health. It is best known and most studied for rel...

Read the full Black Psyllium monograph → Herb & supplement monograph

Rice Bran

Rice bran is the nutrient-rich outer layer of the rice grain and is a good source of fiber, healthy fats, and plant compounds. It is most studied for helping lower cholesterol, but for most...

Read the full Rice Bran monograph → Herb & supplement monograph

Green Tea

Interacts with 1,293 drugs

Green tea is a popular beverage rich in antioxidants called catechins, and drinking it in normal amounts is considered safe for most people. Concentrated green tea extracts are a different s...

Read the full Green Tea monograph → Herb & supplement monograph

Larch Arabinogalactan

Interacts with 121 drugs

Larch arabinogalactan is a soluble fiber from larch trees that is mainly used as a prebiotic and for immune support. Early research is interesting but limited, and most claims are not yet fi...

Read the full Larch Arabinogalactan monograph → Herb & supplement monograph

Guar Gum

Interacts with 2,025 drugs

Guar gum is a soluble, gel-forming fiber from the guar bean that may modestly help with cholesterol, blood sugar, and bowel regularity. It is generally safe in food amounts, but concentrated...

Read the full Guar Gum monograph → Herb & supplement monograph

Plum

Interacts with 122 drugs

Plums and their dried form (prunes) are common, nutritious foods that are best known for helping relieve constipation thanks to their fiber and sorbitol content. They are generally safe as f...

Read the full Plum monograph → Herb & supplement monograph

Pectin

Interacts with 23 drugs

Pectin is a natural soluble fiber found in fruits like apples and citrus, and it is widely used in foods and as a fiber supplement. It may modestly help with cholesterol, blood sugar, and di...

Read the full Pectin monograph →
Sources

Sources & How We Checked

Essential Extra Fiber'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 299 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.

Black Psyllium 18 references
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  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  3. Covington TR, et al. Handbook of Nonprescription Drugs. 11th ed. Washington, DC: American Pharmaceutical Association, 1996.
  4. Etman M. Effect of a bulk forming laxative on the bioavailablility of carbamazepine in man. Drug Dev Ind Pharm 1995;21:1901-6.
  5. Perlman BB. Interaction between lithium salts and ispaghula husk. Lancet 1990;335:416.
  6. Vaswani SK, Hamilton RG, Valentine MD, Adkinson NF. Psyllium laxative-induced anaphylaxis, asthma, and rhinitis. Allergy 1996;51:266-8. PubMed
  7. Lantner RR, Espiritu BR, Zumerchik P, Tobin MC. Anaphylaxis following ingestion of a psyllium-containing cereal. JAMA 1990;264:2534-6. DOI
  8. Kaplan MJ. Anaphylactic reaction to "Heartwise." N Engl J Med 1990;323:1072-3. DOI
  9. Nordstrom M, Melander A, Robertsson E, Steen B. Influence of wheat bran and of a bulk-forming ispaghula cathartic on the bioavailability of digoxin in geriatric in-patients. Drug Nutr Interact 1987;5:67-9..
  10. Robinson DS, Benjamin DM, McCormack JJ. Interaction of warfarin and nonsystemic gastrointestinal drugs. Clin Pharmacol Ther 1971;12:491-5. PubMed
  11. Garcia JJ, Fernandez N, Diez MJ, et al. Influence of two dietary fibers in the oral bioavailability and other pharmacokinetic parameters of ethinyloestradiol. Contraception 2000;62:253-7. PubMed
  12. Fernandez N, Lopez C, Díez R, et al. Drug interactions with the dietary fiber Plantago ovata husk. Expert Opin Drug Metab Toxicol 2012;8(11):1377-86.
  13. Semen plantaginis in: WHO Monographs on Selected Medicinal Plants, volume 1. World Health Organization, Geneva, 1999. Available at http://apps.who.int/medicinedocs/en/d/Js2200e/. Accessed November 26, 1026.
  14. Code of Federal Regulations, Title 21 (21CFR 101.17). Food labeling warning, notice, and safe handling statements. Available at www.ecfr.gov/cgi-bin/text-idx?SID=20f647d3b74161501f46564b915b4048&mc=true&node=se21.2.101_117&rgn=div8. Accessed December 3, 2
  15. Code of Federal Regulations, Title 21 (21CFR 201.319). Specific labeling requirements - water-soluble gums, hydrophilic gums, and hydrophilic mucilloids. Available at www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=201.319. Accessed Dece
  16. Diez R, Garcia JJ, Diez MJ, Sierra M, Sahagun AM, Fernandez N. Influence of Plantago ovata husk (dietary fiber) on the bioavailability and other pharmacokinetic parameters of metformin in diabetic rabbits. BMC Complement Altern Med. 2017 Jun 7;17(1):298. PubMed
  17. Chiu AC, Sherman SI. Effects of pharmacological fiber supplements on levothyroxine absorption. Thyroid. 1998;8(8):667-71. PubMed
  18. Merrick C, Madden CA, Capurso NA. A Case of Blunted Orally Disintegrating Olanzapine Effect Due to Coadministered Psyllium. J Clin Psychiatry 2021;82(2):20cr13633. PubMed

See these in context on the Black Psyllium monograph →

Rice Bran 7 references
  1. Covington TR, et al. Handbook of Nonprescription Drugs. 11th ed. Washington, DC: American Pharmaceutical Association, 1996.
  2. Fujiwaki T, Furusho K. The effects of rice bran broth bathing in patients with atopic dermatitis. Acta Paediatr Jpn 1992;34:505-10.
  3. Uenotsuchi T, Satoh E, Kiryu H, Yano Y. Pyemotes dermatitis caused by indirect contact with husk rice. Br J Dermatol 2000;143:680-2. DOI
  4. Satoh R, Tsuge I, Tokuda R, Teshima R. Analysis of the distribution of rice allergens in brown rice grains and of the allergenicity of products containing rice bran. Food Chem. 2019;276:761-767. PubMed
  5. Togashi Y, Inomata N, Suzuki A, Hakuta A, Aihara M. Pediatric case with rice bran allergy induced by epicutaneous sensitization in a family rice shop. Allergol Int. 2019;68(1):117-118. PubMed
  6. So WKW, Chan JYW, Law BMH, et al. Effects of a Rice Bran Dietary Intervention on the Composition of the Intestinal Microbiota of Adults with a High Risk of Colorectal Cancer: A Pilot Randomised-Controlled Trial. Nutrients 2021;13(2):526. PubMed
  7. Haneda Y, Kadowaki S, Furui M, Taketani T. A pediatric case of food-dependent exercise-induced anaphylaxis due to rice bran. Asia Pac Allergy 2021;11(1):e4. PubMed

See these in context on the Rice Bran monograph →

Green Tea 219 references
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  4. Healy DP, Polk RE, Kanawati L, et al. Interaction between oral ciprofloxacin and caffeine in normal volunteers. Antimicrob Agents Chemother 1989;33:474-8. PubMed
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Larch Arabinogalactan 8 references
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Guar Gum 26 references
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See these in context on the Guar Gum monograph →

Plum 10 references
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See these in context on the Plum monograph →

Pectin 11 references
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See these in context on the Pectin 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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