Interactions on record — worth a quick check against your medications. Based on 10 of 11 ingredients. Check your meds →
Dietary supplement

Enz-Factors Plus Ingredients & Drug Interactions

by Douglas Laboratories

Enz-Factors Plus 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 Enz-Factors Plus 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

Enz-Factors Plus is a dietary supplement by Douglas Laboratories with 11 active ingredients. Its ingredients are commonly taken for high cholesterol, vitamin b3 deficiency (pellagra), heart health support.Based on those ingredients, 2,135 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Guar Gum, Niacin, Coenzyme Q-10. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Enz-Factors Plus by Douglas Laboratories

Ask about any prescription or over-the-counter medication and we check it for interactions with Enz-Factors Plus by Douglas Laboratories — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Enz-Factors Plus by Douglas Laboratories

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 13 of its 13 active ingredients.
  • “Mucopolysaccharides” is listed as a grouped ingredient — the label gives one combined amount (50 mg) without saying how much of each component you get.
  • “Lecithin” is listed as a grouped ingredient — the label gives one combined amount (400 mg) without saying how much of each component you get.

Enz-Factors Plus contains 13 active ingredients: niacin, carrageenan, guar gum, mucopolysaccharides, silicon dioxide, EDTA, L-carnitine, chondroitin sulfate, phosphatidylcholine, choline, coenzyme Q-10, phosphatidylethanolamine, phosphatidylinositol, and a bromelain/papain complex. The product also contains inactive ingredients (gelatin, silica, and vegetable stearate) as capsule material and binders.

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

This product doesn't appear to be marketed for a specific use, so we graded its ingredients' overall clinical evidence instead.

Strong

Strong clinical evidence supports its ingredients for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredients' overall clinical evidence instead.
  • On file: L-carnitine deficiency — rated "Effective" (L-carnitine) (Natural Medicines).
  • On file: Coenzyme Q10 deficiency — rated "Likely Effective" (Coenzyme Q10) (Natural Medicines).
  • On file: Pellagra — rated "Likely Effective" (Niacin) (Natural Medicines).
  • On file: Angina — rated "Possibly Effective" (L-carnitine) (Natural Medicines).
  • On file: Osteoporosis — rated "Possibly Effective" (Silicon) (Natural Medicines).

Evidence for this product's ingredients is mixed. Niacin is likely effective for pellagra and possibly effective for HIV/AIDS-related dyslipidemia and metabolic syndrome.

Guar gum is possibly effective for high cholesterol, high blood pressure, irritable bowel syndrome, and constipation. L-carnitine is effective for carnitine deficiency and possibly effective for high cholesterol, heart failure, and angina.

Chondroitin sulfate is possibly effective for cataracts and osteoarthritis. Coenzyme Q-10 is effective for CoQ-10 deficiency and possibly effective for fibromyalgia, migraines, heart failure, and diabetic nerve pain.

For carrageenan, phosphatidylcholine, choline, silicon dioxide, and the bromelain/papain complex, evidence is either insufficient or points toward ineffectiveness for their claimed uses—we hold no effectiveness data for EDTA or mucopolysaccharides in this product.

The evidence, ingredient by ingredient Niacin Carrageenan Guar Gum Chondroitin Sulfate Silicon L-carnitine Choline Coenzyme Q10

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 9 of the 9 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 9 of 9.
  • General safety write-ups exist for 9 of 9.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Most ingredients in this product are generally well tolerated in typical amounts. Niacin is the exception: while normal dietary amounts are safe, high-dose supplements can cause flushing (up to 70% of users), gastrointestinal upset, liver problems, and rare serious effects like myopathy (muscle disease) or vision changes.

Guar gum can cause bloating, gas, diarrhea, and abdominal cramps, especially at first—always take it with plenty of water to avoid intestinal blockage. L-carnitine may cause gastrointestinal upset and a fish-like body odor.

Chondroitin sulfate is generally well tolerated short-term but may occasionally cause skin symptoms or allergic reactions. Coenzyme Q-10 is well tolerated with minimal adverse effects in clinical studies.

Silicon dioxide carries occupational inhalation risks (silicosis) but is safe in oral supplement form. Phosphatidylcholine and choline may cause digestive upset at high doses.

Side effects, ingredient by ingredient Niacin Carrageenan Guar Gum Chondroitin Sulfate Silicon L-carnitine Choline Coenzyme Q10

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 9 matched ingredients can interact with medications — Choline, Carrageenan, Chondroitin Sulfate, Guar Gum, Niacin, among others.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications; heart-rhythm medications.
  • For scale: 2,136 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking Enz-Factors Plus, double-check these medication types with your doctor or pharmacist: blood thinners (anticoagulants like warfarin; antiplatelets), blood pressure medications, diabetes drugs, thyroid hormone replacement, statins (cholesterol drugs), gout medications (allopurinol and probenecid), bile acid sequestrants, antibiotics (especially penicillin), heart medications (digoxin), birth control pills containing ethinyl estradiol, and chemotherapy drugs—especially alkylating agents. These span moderate and minor interactions across niacin, guar gum, L-carnitine, chondroitin, and coenzyme Q-10.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

This product works best for people addressing niacin deficiency, high cholesterol, or heart-related conditions, since those ingredients have the strongest evidence. However, if you take blood pressure medications, blood thinners, diabetes drugs, thyroid hormone, gout drugs, statins, or oral antibiotics, you need to check each of your exact medications against the tool on this page before starting—niacin and several other ingredients in here interact with those drug classes.

Talk it over with your doctor or pharmacist before you add Enz-Factors Plus to your routine.

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

Assessment coverage: 9 of 13 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jun 1, 2012.

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 Enz-Factors Plus, straight from the product label.

Brand Douglas Laboratories
Barcode (UPC) 310539018538
Net contents 100 Capsule(s)
Market status On market
Date entered into DSLD Jun 1, 2012
DSLD ID 9849
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years), Dairy Free, Sugar 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 Enz-Factors Plus by Douglas Laboratories, 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:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
100
UPC/BARCODE
310539018538
IngredientAmount% DV
Niacin10 mg50%
Carrageenan50 mg--
Guar Gum50 mg--
Mucopolysaccharides50 mg--
Silicon Dioxide25 mg--
EDTA50 mg--
L-Carnitine75 mg--
Chondroitin Sulfate20 mg--
Phosphatidylcholine92 mg--
Choline40 mg--
Coenzyme Q-102.5 mg--
Phosphatidylethanolamine80 mg--
Phosphatidylinositol56 mg--
Lecithin400 mg--
Bromelain/Papain Complex40 mg--

Other ingredients: Gelatin, Silica, Vegetable Stearate

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

A Dietary Supplement

Formulation

This product contains NO yeast, wheat gluten, milk/dairy, corn, sodium, sugar, starch, artificial coloring, preservatives or flavoring.

