Interactions on record — worth a quick check against your medications. Based on 5 of 6 ingredients. Check your meds →
Dietary supplement

Homocysteine Shield Ingredients & Drug Interactions

by Country Life

Homocysteine Shield label
See full label image
Tablet Or Pill Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

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

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

The interaction bottom line Most serious interaction: Moderate

Homocysteine Shield is a dietary supplement by Country Life with 6 active ingredients. Its ingredients are commonly taken for morning sickness in pregnancy, premenstrual syndrome (pms), preventing or treating b6 deficiency.Based on those ingredients, 1,085 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Grape Skin Extract, Red Wine Extract, Vitamin B6. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Homocysteine Shield by Country Life

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

Pharmacist-reviewed data Checks every ingredient Answer in seconds
Prefer a human? Send your question to our licensed pharmacists — free, answered by email within 24 hours.

HelloPharmacist Scorecard of Homocysteine Shield by Country Life

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 Aug 6, 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 6 of its 6 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Homocysteine Shield contains six active ingredients. Vitamin B6, folic acid, and vitamin B12 are B-complex vitamins that work together to help manage homocysteine levels—an amino acid your body produces naturally.

Trimethylglycine is an amino acid derivative that supports this same function. Grape skin extract and red wine extract are plant-derived compounds that contribute additional support for cardiovascular health.

The tablet also contains several inactive ingredients (fillers and binders): cellulose, stearic acid, a cellulose and glycerin coating, silica, magnesium stearate, vanilla flavoring, and vegetable glaze.

Does it work?

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

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

Why this rating?
  • The label markets this product for: Support healthy homocysteine levels.
  • We looked for evidence on: Cardiovascular disease (CVD), Atherosclerosis, Hyperhomocysteinemia, Vascular health, Thrombosis risk.
  • The strongest evidence on file: Vitamin B6 is rated "Likely Effective" for Hyperhomocysteinemia (Natural Medicines).
  • Also on file: Vitamin B12 is rated "Possibly Effective" for Hyperhomocysteinemia.
  • Also on file: Resveratrol is rated "Possibly Ineffective" for Cardiovascular disease (CVD).

Vitamin B6 is effective for sideroblastic anemia and vitamin B6 deficiency, likely effective for high homocysteine levels (hyperhomocysteinemia), and possibly effective for pregnancy-related nausea and vomiting. Folic acid is effective for folate deficiency and likely effective for preventing neural tube birth defects and methotrexate-related toxicity; it's possibly effective for depression and cognitive impairment.

Vitamin B12 is effective for B12 deficiency and likely effective for cyanide poisoning, though the relevance of that use here is limited. For grape skin extract, the evidence shows it's possibly effective for chronic venous insufficiency (poor circulation in the legs) but possibly ineffective for chemotherapy-related nausea, hay fever, and obesity.

Red wine extract is possibly effective for obesity and hay fever but possibly ineffective for cardiovascular disease and high cholesterol. We hold no effectiveness data for trimethylglycine.

The evidence, ingredient by ingredient Vitamin B6 Folic Acid Vitamin B12 Grape Resveratrol

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 5 of the 5 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 5 of 5.
  • General safety write-ups exist for 5 of 5.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Vitamin B6 is generally well tolerated at doses under 100 mg daily, though high doses taken long-term can cause nerve damage (sensory neuropathy). Common side effects at normal doses include abdominal pain, headache, heartburn, and nausea.

Vitamin B6 is likely safe in pregnancy at recommended doses but possibly unsafe in pregnancy depending on the dose—talk with your doctor about what's right for you. It's likely safe while breastfeeding.

Folic acid is generally well tolerated at recommended doses. At higher doses (5 mg daily or more), it may cause abdominal cramps, diarrhea, and rash; at 15 mg daily, some people experience confusion, irritability, and sleep problems.

Folic acid is likely safe in pregnancy and lactation at standard prenatal doses. Grape skin extract and whole grapes are generally well tolerated, though concentrated supplements should be avoided in pregnancy due to limited safety data; avoid grape seed supplements while breastfeeding.

Red wine extract is possibly unsafe in pregnancy and should be avoided while breastfeeding due to insufficient safety information. Vitamin B12 is very safe and has no established upper limit; it's likely safe in both pregnancy and breastfeeding.

