GI Guard Ingredients & Drug Interactions
What is this page for?
First and foremost: checking GI Guard 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
GI Guard is a dietary supplement by Protocol For Life Balance with 5 active ingredients. Its ingredients are commonly taken for zinc deficiency, immune support, cold symptoms.Based on those ingredients, 2,037 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Slippery Elm, Calcium, Zinc. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against GI Guard by Protocol For Life Balance
Ask about any prescription or over-the-counter medication and we check it for interactions with GI Guard by Protocol For Life Balance — and tell you which ingredient is responsible.
AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
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HelloPharmacist Scorecard of GI Guard by Protocol For Life Balance
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.
What’s inside
Full disclosure
GI Guard has 5 active ingredients. Calcium carbonate is the main source of supplemental calcium, which plays a role in bone health and various body functions.
Slippery elm inner bark is traditionally used for digestive comfort. Mastic gum powder and PepZin GI are included for gastrointestinal support.
The product also contains several inactive ingredients (microcrystalline cellulose, croscarmellose sodium, stearic acid, coating, silicon dioxide, and magnesium stearate) that serve as binders, fillers, and flow agents.
Does it work?
Strong evidence
Calcium carbonate is effective for kidney failure, indigestion (dyspepsia), low blood calcium (hypocalcemia), high potassium (hyperkalemia), and likely effective for osteoporosis. Mastic gum is possibly effective for indigestion.
Slippery elm has insufficient reliable evidence to support claims for cough, constipation, diarrhea, or inflammatory bowel disease (IBD) — the research we hold does not establish it works for these purposes. We have no effectiveness data on file for PepZin GI.
How safe is it?
Well-documented data
Calcium is generally well tolerated at recommended doses, though high amounts can cause constipation, diarrhea, stomach upset, belching, and flatulence. Rare serious concerns include kidney stones and calciphylaxis.
Some research raises questions about very high calcium intake (over 1500–2000 mg daily) and prostate cancer or heart disease risk, though the evidence is mixed and has been criticized. Slippery elm is generally well tolerated for short-term use, but high-quality safety data are limited.
Contact dermatitis and allergic reactions to its pollen have been reported. Mastic gum is generally well tolerated in food amounts, but supplement-strength safety data are limited; orally it may rarely cause nausea, diarrhea, or constipation.
We hold no safety data on PepZin GI.
Meds to double-check
Major interaction found
Before taking GI Guard, double-check if you're on HIV integrase inhibitors (dolutegravir or elvitegravir), the antibiotic ceftriaxone given intravenously, the blood thinner sotalol, levothyroxine for thyroid disease, raltegravir for HIV, diltiazem for the heart, or calcipotriene for psoriasis. Slippery elm may also slow absorption of oral medications in general.
Use the medication search tool below to confirm your prescriptions are safe with this product.
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.
GI Guard is worth considering if you need calcium and want digestive support — calcium has solid evidence for bone health and certain gastrointestinal uses. If you take HIV medications, thyroid hormone, heart medications, or certain antibiotics, check your exact drugs with the tool on this page before starting.
Talk to your pharmacist about the right timing and whether this product fits your health situation.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 3 of 5 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jan 23, 2025.
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
General information
Key facts about GI Guard, straight from the product label.
| Brand | Protocol For Life Balance |
|---|---|
| Barcode (UPC) | 707359133457 |
| Net contents | 60 Tablet(s) |
| Market status | On market |
| Date entered into DSLD | Jan 23, 2025 |
| DSLD ID | 326439 |
| Product type | Botanical With Nutrients |
| Supplement form | Tablet Or Pill |
| Dietary claims / uses | Nutrient, All Other, Structure/Function |
| Intended target group(s) | Vegan, Vegetarian, Adult (18 - 50 Years), Halal, Gluten Free, Dairy Free |
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 GI Guard by Protocol For Life Balance, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Zinc | 8 mg | 73% |
| Calcium | 70 mg | 5% |
| Calcium Carbonate | 206 mg | -- |
| Slippery Elm | 100 mg | -- |
| PepZin GI | 37.5 mg | -- |
| PepZin GI | 37.5 mg | -- |
| Mastic Gum, Powder | 100 mg | -- |
Other ingredients: Microcrystalline Cellulose, Croscarmellose Sodium, Stearic Acid, Coating, Silicon Dioxide, Magnesium Stearate
Tap any ingredient to jump to its full detail below.