Suggested/Recommended/Usage/Directions

Suggested Usage: As a dietary supplement, adults take 1 capsule daily or as directed by physician.

Precautions

KEEP OUT OF REACH OF CHILDREN.

Tamper resistant package, do not use if outer seal is missing.

Storage

For optimal storage conditions, store in a cool, dry place. (59(0)-77(0)F/15(0)-25(0)C) (35-65% relative humidity)

General

Formula #80414

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

See for yourself

Enz-Factors Plus by Douglas Laboratories label

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

Enz-Factors Plus 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 Enz-Factors Plus by Douglas Laboratories

These are the 11 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container100 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.

Niacin

Interacts with
727 drugs
10 mg per serving

Niacin (vitamin B3) is an essential nutrient your body needs for energy and metabolism, and deficiency is uncommon in most developed countries. Prescr...

Niacin monograph & interactions

Carrageenan

Interacts with
122 drugs
50 mg per serving

Carrageenan is a fiber-like substance taken from red seaweed and is mostly used as a thickener and gelling agent in foods. There is little solid human...

Carrageenan monograph & interactions

Guar Gum

Interacts with
2,025 drugs
50 mg 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...

Guar Gum monograph & interactions

Mucopolysaccharides

50 mg per serving

Silicon Dioxide

No known
interactions
25 mg per serving

Silicon is a trace mineral found in the body and in foods like oats, barley, and certain fruits and vegetables, and it is popular in supplements for h...

Silicon Dioxide monograph & interactions

EDTA

50 mg per serving

L-Carnitine

Interacts with
19 drugs
75 mg per serving

L-carnitine is a compound your body makes naturally and also gets from foods like meat. It helps cells turn fat into energy, and supplements are most...

L-Carnitine monograph & interactions

Choline

Interacts with
16 drugs
40 mg per serving

Choline is an essential nutrient your body needs for liver function, brain health, and nerve signaling, and many people get enough from foods like egg...

Choline monograph & interactions

Coenzyme Q-10

Interacts with
198 drugs
2.5 mg per serving

CoQ10 is a vitamin-like substance your body makes naturally that helps cells produce energy and acts as an antioxidant. It is generally well tolerated...

Coenzyme Q-10 monograph & interactions

Lecithin

No known
interactions
400 mg per serving Form: Soya

Lecithin is a natural fatty substance found in foods and made by the body that is widely used as a supplement and food emulsifier. Evidence supporting...

Lecithin monograph & interactions

Bromelain/Papain Complex

40 mg per serving

Other (inactive) ingredients: Gelatin, Silica, Vegetable Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Enz-Factors Plus by Douglas Laboratories Drug Interactions

Want to check YOUR meds against Enz-Factors Plus?

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
2,135Drugs
2,131 Moderate 4 Minor

Ingredients driving the most interactions

Guar Gum 2,025
Niacin 727
Coenzyme Q-10 198
Carrageenan 122
L-Carnitine 19

Individual Drug Interactions

The ingredients in Enz-Factors Plus interact with 2,135 drugs. Click any drug to see the details.

7 of the 11 ingredients in Enz-Factors Plus interact with drugs. Each result below shows which ingredient is responsible. Guar Gum Niacin Coenzyme Q-10 Carrageenan L-Carnitine Choline Chondroitin Sulfate

Each ingredient & the kinds of drugs it affects

For each ingredient in Enz-Factors Plus 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.

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
Guar Gum full monograph & interactions

Niacin15 drug types · 727 drugs

Alcohol (Ethanol)

Concomitant use of alcohol and niacin might increase the risk of flushing and hepatotoxicity.
Alcohol can exacerbate the flushing and pruritus associated with niacin. Large doses of niacin might also exacerbate liver dysfunction associated with chronic alcohol use. A case report describes delirium and lactic acidosis in a patient taking niacin 3 grams daily who ingested 1 liter of wine. Advise patients to avoid large amounts of alcohol while taking niacin.

Likelihood Probable Evidence D
Allopurinol (Zyloprim)

Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as allopurinol.
Large doses of niacin can reduce urinary excretion of uric acid, potentially resulting in hyperuricemia. Doses of uricosurics such as allopurinol might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.

Likelihood Probable Evidence C
Anticoagulant/Antiplatelet Drugs

Theoretically, niacin may have additive effects when used with anticoagulant or antiplatelet drugs.
Several cases of clotting factor synthesis deficiency and coagulopathy have been reported in patients taking sustained-release niacin. Also, thrombocytopenia has been reported in patients treated with niacin or niacin plus lovastatin.

Likelihood Possible Evidence D
Antidiabetes Drugs

Niacin can increase blood glucose levels and may diminish the effects of antidiabetes drugs.
Niacin impairs glucose tolerance in a dose-dependent manner, probably by causing or aggravating insulin resistance and increasing hepatic production of glucose. In diabetes patients, niacin 4.5 grams daily for 5 weeks can increase plasma glucose by an average of 16% and glycated hemoglobin (HbA1c) by 21%. However, lower doses of 1.5 grams daily or less appear to have minimal effects on blood glucose. In some patients, glucose levels increase when niacin is started, but then return to baseline when a stable dose is reached. Up to 35% of patients with diabetes may need adjustments in hypoglycemic therapy when niacin is added.

Likelihood Probable Evidence B
Antihypertensive Drugs

Theoretically, niacin may increase the risk of hypotension when used with antihypertensive drugs.
The vasodilating effects of niacin can cause hypotension. Furthermore, some clinical evidence suggests that a one-hour infusion of niacin can reduce systolic, diastolic, and mean blood pressure in hypertensive patients. This effect is not observed in normotensive patients.

Likelihood Possible Evidence B
Bile Acid Sequestrants

Bile acid sequestrants can bind niacin and decrease absorption. Separate administration by 4-6 hours to avoid an interaction.
In vitro studies show that colestipol (Colestid) binds about 98% of available niacin and cholestyramine (Questran) binds 10% to 30%.

Likelihood Possible Evidence D
Gemfibrozil (Lopid)

Theoretically, concomitant use of niacin and gemfibrozil might increase the risk of myopathy in some patients.
A case of myopathy from concomitant use of niacin and gemfibrozil has been reported. Niacin alone has also been associated with cases of myopathy. Using gemfibrozil with niacin might further increase the risk of developing myopathy.

Likelihood Possible Evidence D
Hepatotoxic Drugs

Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Niacin has been associated with cases of liver toxicity, especially when used in pharmacologic doses. Sustained-release niacin preparations appear to be associated with a higher risk of hepatotoxicity than immediate-release niacin.