Side effects, ingredient by ingredient Vitamin B6 Folic Acid Vitamin B12 Grape Resveratrol

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?
  • 5 of the 5 matched ingredients can interact with medications — Resveratrol, Grape, Vitamin B12, Vitamin B6, Folic Acid.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; Parkinson's medications.
  • For scale: 1,086 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 Homocysteine Shield, double-check with your doctor or pharmacist if you take any seizure medications (phenobarbital, primidone, phenytoin), chemotherapy drugs (capecitabine, methotrexate, 5-fluorouracil), blood thinners or antiplatelet drugs, diabetes medications (metformin), cyclosporine, midazolam, the parasite medication pyrimethamine, the heart rhythm drug amiodarone, or levodopa for Parkinson's disease. These are Moderate-severity interactions—most are theoretical but some have been observed in research.

No interactions are documented for trimethylglycine among the ingredients we could check.

Check your own medication Run your meds through the checker above

The bottom line

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

This product may be worth considering if you're looking to manage homocysteine levels with B vitamins and plant extracts, particularly if you have a documented folate or B12 deficiency. However, if you take seizure medications (phenobarbital, primidone, phenytoin), diabetes medication (metformin), blood thinners, or any chemotherapy drugs, you'll need to talk this through carefully with your doctor or pharmacist before starting—several of these ingredients can interfere with how those medications work.

The same goes if you're pregnant or breastfeeding: some ingredients have safety concerns at certain doses, so get personalized guidance from your own healthcare provider.

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

Assessment coverage: 5 of 6 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Oct 25, 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 Homocysteine Shield, straight from the product label.

Brand Country Life
Barcode (UPC) 015794016236
Net contents 60 Tablet(s)
Market status On market
Date entered into DSLD Oct 25, 2012
DSLD ID 14050
Product type Other Combinations
Supplement form Tablet Or Pill
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Gluten Free, Dairy 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 Homocysteine Shield by Country Life, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
2 Tablet(s)
Maximum serving Sizes:
2 Tablet(s)
Servings per container
30
UPC/BARCODE
015794016236
IngredientAmount% DV
Vitamin B625 mg1250%
Folic Acid800 mcg200%
Vitamin B121000 mcg16667%
Trimethylglycine1000 mg--
Grape Skin Extract50 mg--
Red Wine Extract50 mg--

Other ingredients: Cellulose, Stearic Acid, Cellulose & Glycerin Coating, Silica, Magnesium Stearate, Vanilla, Vegetable Glaze

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.
Precautions

Do not accept if seal is broken.

Keep out of the reach of children.

If any adverse reactions occur, stop taking the product and consult your doctor.

WARNING: If you are pregnant or nursing, taking medication or planning a surgery, consult your doctor before using this product.

Formulation

NO: Yeast, wheat, gluten, milk, salt, preservatives or artificial color.

Gluten-Free

Seals/Symbols

Certified Vegan AVA(TM) American Vegetarian Association Certified GF(R) Gluten-Free Good Manufacturing Practices GMP CERTIFIED PLEASE RECYCLE (recycle) Our manufacturing supports wind power renewablechoice.com

General

Product No. 1623 05J11L

Storage

Store between 59(0)-86(0) F.

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.

General Statements

This product has been manufactured at an NSF GMP Registered facility.

A B vitamin complex to help support healthy homocysteine levels already within normal range Supports cardiovascular health

FDA Statement of Identity

Dietary Supplement

Formula

B VITAMINS

Suggested/Recommended/Usage/Directions

Directions: Adults take two (2) tablets daily with food or as directed by a health care professional. Do not exceed recommended dose. As a reminder, discuss the supplements and medications that you take with your health care providers.

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

See for yourself

Homocysteine Shield by Country Life label

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

Homocysteine Shield label

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

View the full label (PDF)
What’s inside

The Ingredients in Homocysteine Shield by Country Life

These are the 6 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Tablet(s) Dosage formTablet Or Pill Servings per container30 Amounts shown are per serving.

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

Vitamin B6

Interacts with
210 drugs
25 mg per serving Form: Pyridoxine Hydrochloride

Vitamin B6 (pyridoxine) is an essential water-soluble vitamin that your body needs for metabolism, brain function, and making red blood cells. It is b...