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions
Suggested usage: Take 1 tablet twice daily, or as directed by your healthcare practitioner.
Formula
How it works: GI Guard is a formulation for GI health using the clinically validated ingredient, PepZin GI, a proprietary form of zinc complexed with carnosine. PepZin GI is slowly absorbed in the stomach, where it promotes normal mucous secretion, combats free radicals, and supports stable cell membranes. PepZin GI thereby helps to maintain the integrity of the stomach lining and its proper immune responses to the typically harsh gastric environment. Numerous clinical studies have demonstrated that PepZin GI can help to support GI health and promote gastric comfort.
Crescent H (Halal)
GI Guard with PepZin GI
Formulation
Cautions/Interactions: There are no known drug interactions.
Supports gastric health and comfort
Non-GMO
Vegetarian/Vegan
Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients.
Natural color variation may occur in this product.
FDA Disclaimer Statement
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
Seals/Symbols
Crescent H (Halal)
FDA Statement of Identity
A Dietary Supplement
Precautions
Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.
Brand IP Statement(s)
PepZin GI is a registered trademark of Hamari Chemicals, Ltd.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
GI Guard by Protocol For Life Balance label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
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)The Ingredients in GI Guard by Protocol For Life Balance
These are the 5 active ingredients this product is made of. Select any to open its full monograph.
Serving size1 Tablet(s) Dosage formTablet Or Pill Servings per container60 Amounts shown are per serving.
Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.
Zinc
Interacts with67 drugs
Zinc is an essential mineral that your body needs for immune function, wound healing, taste, and smell. Most people get enough from food, but suppleme...
Zinc monograph & interactions- › PepZin GI
Calcium
Interacts with168 drugs
Calcium is an essential mineral your body needs for strong bones, nerve signaling, and muscle function, and supplements can help fill gaps when diet f...
Calcium monograph & interactionsSlippery Elm
Interacts with2,022 drugs
Slippery elm is a traditional herbal remedy made from the inner bark of a North American elm tree, used mainly to soothe sore throats and irritated di...
Slippery Elm monograph & interactionsPepZin GI
Mastic Gum, Powder
No knowninteractions
Mastic is a resin from the mastic tree that has a long history of use for digestive complaints and oral health. Some small studies suggest it may help...
Mastic Gum, Powder monograph & interactionsOther (inactive) ingredients: Microcrystalline Cellulose, Croscarmellose Sodium, Stearic Acid, Coating, Silicon Dioxide, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.
GI Guard by Protocol For Life Balance Drug Interactions
HelloPharmacist Interaction Report
GI Guard by Protocol For Life Balance contains calcium carbonate, which interacts with several medications.
The most serious concern is with HIV integrase inhibitors — dolutegravir (Tivicay) and elvitegravir (Vitekta) — where calcium can cut blood levels by a significant amount. If you take either of these, separate doses by at least 2 hours before or 6 hours after calcium (or 2 hours after for elvitegravir).
Read the full breakdown — every affected drug type, severity by severity
Calcium also has Major-severity interactions with the antibiotic ceftriaxone (Rocephin) given intravenously — the two can form a dangerous precipitate in the lungs and kidneys, so avoid IV calcium within 48 hours of an IV ceftriaxone dose.
Moderate interactions occur with the blood thinner sotalol (Betapace), the thyroid hormone levothyroxine (Synthroid and others), the HIV drug raltegravir (Isentress), the heart medication diltiazem (Cardizem and others), and the psoriasis treatment calcipotriene (Dovonex). Slippery elm may also slow absorption of oral medications in general.
We could not check PepZin GI for interactions — we hold no data for it. Altogether, these interactions span 2,018 individual medications.
Use the search tool on this page to look up your exact prescriptions before starting.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against GI Guard?
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 checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in GI Guard interact with 2,037 drugs. Click any drug to see the details.