Likelihood Possible Evidence D
Hmg-Coa Reductase Inhibitors ("Statins")

Theoretically, concomitant use of niacin and statins might increase the risk of myopathy and rhabdomyolysis in some patients.
Some case reports have raised concerns that niacin might increase the risk of myopathy and rhabdomyolysis when combined with statins. However, a significantly increased risk of myopathy has not been demonstrated in clinical trials, including those using an FDA-approved combination of lovastatin and niacin (Advicor).

Likelihood Possible Evidence D
Probenecid (Benemid)

Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as probenecid.
Large doses of niacin reduce urinary excretion of uric acid, potentially causing hyperuricemia. Doses of uricosurics such as probenecid might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.

Likelihood Probable Evidence C
Sulfinpyrazone (Anturane)

Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as sulfinpyrazone.
Large doses of niacin reduce urinary excretion of uric acid, potentially causing hyperuricemia. Doses of uricosurics such as sulfinpyrazone might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.

Likelihood Probable Evidence C
Thyroid Hormone

Theoretically, niacin might antagonize the therapeutic effects of thyroid hormones.
Clinical research and case reports suggests that taking niacin can reduce serum levels of thyroxine-binding globulin by up to 25% and moderately reduce levels of thyroxine (T4). Patients taking thyroid hormone for hypothyroidism might need dose adjustments when using niacin.

Likelihood Probable Evidence D
Transdermal Nicotine (Nicoderm)

Theoretically, concomitant use of niacin and transdermal nicotine might increase the risk of flushing and dizziness.
Niacin and nicotine can both cause flushing and dizziness.

Likelihood Possible Evidence D
Warfarin (Coumadin)

There is limited evidence that niacin may increase the anticoagulant effects of warfarin.
In a case report, a patient on warfarin developed an elevated international normalized ratio (INR) of 3.9 after taking niacin for two weeks. The patient's INR was previously stable, ranging between 2 and 3 in recent months, and no other medication changes were identified. The elevated INR returned to therapeutic range within 4 days following the discontinuation of niacin.

Likelihood Possible Evidence D
Aspirin

Large doses of aspirin might alter the clearance of niacin.
Aspirin is often used with niacin to reduce niacin-induced flushing. Doses of 80-975 mg aspirin have been used, but 325 mg appears to be optimal. Aspirin also seems to reduce the clearance of niacin by competing for glycine conjugation. Taking aspirin 1 gram seems to reduce niacin clearance by 45%. This is probably a dose-related effect and not clinically significant with the more common aspirin dose of 325 mg.

Likelihood Likely Evidence B
Niacin full monograph & interactions

Coenzyme Q-103 drug types · 198 drugs

Alkylating Agents

Coenzyme Q10 has antioxidant effects. Theoretically, this may reduce the activity of chemotherapy drugs that generate free radicals.
Theoretically, antioxidants such as coenzyme Q10 might protect tumor cells from chemotherapeutic agents that work by inducing oxidative stress, such as alkylating agents (e.g., cyclophosphamide) and radiation therapy. The clinical importance of this interaction is unknown.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Coenzyme Q10 is chemically similar to menaquinone and might have vitamin K-like procoagulant effects, which could decrease the effects of warfarin.
Concomitant use of coenzyme Q10 and warfarin might reduce the anticoagulant effects of warfarin. Four cases of decreased warfarin efficacy thought to be due to coenzyme Q10 have been reported. However, there is some preliminary clinical research that suggests coenzyme Q10 might not significantly decrease the effects of warfarin in patients who have a stable INR.

Likelihood Possible Evidence D
Antihypertensive Drugs

Theoretically, coenzyme Q10 might have additive effects with antihypertensive drugs.
Some clinical research shows that coenzyme Q10 can significantly lower blood pressure, although other studies have shown conflicting results.

Likelihood Possible Evidence B
Coenzyme Q-10 full monograph & interactions

Carrageenan1 drug type · 122 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, carrageenan may increase the risk of bleeding in patients taking anticoagulant or antiplatelet drugs.
Laboratory research suggests that carrageenan has anticoagulant effects. However, this has not been reported in humans.

Likelihood Possible Evidence D
Carrageenan full monograph & interactions

L-Carnitine3 drug types · 19 drugs

Acenocoumarol (Sintrom)

Theoretically, L-carnitine might increase the anticoagulant effects of acenocoumarol.
L-carnitine might enhance the anticoagulant effects of acenocoumarol, an oral anticoagulant similar to warfarin, but shorter-acting. There are at least two case reports of INR elevation with concomitant use. In one case, a 33-year-old male with a previously stable INR had an elevated INR of 4.65 after L-carnitine was started and continued for 10 weeks. INR normalized after discontinuation of the L-carnitine-containing product.

Likelihood Possible Evidence D
Thyroid Hormone

Theoretically, L-carnitine might decrease the effectiveness of thyroid hormone replacement.
L-carnitine appears to act as a peripheral thyroid hormone antagonist by inhibiting entry of thyroid hormone into the nucleus of cells. Taking L-carnitine also seems to diminish some of the symptoms of hyperthyroidism.

Likelihood Probable Evidence B
Warfarin (Coumadin)

Theoretically, L-carnitine might increase the anticoagulant effects of warfarin.
L-carnitine might increase the anticoagulant effects of acenocoumarol, a shorter-acting oral anticoagulant similar to warfarin. There is not enough information to know whether this interaction occurs with L-carnitine and warfarin.

Likelihood Possible Evidence D
L-Carnitine full monograph & interactions

Choline1 drug type · 16 drugs

Atropine

Theoretically, choline might decrease the effects of atropine in the brain.
Animal research shows that administering choline one hour before administering atropine can attenuate atropine-induced decreases in brain levels of acetylcholine. Theoretically, concomitant use of choline and atropine may decrease the effects of atropine.

Likelihood Possible Evidence D
Choline full monograph & interactions

Chondroitin Sulfate1 drug type · 2 drugs

Warfarin (Coumadin)

Taking chondroitin in combination with glucosamine might increase the anticoagulant effects of warfarin. However, the effect of chondroitin alone is unclear.
There have been multiple reports of increased international normalized ratio (INR) in patients taking warfarin with glucosamine, with or without chondroitin. The lack of reports with chondroitin alone seem to suggest that the interactions occurring in these reports may have been due to glucosamine. In two individual case reports, glucosamine/chondroitin combinations were associated with a significant increase in INR in patients previously stabilized on warfarin. Additionally, 20 voluntary case reports to the US Food & Drug Administration (FDA) have linked glucosamine plus chondroitin with increased INR, bruising, and bleeding in patients who were also taking warfarin. There have also been 20 additional case reports to the World Health Organization (WHO) that link glucosamine alone, without chondroitin, to increased INR in patients taking warfarin.

Likelihood Unlikely Evidence D
Chondroitin Sulfate full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Enz-Factors Plus, from the product label.

Douglas Laboratories

See all Douglas Laboratories products
Name
Douglas Laboratories
City
Pittsburgh
State
PA
ZipCode
15205
Web Address
www.douglaslabs.com
Pharmacist Counseling Corner

Enz-Factors Plus by Douglas Laboratories: Common Questions

Does Enz-Factors Plus by Douglas Laboratories interact with any medications?
Yes. Based on its ingredients, Enz-Factors Plus has a known interaction with 2,135 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Enz-Factors Plus contains 11 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.
Can I take this if I'm on warfarin or other blood thinners?
Not safely without checking first. Niacin, carrageenan, L-carnitine, chondroitin sulfate, and coenzyme Q-10 in this product all interact with blood thinners. Coenzyme Q-10 might actually reduce warfarin's effectiveness, while L-carnitine and chondroitin may increase bleeding risk. Talk to your doctor or pharmacist before starting.
Will this work for high cholesterol?
Possibly. Niacin is possibly effective for HIV/AIDS-related dyslipidemia, guar gum is possibly effective for high cholesterol, and L-carnitine is possibly effective for high cholesterol. Coenzyme Q-10 is included, though its cholesterol benefit is less established. The evidence is moderate, not strong.
What's the flushing I've heard about with niacin?
It's very common—up to 70% of people taking niacin experience it. Your face, arms, and chest get hot and tingly or itchy due to blood vessel dilation. It usually shows up even at low doses and can last 15 to 30 minutes. It's harmless but uncomfortable.
Is this safe during pregnancy?
Niacin at normal dietary amounts is likely safe in pregnancy, but high-dose supplements should be avoided unless prescribed. Data is limited for carrageenan during pregnancy. Silicon dioxide, guar gum, and chondroitin safety data is not complete for pregnancy, so talk with your doctor before taking any supplement while pregnant.
Can I take this with metformin for diabetes?
Not without checking first. Niacin can raise blood sugar and reduce how well diabetes drugs work, and guar gum may reduce metformin absorption. Talk to your doctor or pharmacist to see if this product is right for you if you're on diabetes medication.
What are the most common side effects?
Niacin causes flushing and stomach upset (nausea, heartburn, diarrhea). Guar gum causes bloating, gas, and diarrhea, especially at first. L-carnitine may cause stomach upset and a fish-like body odor. Coenzyme Q-10 and most other ingredients cause minimal side effects in typical doses.

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

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The Full Monographs Behind Enz-Factors Plus’s Ingredients

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

Herb & supplement monograph

Niacin

Interacts with 727 drugs

Niacin (vitamin B3) is an essential nutrient your body needs for energy and metabolism, and deficiency is uncommon in most developed countries. Prescription-strength niacin has been used to...

Read the full Niacin monograph → Herb & supplement monograph

Carrageenan

Interacts with 122 drugs

Carrageenan is a fiber-like substance taken from red seaweed and is mostly used as a thickener and gelling agent in foods. There is little solid human evidence supporting it as a health supp...

Read the full Carrageenan 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

Chondroitin Sulfate

Interacts with 2 drugs

Chondroitin sulfate is a naturally occurring building block of cartilage that is widely taken, often with glucosamine, for osteoarthritis joint pain. The evidence is mixed—some people report...

Read the full Chondroitin Sulfate monograph → Herb & supplement monograph

Silicon

Silicon is a trace mineral found in the body and in foods like oats, barley, and certain fruits and vegetables, and it is popular in supplements for hair, skin, nail, and bone health. Some s...

Read the full Silicon monograph → Herb & supplement monograph

L-carnitine

Interacts with 19 drugs

L-carnitine is a compound your body makes naturally and also gets from foods like meat. It helps cells turn fat into energy, and supplements are most clearly useful for people with a true ca...

Read the full L-carnitine monograph → Herb & supplement monograph

Choline

Interacts with 16 drugs

Choline is an essential nutrient your body needs for liver function, brain health, and nerve signaling, and many people get enough from foods like eggs, meat, and fish. Supplements may help...

Read the full Choline monograph → Herb & supplement monograph

Coenzyme Q10

Interacts with 198 drugs

CoQ10 is a vitamin-like substance your body makes naturally that helps cells produce energy and acts as an antioxidant. It is generally well tolerated and is most studied for heart condition...

Read the full Coenzyme Q10 monograph → Herb & supplement monograph

Lecithin

Lecithin is a natural fatty substance found in foods and made by the body that is widely used as a supplement and food emulsifier. Evidence supporting most of its health claims is limited, t...

Read the full Lecithin monograph → Herb & supplement monograph

Phosphatidylcholine

Phosphatidylcholine is a phospholipid that is part of every cell membrane and a source of choline. People take it for liver, brain, and gut health, but solid human evidence is limited for mo...

Read the full Phosphatidylcholine monograph →
Sources

Sources & How We Checked

Enz-Factors Plus'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 258 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.