3 of the 5 ingredients in GI Guard interact with drugs. Each result below shows which ingredient is responsible. Slippery Elm Calcium Zinc
AcetylcholineMiochol-E
How Acetylcholine interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Acetylcholine interactionAcetylcysteine (prescription Drug)Cetylev, Legubeti
How Acetylcysteine (prescription Drug) interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Acetylcysteine (prescription Drug) interactionAcetylsalicylic AcidEntrophen
How Acetylsalicylic Acid interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Acetylsalicylic Acid interactionAcitretinSoriatane
How Acitretin interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Acitretin interactionAcrivastine, PseudoephedrineSemprex D
How Acrivastine, Pseudoephedrine interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Acrivastine, Pseudoephedrine interactionAcyclovirAvaclyr, Sitavig, Zovirax, Zovirax Injection
How Acyclovir interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Acyclovir interactionAdagrasibKrazati
How Adagrasib interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Adagrasib interactionAdalimumab-bwwdHadlima
How Adalimumab-bwwd interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Adalimumab-bwwd interactionAdefovirHepsera
How Adefovir interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Adefovir interactionAdenosineATP Tablets
How Adenosine interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Adenosine interactionAfatinib DimaleateGilotrif
How Afatinib Dimaleate interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Afatinib Dimaleate interactionAgomelatineValdoxan
How Agomelatine interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Agomelatine interactionAlbendazoleAlbenza
How Albendazole interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Albendazole interactionAlbuterolProAir HFA, Proventil, Ventolin (U.S.), Volmax
How Albuterol interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Albuterol interactionAlcuroniumAlcuronium
How Alcuronium interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Alcuronium interactionAlectinib HydrochlorideAlecensa
How Alectinib Hydrochloride interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Alectinib Hydrochloride interactionAlemtuzumabCampath
How Alemtuzumab interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Alemtuzumab interactionAlendronateBinosto, Fosamax
How Alendronate interacts with GI Guard — through 2 ingredients. Tap an ingredient for the detail:
Calcium CarbonateBisphosphonates Moderate
Interaction Summary
Calcium reduces the absorption of bisphosphonates.
Read the full Calcium Carbonate + Alendronate interactionSlippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Alendronate interactionAlendronate Sodium
How Alendronate Sodium interacts with GI Guard — through 2 ingredients. Tap an ingredient for the detail:
Calcium CarbonateBisphosphonates Moderate
Interaction Summary
Calcium reduces the absorption of bisphosphonates.
Read the full Calcium Carbonate + Alendronate Sodium interactionSlippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Alendronate Sodium interactionAlendronate Sodium, CholecalciferolFosamax Plus D
How Alendronate Sodium, Cholecalciferol interacts with GI Guard — through 2 ingredients. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Alendronate Sodium, Cholecalciferol interactionCalcium CarbonateBisphosphonates Moderate
Interaction Summary
Calcium reduces the absorption of bisphosphonates.
Read the full Calcium Carbonate + Alendronate Sodium, Cholecalciferol interactionAlfentanilAlfenta
How Alfentanil interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Alfentanil interactionAlfuzosinUroxatral
How Alfuzosin interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Alfuzosin interactionAlginic Acid, Aluminum HydroxideRafton
How Alginic Acid, Aluminum Hydroxide interacts with GI Guard — through 2 ingredients. Tap an ingredient for the detail:
Calcium CarbonateAluminum Moderate
Interaction Summary
Calcium citrate might increase aluminum absorption and toxicity.
Read the full Calcium Carbonate + Alginic Acid, Aluminum Hydroxide interactionSlippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Alginic Acid, Aluminum Hydroxide interactionAliskirenTekturna
How Aliskiren interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Aliskiren interactionAlitretinoinPanretin
How Alitretinoin interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Alitretinoin interactionAllopurinolCaplenal, Cosuric, Rimapurinol, Zyloprim, Zyloric
How Allopurinol interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Allopurinol interactionAlmotriptanAlmogran, Axert
How Almotriptan interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Almotriptan interactionAlogliptinNesina
How Alogliptin interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Alogliptin interactionAlogliptin, MetforminKazano
How Alogliptin, Metformin interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Alogliptin, Metformin interactionAlogliptin, PioglitazoneOseni
How Alogliptin, Pioglitazone interacts with GI Guard — through 1 ingredient. Tap an ingredient for the detail:
Slippery ElmOral Drugs Moderate
Interaction Summary
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Read the full Slippery Elm + Alogliptin, Pioglitazone interactionEach ingredient & the kinds of drugs it affects
For each ingredient in GI Guard 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.