Niacin 66 references
  1. Garg R, Malinow MR, Pettinger M, et al. Niacin treatment increases plasma homocysteine levels. Am Heart J 1999;138:1082-7.
  2. Anon. Inositol hexaniacinate. Altern Med Rev 1998;3:222-3.
  3. Knodel LC, Talbert RL. Adverse effects of hypolipidaemic drugs. Med Toxicol 1987;2:10-32. PubMed
  4. Guyton JR, Blazing MA, Hagar J, et al. Extended-release niacin vs gemfibrozil for the treatment of low levels of high-density lipoprotein cholesterol. Niaspan-Gemfibrozil Study Group. Arch Intern Med 2000;160:1177-84. PubMed
  5. Gibbons LW, Gonzalez V, Gordon N, Grundy S. The prevalence of side effects with regular and sustained-release nicotinic acid. Am J Med 1995;99:378-85. PubMed
  6. Whelan AM, Price SO, Fowler SF, Hainer BL. The effect of aspirin on niacin-induced cutaneous reactions. J Fam Pract 1992;34:165-8.
  7. Jungnickel PW, Maloley PA, Vander Tuin EL, et al. Effect of two aspirin pretreatment regimens on niacin-induced cutaneous reactions. J Gen Intern Med 1997;12:591-6. PubMed
  8. Capuzzi DM, Guyton JR, Morgan JM, et al. Efficacy and safety of an extended-release niacin (Niaspan): a long-term study. Am J Cardiol 1998;82:74-81;disc. 85U-6U. PubMed
  9. Gray DR, Morgan T, Chretien SD, Kashyap ML. Efficacy and safety of controlled-release niacin in dyslipoproteinemic veterans. Ann Intern Med 1994;121:252-8. PubMed
  10. McKenney JM, Proctor JD, Harris S, Chinchili VM. A comparison of the efficacy and toxic effects of sustained- vs immediate-release niacin in hypercholesterolemic patients. JAMA 1994;271:672-7. DOI
  11. Knopp RH, Alagona P, Davidson M, et al. Equivalent efficacy of a time-release form of niacin (Niaspan) given once-a-night versus plain niacin in the management of hyperlipidemia. Metabolism 1998;47:1097-104. PubMed
  12. Knopp RH. Clinical profiles of plain versus sustained-release niacin (Niaspan) and the physiologic rationale for nighttime dosing. Am J Cardiol 1998;82:24U-28U;discussion 39U-41U. PubMed
  13. Garg A, Grundy SM. Nicotinic acid as therapy for dyslipidemia in non-insulin-dependent diabetes mellitus. JAMA 1990;264:723-6. DOI
  14. Leighton RF, Gordon NF, Small GS, et al. Dental and gingival pain as side effects of niacin therapy. Chest 1998;114:1472-4. PubMed
  15. American Society of Health-System Pharmacists. ASHP Therapeutic Position Statement on the safe use of niacin in the management of dyslipidemias. Am J Health Syst Pharm 1997;54:2815-9. DOI
  16. Vega GL, Grundy SM. Lipoprotein responses to treatment with lovastatin, gemfibrozil, and nicotinic acid in normolipidemic patients with hypoalphalipoproteinemia. Arch Intern Med 1994;154:73-82. DOI
  17. Guyton JR, Goldberg AC, Kreisberg RA, et al. Effectiveness of once-nightly dosing of extended-release niacin alone and in combination for hypercholesterolemia. Am J Cardiol 1998;82:737-43.
  18. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  19. Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med 2001;345:1583-93. DOI
  20. Bays HE, Dujovne CA. Drug interactions of lipid-altering drugs. Drug Saf 1998;19:355-71. PubMed
  21. Rader JI, Calvert RJ, Hathcock JN. Hepatic toxicity of unmodified and time-release preparations of niacin. Am J Med 1992;92:77-81. PubMed
  22. Kahn SE, Beard JC, Schwartz MW, et al. Increased B-cell secretory capacity as mechanism for islet adaptation to nicotinic acid-induced insulin resistance. Diabetes 1989;38:562-8.
  23. Schwartz ML. Severe reversible hyperglycemia as a consequence of niacin therapy. Arch Int Med 1993;153:2050-2. DOI
  24. Raising HDL and Niacin Use. Pharmacist's Letter/Prescriber's Letter 2004;20(5):200504.
  25. McKenney J. New perspectives on the use of niacin in the treatment of lipid disorders. Arch Intern Med 2004;164:697-705. PubMed
  26. Reaven P, Witztum JL. Lovastatin, nicotinic acid and rhabdomyolysis (letter). Ann Int Med 1988;109:597-8. PubMed
  27. Ito MK. Advances in the understanding and management of dyslipidemia: using niacin-based therapies. Am J Health-Syst Pharm 2003;60(suppl 2):s15-21. PubMed
  28. Schwab RA, Bachhuber BH. Delirium and lactic acidosis caused by ethanol and niacin coingestion. Am J Emerg Med 1991;9:363-5. PubMed
  29. Product information: Niaspan. Kos Pharmaceuticals. Cranbury, NJ. 2005. Available at www.niaspan.com/professional/content/pdfs/productinfo.pdf. (Accessed 3 March 2006).
  30. Ding RW, Kolbe K, Merz B, et al. Pharmacokinetics of nicotinic acid-salicylic acid interaction. Clin Pharmacol Ther 1989;46:642-7. PubMed
  31. NIH News. NIH stops clinical trial on combination cholesterol treatment. May 26, 2011. http://www.nih.gov/news/health/may2011/nhlbi-26.htm. (Accessed 3 June 2011).
  32. Dearing BD, Lavie CJ, Lohmann TP, Genton E. Niacin-induced clotting factor synthesis deficiency with coagulopathy. Arch Intern Med. 1992;152(4):861-3. DOI
  33. O'Brien T, Silverberg JD, Nguyen TT. Nicotinic acid-induced toxicity associated with cytopenia and decreased levels of thyroxine-binding globulin. Mayo Clin Proc. 1992;67(5):465-8. PubMed
  34. Gadegbeku CA, Dhandayuthapani A, Shrayyef MZ, Egan BM. Hemodynamic effects of nicotinic acid infusion in normotensive and hypertensive subjects. Am J Hypertens. 2003;16(1):67-71. PubMed
  35. Garnett WR. Interactions with hydroxymethylglutaryl-coenzyme A reductase inhibitors. Am J Health Syst Pharm. 1995;52(15):1639-45. PubMed
  36. Litin SC, Anderson CF. Nicotinic acid-associated myopathy: a report of three cases. Am J Med. 1989;86(4):481-3. PubMed
  37. Dunn RT, Ford MA, Rindone JP, Kwiecinski FA. Low-Dose Aspirin and Ibuprofen Reduce the Cutaneous Reactions Following Niacin Administration. Am J Ther. 1995;2(7):478-480. PubMed
  38. Cashin-Hemphill L, Spencer CA, Nicoloff JT, et al. Alterations in serum thyroid hormonal indices with colestipol-niacin therapy. Ann Intern Med. 1987;107(3):324-9. PubMed
  39. Drinka PJ. Alterations in thyroid and hepatic function tests associated with preparations of sustained-release niacin. Mayo Clin Proc. 1992;67(12):1206. PubMed
  40. Shakir KM, Kroll S, Aprill BS, Drake AJ 3rd, Eisold JF. Nicotinic acid decreases serum thyroid hormone levels while maintaining a euthyroid state. Mayo Clin Proc. 1995;70(6):556-8. PubMed
  41. Etchason JA, Miller TD, Squires RW, et al. Niacin-induced hepatitis: a potential side effect with low-dose time-release niacin. Mayo Clin Proc. 1991;66(1):23-8. PubMed
  42. Henkin Y, Johnson KC, Segrest JP. Rechallenge with crystalline niacin after drug-induced hepatitis from sustained-release niacin. JAMA. 1990;264(2):241-3. DOI
  43. Henkin Y, Oberman A, Hurst DC, Segrest JP. Niacin revisited: clinical observations on an important but underutilized drug. Am J Med. 1991;91(3):239-46. PubMed
  44. Brown BG, Bardsley J, Poulin D, et al. Moderate dose, three-drug therapy with niacin, lovastatin, and colestipol to reduce low-density lipoprotein cholesterol <100 mg/dl in patients with hyperlipidemia and coronary artery disease. Am J Cardiol. 1997;80(2)
  45. Goldberg A, Alagona P Jr, Capuzzi DM, et al. Multiple-dose efficacy and safety of an extended-release form of niacin in the management of hyperlipidemia. Am J Cardiol. 2000;85(9):1100-5. PubMed
  46. Aronov DM, Keenan JM, Akhmedzhanov NM, et al. Clinical trial of wax-matrix sustained-release niacin in a Russian population with hypercholesterolemia. Arch Fam Med. 1996;5(10):567-75. PubMed
  47. Morgan JM, Capuzzi DM, Guyton JR, et al. Treatment Effect of Niaspan, a Controlled-release Niacin, in Patients With Hypercholesterolemia: A Placebo-controlled Trial. J Cardiovasc Pharmacol Ther. 1996;1(3):195-202. PubMed
  48. Andersson RG, Aberg G, Brattsand R, Ericsson E, Lundholm L. Studies on the mechanism of flush induced by nicotinic acid. Acta Pharmacol Toxicol (Copenh). 1977 Jul;41(1):1-10. PubMed
  49. Brown WV. Niacin for lipid disorders. Indications, effectiveness, and safety. Postgrad Med. 1995 Aug;98(2):185-9, 192-3. PubMed
  50. O'REILLY PO, CALLBECK MJ, HOFFER A. Sustained-release nicotinic acid (nicospan); effect on (1) cholesterol levels and (2) leukocytes. Can Med Assoc J. 1959;80(5):359-62.
  51. Gharavi AG, Diamond JA, Smith DA, Phillips RA. Niacin-induced myopathy. Am J Cardiol. 1994;74(8):841-2. PubMed
  52. Litin SC, Anderson CF. Nicotinic acid-associated myopathy: a report of three cases. Am J Med. 1989;86(4):481-3. PubMed
  53. Fraunfelder FW, Fraunfelder FT, Illingworth DR. Adverse ocular effects associated with niacin therapy. Br J Ophthalmol 1995;79:54-56. PubMed
  54. Ali EH, McJunkin B, Jubelirer S, Hood W. Niacin induced coagulopathy as a manifestation of occult liver injury. W V Med J. 2013 Jan-Feb;109(1):12-4
  55. Aramwit P, Srisawadwong R, Supasyndh O. Effectiveness and safety of extended-release nicotinic acid for reducing serum phosphorus in hemodialysis patients. J Nephrol. 2012 May-Jun;25(3):354-62. PubMed
  56. Bassan M. A case for immediate-release niacin. Heart Lung. 2012 Jan-Feb;41(1):95-8. PubMed
  57. Davidson MH, Rooney M, Pollock E, Drucker J, Choy Y. Effect of colesevelam and niacin on low-density lipoprotein cholesterol and glycemic control in subjects with dyslipidemia and impaired fasting glucose. J Clin Lipidol. 2013 Sep-Oct;7(5):423-32. PubMed
  58. Guyton JR, Fazio S, Adewale AJ, Jensen E, Tomassini JE, Shah A, Tershakovec AM. Effect of extended-release niacin on new-onset diabetes among hyperlipidemic patients treated with ezetimibe/simvastatin in a randomized controlled trial. Diabetes Care. 2012 PubMed
  59. Loebl T, Raskin S. A novel case report: acute manic psychotic episode after treatment with niacin. J Neuropsychiatry Clin Neurosci. 2013 Fall;25(4):E14. PubMed
  60. Teo KK, Goldstein LB, Chaitman BR, Grant S, Weintraub WS, Anderson DC, Sila CA, Cruz-Flores S, Padley RJ, Kostuk WJ, Boden WE; AIM-HIGH Investigators. Extended-release niacin therapy and risk of ischemic stroke in patients with cardiovascular disease: the
  61. Goldie C, Taylor AJ, Nguyen P, McCoy C, Zhao XQ, Preiss D. Niacin therapy and the risk of new-onset diabetes: a meta-analysis of randomized controlled trials. Heart. 2016 Feb;102(3):198-203.
  62. Schandelmaier S, Briel M, Saccilotto R, Olu KK, Arpagaus A, Hemkens LG, Nordmann AJ. Niacin for primary and secondary prevention of cardiovascular events. Cochrane Database Syst Rev. 2017 Jun 14;6:CD009744. PubMed
  63. Jenkins DJA, Spence JD, Giovannucci EL, et al. Supplemental vitamins and minerals for CVD prevention and treatment. J Am Coll Cardiol 2018;71(22):2570-84. PubMed
  64. Song S, Lee CJ, Oh J, Park S, Kang SM, Lee SH. Effect of Niacin on Carotid Atherosclerosis in Patients at Low-Density Lipoprotein-Cholesterol Goal but High Lipoprotein (a) Level: a 2-Year Follow-Up Study. J Lipid Atheroscler. 2019;8(1):58-66. PubMed
  65. Kimura H, Umemori Y, Yuki D. Anaphylactic shock-like symptoms due to niacin overdose: A case report. J Dermatol 2022;49(8):e287-e288. PubMed
  66. Nawaz N, Mistretta T, Karime C, Lewis J, Wolf E. Cholestatic Drug-Induced Liver Injury in a Patient Taking High-Dose Niacin for Hyperlipidemia. J Investig Med High Impact Case Rep 2024;12:23247096231224349. PubMed

See these in context on the Niacin monograph →

Carrageenan 6 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. Fetrow CW, Avila JR. Professional's Handbook of Complementary & Alternative Medicines. 1st ed. Springhouse, PA: Springhouse Corp., 1999.
  3. Coggins, C., Blanchard, K., Alvarez, F., Brache, V., Weisberg, E., Kilmarx, P. H., Lacarra, M., Massai, R., Mishell, D., Jr., Salvatierra, A., Witwatwongwana, P., Elias, C., and Ellertson, C. Preliminary safety and acceptability of a carrageenan gel for
  4. Tobacman, J. K., Wallace, R. B., and Zimmerman, M. B. Consumption of carrageenan and other water-soluble polymers used as food additives and incidence of mammary carcinoma. Med.Hypotheses 2001;56(5):589-598. PubMed
  5. Elias, C. J., Coggins, C., Alvarez, F., Brache, V., Fraser, I. S., Lacarra, M., Lahteenmaki, P., Massai, R., Mishell, D. R., Jr., Phillips, D. M., and Salvatierra, A. M. Colposcopic evaluation of a vaginal gel formulation of iota-carrageenan. Contracepti PubMed
  6. Laurie C, El-Zein M, Tota JE, et al. Efficacy of a carrageenan gel in preventing anal human papillomavirus (HPV) infection: interim analysis of the Lubricant Investigation in Men to Inhibit Transmission of HPV Infection (LIMIT-HPV) randomised controlled t