Slippery Elm
Oral Drugs
Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Slippery elm inner bark contains mucilage, which may interfere with the absorption of orally administered drugs.
Calcium
Ceftriaxone (Rocephin)
Co-administration of intravenous calcium and ceftriaxone can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys.
Avoid administering intravenous calcium in any form, such as parenteral nutrition or Lactated Ringers, within 48 hours of intravenous ceftriaxone. Case reports in neonates show that administering intravenous ceftriaxone and calcium can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys. In several cases, neonates have died as a result of this interaction. So far there are no reports in adults; however, there is still concern that this interaction might occur in adults.
Dolutegravir (Tivicay)
Calcium seems to reduce levels of dolutegravir.
Advise patients to take dolutegravir either 2 hours before or 6 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium carbonate 1200 mg concomitantly with dolutegravir 50 mg reduces plasma levels of dolutegravir by almost 40%. Calcium appears to decrease levels of dolutegravir through chelation.
Elvitegravir (Vitekta)
Calcium seems to reduce levels of elvitegravir.
Advise patients to take elvitegravir either 2 hours before or 2 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium along with elvitegravir can reduce blood levels of elvitegravir through chelation.
Aluminum
Calcium citrate might increase aluminum absorption and toxicity. Other types of calcium do not increase aluminum absorption.
Calcium citrate can increase the absorption of aluminum when taken with aluminum hydroxide. The increase in aluminum levels may become toxic, particularly in individuals with kidney disease. However, the effect of calcium citrate on aluminum absorption is due to the citrate anion rather than calcium cation. Calcium acetate does not appear to increase aluminum absorption.
Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)
Calcium might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption when taken in a fasting state.
Advise patients that bictegravir/emtricitabine/tenofovir alafenamide and calcium can be taken together if taken with food. However, if taken on an empty stomach, bictegravir/emtricitabine/tenofovir alafenamide should not be taken with, or 2 hours after, calcium containing products.
Bisphosphonates
Calcium reduces the absorption of bisphosphonates.
Advise patients to take bisphosphonates at least 30 minutes before calcium, but preferably at a different time of day. Calcium supplements decrease absorption of bisphosphonates.
Calcipotriene (Dovonex)
Taking calcipotriene with calcium might increase the risk for hypercalcemia.
Calcipotriene is a vitamin D analog used topically for psoriasis. It can be absorbed in sufficient amounts to cause systemic effects, including hypercalcemia. Theoretically, combining calcipotriene with calcium supplements might increase the risk of hypercalcemia.
Digoxin (Lanoxin)
Using intravenous calcium with digoxin might increase the risk of fatal cardiac arrhythmias.
Hypercalcemia increases the risk of fatal cardiac arrhythmias with digoxin. However, one retrospective analysis of clinical data suggests that intravenous calcium does not increase the risk of dysrhythmias or mortality in patients receiving digoxin.
Diltiazem (Cardizem, Others)
Theoretically, calcium may reduce the therapeutic effects of diltiazem.
Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation. Theoretically, calcium might increase this risk of hypercalcemia and reduce the effectiveness of diltiazem.
Levothyroxine (Synthroid, Others)
Calcium seems to reduce the absorption and effectiveness of levothyroxine.
Advise patients to take levothyroxine and calcium supplements at least 4 hours apart. Calcium reduces levothyroxine absorption, probably by forming insoluble complexes. Calcium carbonate supplements reduce effectiveness of levothyroxine in patients with hypothyroidism.
Lithium
Theoretically, concomitant use of calcium and lithium may increase this risk of hypercalcemia.
Clinical research suggests that long-term use of lithium may cause hypercalcemia in 10% to 60% of patients. Theoretically, concomitant use of lithium and calcium supplements may further increase this risk.
Quinolone Antibiotics
Calcium seems to reduce the absorption of quinolone antibiotics.
Advise patients to take oral quinolones at least 2 hours before or 4-6 hours after calcium supplements or calcium-fortified foods. Taking calcium at the same time as oral quinolones can reduce quinolone absorption. Calcium binds to quinolones in the gut.
Raltegravir (Isentress)
Calcium may reduce levels of raltegravir.