See these in context on the Carrageenan monograph →

Guar Gum 26 references
  1. Gin H, Orgerie MB, Aubertin J. The influence of Guar gum on absorption of metformin from the gut in healthy volunteers. Horm Metab Res 1989;21:81-3.
  2. Huupponen R, Seppala P, Iisalo E. Effect of guar gum, a fibre preparation, on digoxin and penicillin absorption in man. Eur J Clin Pharmacol 1984;26:279-81. PubMed
  3. Malo JL, Cartier A, L'Archeveque J, et al. Prevalence of occupational asthma and immunologic sensitization to guar gum among employees at a carpet-manufacturing plant. J Allergy Clin Immunol 1990;86:562-9. PubMed
  4. Lagier F, Cartier A, Somer J, et al. Occupational asthma caused by guar gum. J Allergy Clin Immunol 1990;85:785-90.
  5. Lewis JH. Esophageal and small bowel obstruction from guar gum-containing diet pills: analysis of 26 cases reported to the FDA. Am J Gastroenterol 1992;87:1424-8.
  6. Vuorinen-Markkola H, Sinisalo M, Koivisto VA. Guar gum in insulin-dependent diabetes: effects on glycemic control and serum lipoproteins. Am J Clin Nutr 1992;56:1056-1060. PubMed
  7. Superko HR, Haskell WL, Sawrey-Kubicek L, Farquhar JW. Effects of solid and liquid guar gum on plasma cholesterol and triglyceride concentrations in moderate hypercholesterolemia. Am J Cardiol 1988;62:51-5. PubMed
  8. 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
  9. Groop PH, Aro A, Stenman S, Groop L. Long-term effects of guar gum in subjects with non-insulin-dependent diabetes mellitus. Am J Clin Nutr 1993;58:513-8. PubMed
  10. Chuang LM, Jou TS, Yang WS, et al. Therapeutic effect of guar gum in patients with non-insulin-dependent diabetes mellitus. J Formos Med Assoc 1992;91:15-9.
  11. Ebeling P, Yki-Jarvinen H, Aro A, et al. Glucose and lipid metabolism and insulin sensitivity in type 1 diabetes: the effect of guar gum. Am J Clin Nutr 1988;48:98-103. PubMed
  12. Scheen AJ. Clinical pharmacokinetics of metformin. Clin Pharmacokinet 1996;30:359-71. PubMed
  13. Knopp RH, Superko HR, Davidson M, et al. Long-term blood cholesterol-lowering effects of a dietary fiber supplement. Am J Prev Med 1999;17:18-23. PubMed
  14. Patrick PG, Gohman SM, Marx SC, et al. Effect of supplements of partially hydrolyzed guar gum on the occurrence of constipation and use of laxative agents. J Am Diet Assoc 1998;98:912-4. PubMed
  15. Osterlund P, Ruotsalainen T, Korpela R, et al. Lactobacillus supplementation for diarrhoea related to chemotherapy of colorectal cancer: a randomised study. Br J Cancer 2007;97:1028-34. PubMed
  16. Lembcke B, Hasler K, Kramer P, et al. Plasma digoxin concentrations during administration of dietary fibre (guar gum) in man. Z Gastroenterol 1982;20;164-7.
  17. Riikonen, S., Savonius, H., Gylling, H., Nikkila, K., Tuomi, A. M., and Miettinen, T. A. Oral guar gum, a gel-forming dietary fiber relieves pruritus in intrahepatic cholestasis of pregnancy. Acta Obstet.Gynecol.Scand. 2000;79(4):260-264. DOI
  18. Kovacs, E. M., Westerterp-Plantenga, M. S., Saris, W. H., Goossens, I., Geurten, P., and Brouns, F. The effect of addition of modified guar gum to a low-energy semisolid meal on appetite and body weight loss. Int.J.Obes.Relat Metab Disord. 2001;25(3):307 PubMed
  19. Halama, W. H. and Mauldin, J. L. Distal esophageal obstruction due to a guar gum preparation (Cal-Ban 3000). South.Med.J. 1992;85(6):642-645. PubMed
  20. Landin, K., Holm, G., Tengborn, L., and Smith, U. Guar gum improves insulin sensitivity, blood lipids, blood pressure, and fibrinolysis in healthy men. Am.J.Clin.Nutr. 1992;56(6):1061-1065. PubMed
  21. Cicero, A. F., Derosa, G., Manca, M., Bove, M., Borghi, C., and Gaddi, A. V. Different effect of psyllium and guar dietary supplementation on blood pressure control in hypertensive overweight patients: a six-month, randomized clinical trial. Clin.Exp.Hyp PubMed
  22. Simons LA, Gayst S, Balasubramaniam S, Ruys J. Long-term treatment of hypercholesterolaemia with a new palatable formulation of guar gum. Atherosclerosis 1982;45:101-108. PubMed
  23. Salenius JP, Harju E, Jokela H, et al. Long term effects of guar gum on lipid metabolism after carotid endarterectomy. BMJ 1-14-1995;310:95-96. PubMed
  24. Gylling, H., Riikonen, S., Nikkila, K., Savonius, H., and Miettinen, T. A. Oral guar gum treatment of intrahepatic cholestasis and pruritus in pregnant women: effects on serum cholestanol and other non-cholesterol sterols. Eur.J.Clin.Invest 1998;28(5):35 PubMed
  25. Brillantino A, Iacobellis F, Izzo G, et al. Maintenance therapy with partially hydrolyzed guar gum in the conservative treatment of chronic anal fissure: results of a prospective, randomized study. Biomed Res Int 2014;2014:964942. PubMed
  26. Polymeros D, Beintaris I, Gaglia A, et al. Partially hydrolyzed guar gum accelerates colonic transit time and improves symptoms in adults with chronic constipation. Dig Dis Sci 2014;59(9):2207-14. PubMed