Pharmacokinetic research shows that taking a single dose of calcium carbonate 3000 mg along with raltegravir 400 mg twice daily modestly decreases the mean area under the curve of raltegravir, but the decrease does not necessitate a dose adjustment of raltegravir. However, a case of elevated HIV-1 RNA levels and documented resistance to raltegravir has been reported for a patient taking calcium carbonate 1 gram three times daily plus vitamin D3 (cholecalciferol) 400 IU three times daily in combination with raltegravir 400 mg twice daily for 11 months. It is thought that calcium reduced raltegravir levels by chelation, leading to treatment failure.
Sotalol (Betapace)
Calcium seems to reduce the absorption of sotalol.
Advise patients to separate doses by at least 2 hours before or 4-6 hours after calcium. Calcium appears to reduce the absorption of sotalol, probably by forming insoluble complexes.
Tetracycline Antibiotics
Calcium seems to reduce the absorption of tetracycline antibiotics.
Advise patients to take oral tetracyclines at least 2 hours before, or 4-6 hours after calcium supplements. Taking calcium at the same time as oral tetracyclines can reduce tetracycline absorption. Calcium binds to tetracyclines in the gut.
Thiazide Diuretics
Taking calcium along with thiazides might increase the risk of hypercalcemia and renal failure.
Thiazides reduce calcium excretion by the kidneys. Using thiazides along with moderately large amounts of calcium carbonate increases the risk of milk-alkali syndrome (hypercalcemia, metabolic alkalosis, renal failure). Patients may need to have their serum calcium levels and/or parathyroid function monitored regularly.
Verapamil (Calan, Others)
Theoretically, calcium may reduce the therapeutic effects of verapamil.
Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation. Theoretically, use of calcium supplements may increase this risk of hypercalcemia and reduce the effectiveness of verapamil.
Calcium Channel Blockers
Intravenous calcium may decrease the effects of calcium channel blockers; oral calcium is unlikely to have this effect.
Intravenous calcium is used to decrease the effects of calcium channel blockers in the management of overdose. Intravenous calcium gluconate has been used before intravenous verapamil (Isoptin) to prevent or reduce the hypotensive effects without affecting the antiarrhythmic effects. But there is no evidence that dietary or supplemental calcium when taken orally interacts with calcium channel blockers.
Zinc
Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)
Theoretically, zinc might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption.
Advise patients that bictegravir/emtricitabine/tenofovir alafenamide should be taken at least 2 hours before or 6 hours after zinc containing products.
Cephalexin (Keflex)
Zinc might decrease cephalexin levels by chelating with cephalexin in the gut and preventing its absorption.
A pharmacokinetic study shows that zinc sulfate 250 mg taken concomitantly with cephalexin 500 mg decreases peak levels of cephalexin by 31% and reduces the exposure to cephalexin by 27%. Also, taking zinc sulfate 3 hours before cephalexin decreases peak levels of cephalexin by 11% and reduces the exposure to cephalexin by 18%. By decreasing cephalexin levels, zinc might increase the risk of treatment failure. This effect does not occur when zinc is taken 3 hours after the cephalexin dose. To avoid an interaction, advise patients take zinc sulfate 3 hours after taking cephalexin.
Cisplatin (Platinol-Aq)
Theoretically, zinc might interfere with the therapeutic effects of cisplatin.
Animal research suggests that zinc stimulates tumor cell production of the protein metallothionein, which binds and inactivates cisplatin. It is not known whether zinc supplements or high dietary zinc intake can cause clinically significant interference with cisplatin therapy. Cisplatin might also increase zinc excretion.
Integrase Inhibitors
Theoretically, taking zinc along with integrase inhibitors might decrease the levels and clinical effects of these drugs.
Zinc is a divalent cation. Pharmacokinetic studies have shown that other divalent cations such as calcium and iron can decrease blood levels of the integrase inhibitor dolutegravir through chelation.
Penicillamine (Cuprimine, Depen)
Zinc might reduce the levels and clinical effects of penicillamine.
By forming an insoluble complex with penicillamine, zinc interferes with penicillamine absorption and activity. Zinc supplements reduce the efficacy of low-dose penicillamine (0.5-1 gram/day), but do not seem to affect higher doses (1-2.75 gram/day), provided dosing times are separated. Advise patients to take zinc and penicillamine at least 2 hours apart.