See these in context on the Guar Gum monograph →

Silicon 19 references
  1. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
  2. Jugdaohsingh R, Anderson SH, Tucker KL, et al. Dietary silicon intake and absorption. Am J Clin Nutr 2002;75:887-93. PubMed
  3. Ichiyanagi O, Sasagawa I, Adachi Y, et al. Silica urolithiasis without magnesium trisilicate intake. Urol Int 1998;61:39-42. PubMed
  4. Levison DA, Crocker PR, Banim S, Wallace DM. Silica stones in the urinary bladder. Lancet 1982;1:704-5. PubMed
  5. Lee MH, Lee YH, Hsu TH, et al. Silica stone--development due to long time oral trisilicate intake. Scand J Urol Nephrol 1993;27:267-9. PubMed
  6. Cruz Guerra, N. A., Gomez Garcia, M. A., Lovaco, Castellano F., Saez Garrido, J. C., Garcia, Cuerpo E., and Escudero, Barrilero A. [Silica urolithiasis: report of a new case]. Actas Urol.Esp 2000;24(2):202-204.
  7. Merget, R., Bauer, T., Kupper, H. U., Philippou, S., Bauer, H. D., Breitstadt, R., and Bruening, T. Health hazards due to the inhalation of amorphous silica. Arch Toxicol. 2002;75(11-12):625-634. PubMed
  8. Khuder, S. A., Peshimam, A. Z., and Agraharam, S. Environmental risk factors for rheumatoid arthritis. Rev Environ Health 2002;17(4):307-315. PubMed
  9. McLaughlin, J. K., Chow, W. H., and Levy, L. S. Amorphous silica: a review of health effects from inhalation exposure with particular reference to cancer. J Toxicol.Environ Health 4-25-1997;50(6):553-566. DOI
  10. Pelucchi, C., Pira, E., Piolatto, G., Coggiola, M., Carta, P., and La, Vecchia C. Occupational silica exposure and lung cancer risk: a review of epidemiological studies 1996-2005. Ann.Oncol. 2006;17(7):1039-1050. PubMed
  11. Gillissen, A., Gessner, C., Hammerschmidt, S., Hoheisel, G., and Wirtz, H. [Health significance of inhaled particles]. Dtsch.Med Wochenschr. 3-24-2006;131(12):639-644.
  12. Hu, J. F., Qu, H., and Wang, J. Z. [Meta analysis for relationship between exposure of free silicon dioxide and lung tumor]. Zhonghua Lao.Dong.Wei Sheng Zhi.Ye.Bing.Za Zhi. 2006;24(7):415-417.
  13. Jugdaohsingh, R. Silicon and bone health. J Nutr Health Aging 2007;11(2):99-110.
  14. Lacasse, Y., Martin, S., Gagne, D., and Lakhal, L. Dose-response meta-analysis of silica and lung cancer. Cancer Causes Control 2009;20(6):925-933. PubMed
  15. McCormic, Z. D., Khuder, S. S., Aryal, B. K., Ames, A. L., and Khuder, S. A. Occupational silica exposure as a risk factor for scleroderma: a meta-analysis. Int Arch Occup.Environ Health 2010;83(7):763-769. PubMed
  16. Haddad, F. S. and Kouyoumdjian, A. Silica stones in humans. Urol.Int 1986;41(1):70-76. PubMed
  17. Tervaert, J. W., Stegeman, C. A., and Kallenberg, C. G. Silicon exposure and vasculitis. Curr Opin.Rheumatol 1998;10(1):12-17. PubMed
  18. Steenland, K. and Stayner, L. Silica, asbestos, man-made mineral fibers, and cancer. Cancer Causes Control 1997;8(3):491-503. PubMed
  19. Boqué N, Valls RM, Pedret A, Puiggrós F, Arola L, Solà R. Relative absorption of silicon from different formulations of dietary supplements: a pilot randomized, double-blind, crossover post-prandial study. Sci Rep 2021;11(1):16479. PubMed

See these in context on the Silicon monograph →

L-carnitine 41 references
  1. Ellaway CM, Williams K, Leonard H, et al. Rett syndrome: randomized controlled trial of L-carnitine. J Child Neurol 1999;14:162-7. PubMed
  2. Anon. Carnitor (levocarnitine) package insert. Sigma-Tau Pharmaceuticals Inc, Gaithersburg, MD. December 1999.
  3. Cherchi A, Lai C, Angelino F, et al. Effects of L-carnitine on exercise tolerance in chronic stable angina: a multicenter, double-blind, randomized, placebo-controlled, crossover study. Int J Clin Pharmacol Ther Toxicol 1985;23:569-72.
  4. Plioplys AV, Plioplys S. Amantadine and L-carnitine treatment of Chronic Fatigue Syndrome. Neuropsychobiology 1997;35:16-23. PubMed
  5. Benvenga S, Ruggeri RM, Russo A, et al. Usefulness of L-carnitine, a naturally occurring peripheral antagonist of thyroid hormone action, in iatrogenic hyperthyroidism: a randomized, double-blind, placebo-controlled clinical trial. J Clin Endocrinol Meta
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  40. Hansen KS, Mogensen TH, Agergaard J, et al. High-dose coenzyme Q10 therapy versus placebo in patients with post COVID-19 condition: A randomized, phase 2, crossover trial. Lancet Reg Health Eur 2022. PubMed

See these in context on the Coenzyme Q10 monograph →

Lecithin 9 references
  1. Buchman AL, Dubin M, Jenden D, et al. Lecithin increases plasma free choline and decreases hepatic steatosis in long-term total parenteral nutrition patients. Gastroenterology 1992;102:1363-70.
  2. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  3. Chatellier G, Lacomblez L. Tacrine (tetrahydroaminoacridine; THA) and lecithin in senile dementia of the Alzheimer type: a multicentre trial. Groupe Francais d'Etude de la Tetrahydroaminoacridine. BMJ 1990;300:495-9.
  4. Gelenberg AJ, Dorer DJ, Wojcik JD, et al. A crossover study of lecithin treatment of tardive dyskinesia. J Clin Psychiatry 1990;51:149-53.
  5. Little A, Levy R, Chuaqui-Kidd P, Hand D. A double-blind, placebo controlled trial of high-dose lecithin in Alzheimer's disease. J Neurol Neurosurg Psychiatry 1985;48:736-42. PubMed
  6. Palm M, Moneret-Vautrin DA, Kanny G, et al. Food allergy to egg and soy lecithins. Allergy 1999;54:1116-7. PubMed
  7. Drachman DA, Glosser G, Fleming P, et al. Memory decline in the aged: treatment with lecithin and physostigmine. Neurology 1982;32:944-50. PubMed
  8. Gelenberg, A. J., Doller-Wojcik, J. C., and Growdon, J. H. Choline and lecithin in the treatment of tardive dyskinesia: preliminary results from a pilot study. Am J Psychiatry 1979;136(6):772-776. PubMed
  9. Electronic Code of Federal Regulations. Title 21, Chapter 1, Subchapter B, Part 184: Direct food substances affirmed as Generally Recognized as Safe. Subpart B - listing of specific substances affirmed as GRAS. Sec. 184.1400 Lecithin. Available at: https:

See these in context on the Lecithin 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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