Quinolone Antibiotics
Zinc can decrease the levels and clinical effects of quinolones antibiotics.
Quinolones form complexes with zinc in the gastrointestinal tract, reducing absorption of both the quinolone and zinc if taken at the same time. Advise patients to take these drugs at least 2 hours before, or 4-6 hours after, zinc supplements.
Ritonavir (Norvir)
Zinc modestly reduces levels of ritonavir.
Clinical research shows that zinc might reduce serum ritonavir levels by chelating with ritonavir in the gut and preventing its absorption. In patients with HIV, ritonavir is taken with atazanavir to prevent the metabolism and increase the effects of atazanavir. A pharmacokinetic study shows that, in patients being treated with atazanavir/ritonavir, co-administration of zinc sulfate (Solvazinc tablets) 125 mg as a single dose or as multiple daily doses for 2 weeks reduces plasma levels of ritonavir by about 16%. However, atazanavir levels still remains high enough to prevent HIV virus replication. Therefore, the decrease in ritonavir levels is not likely to be clinically significant.
Tetracycline Antibiotics
Zinc might reduce levels of tetracycline antibiotics.
Tetracyclines form complexes with zinc in the gastrointestinal tract, which can reduce absorption of both the tetracycline and zinc when taken at the same time. Taking zinc sulfate 200 mg with tetracycline reduces absorption of the antibiotic by 30% to 40%. Demeclocycline and minocycline cause a similar interaction. However, doxycycline does not seem to interact significantly with zinc. Advise patients to take tetracyclines at least 2 hours before, or 4-6 hours after, zinc supplements to avoid any interactions.
Amiloride (Midamor)
Amiloride can modestly reduce zinc excretion and increase zinc levels.
Clinical research shows that amiloride can reduce urinary zinc excretion, especially at doses of 10 mg per day or more. This zinc-sparing effect can help to counteract zinc losses caused by thiazide diuretics, but it is unlikely to cause zinc toxicity at usual amiloride doses. The other potassium-sparing diuretics, spironolactone (Aldactone) and triamterene (Dyrenium), do not seem to have a zinc-sparing effect.
Atazanavir (Reyataz)
Zinc modestly reduces levels of atazanavir, although this effect does not seem to be clinically significant.
Clinical research shows that zinc might decrease serum atazanavir levels by chelating with atazanavir in the gut and preventing its absorption. Although a single dose of zinc sulfate (Solvazinc tablets) 125 mg orally does not affect atazanavir concentrations in patients being treated with atazanavir/ritonavir, co-administration of zinc sulfate 125 mg daily for 2 weeks reduces plasma levels of atazanavir by about 22% in these patients. However, despite this decrease, atazanavir levels still remain at high enough concentrations for the prevention of HIV virus replication.
Brand information
Manufacturer and brand details for GI Guard, from the product label.
Protocol For Life Balance
See all Protocol For Life Balance products- Name
- Protocol For Life Balance
- Street Address
- 395 S. Glen Ellyn Rd.
- City
- Bloomingdale
- State
- IL
- ZipCode
- 60108
- Web Address
- protocolforlife.com
GI Guard by Protocol For Life Balance: Common Questions
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The Full Monographs Behind GI Guard’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Zinc
Interacts with 67 drugsZinc is an essential mineral that your body needs for immune function, wound healing, taste, and smell. Most people get enough from food, but supplements can help correct or prevent a defici...
Read the full Zinc monograph → Herb & supplement monographCalcium
Interacts with 168 drugsCalcium is an essential mineral your body needs for strong bones, nerve signaling, and muscle function, and supplements can help fill gaps when diet falls short. Most people do best getting...
Read the full Calcium monograph → Herb & supplement monographSlippery Elm
Interacts with 2,022 drugsSlippery elm is a traditional herbal remedy made from the inner bark of a North American elm tree, used mainly to soothe sore throats and irritated digestive tracts. Its mucilage can coat an...
Read the full Slippery Elm monograph → Herb & supplement monographMastic
Mastic is a resin from the mastic tree that has a long history of use for digestive complaints and oral health. Some small studies suggest it may help with indigestion, stomach ulcers, and d...
Read the full Mastic monograph →Sources & How We Checked
GI Guard'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.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
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 158 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.
Zinc 88 references
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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.
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