Vitamin B6 monograph & interactions

Folic Acid

Interacts with
40 drugs
800 mcg per serving

Folic acid is the man-made form of vitamin B9 and is one of the most well-studied supplements, especially for preventing serious birth defects when ta...

Folic Acid monograph & interactions

Vitamin B12

Interacts with
20 drugs
1000 mcg per serving Form: Cyanocobalamin

Vitamin B12 (cobalamin) is an essential nutrient your body needs to make red blood cells, keep nerves healthy, and support DNA. Supplements are very h...

Vitamin B12 monograph & interactions

Trimethylglycine

1000 mg per serving

Grape Skin Extract

Interacts with
910 drugs
50 mg per serving

Grapes and grape products like grape seed extract contain antioxidant compounds such as resveratrol and proanthocyanidins that may support heart and b...

Grape Skin Extract monograph & interactions

Red Wine Extract

Interacts with
822 drugs
50 mg per serving

Resveratrol is a plant compound found in red grapes, berries, and peanuts that is popular for heart health, anti-aging, and antioxidant support. While...

Red Wine Extract monograph & interactions

Other (inactive) ingredients: Cellulose, Stearic Acid, Cellulose & Glycerin Coating, Silica, Magnesium Stearate, Vanilla, Vegetable Glaze. These complete the product’s ingredient list but are not active constituents.

Interaction report

Homocysteine Shield by Country Life Drug Interactions

Want to check YOUR meds against Homocysteine Shield?

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

 Go to the checker
1,085Drugs
1,039 Moderate 46 Minor

Ingredients driving the most interactions

Grape Skin Extract 910
Red Wine Extract 822
Vitamin B6 210
Folic Acid 40
Vitamin B12 20

Individual Drug Interactions

The ingredients in Homocysteine Shield interact with 1,085 drugs. Click any drug to see the details.

5 of the 6 ingredients in Homocysteine Shield interact with drugs. Each result below shows which ingredient is responsible. Grape Skin Extract Red Wine Extract Vitamin B6 Folic Acid Vitamin B12

Each ingredient & the kinds of drugs it affects

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

Grape Skin Extract9 drug types · 910 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, grape extracts may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
In vitro evidence suggests that grape extracts might decrease platelet aggregation.

Likelihood Possible Evidence D
Cyclosporine (Neoral, Sandimmune)

Ingesting grape juice with cyclosporine can reduce cyclosporine absorption.
A small pharmacokinetic study in healthy young adults shows that intake of purple grape juice 200 mL along with cyclosporine can decrease the absorption of cyclosporine by up to 30% when compared with water. Separate doses of grape juice and cyclosporine by at least 2 hours to avoid this interaction.

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

Theoretically, grape juice might reduce the levels of CYP1A2 substrates.
A small pharmacokinetic study in healthy adults shows that ingestion of 200 mL of grape juice decreases phenacetin plasma levels. This is thought to be due to induction of CYP1A2.

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

Theoretically, grape seed extract may increase the levels of CYP2D6 substrates.
In vitro evidence suggests that grape seed extract might inhibit CYP2D6 enzymes. However, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2E1 (Cyp2E1) Substrates

Theoretically, grape seed extract might increase the levels of CYP2E1 substrates.
In vitro and animal research suggests that grape seed proanthocyanidin extract inhibits CYP2E1 enzymes. However, this interaction has not been reported in humans.

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

It is unclear if grape seed extract inhibits or induces CYP3A4; research is conflicting.
In vitro evidence suggests that grape seed extract might inhibit CYP3A4 enzymes. However, evidence from animal research shows that grape seed extract may induce CYP3A4 in the liver. So far, these interactions have not been reported in humans.

Likelihood Possible Evidence D
Midazolam (Versed)

Theoretically, long-term intake of grape seed extract might decrease the effects of midazolam.
Animal research shows that subchronic ingestions of grape seed extract can increase the elimination of intravenous midazolam by increasing hepatic CYP3A4 activity. Single doses of grape seed extract do not appear to affect midazolam elimination.

Likelihood Possible Evidence D
Phenacetin

Grape juice might decrease phenacetin absorption.
A small pharmacokinetic study in healthy adults shows that ingestion of 200 mL of grape juice decreases phenacetin plasma levels. This is thought to be due to induction of cytochrome P450 1A2 (CYP1A2).

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

It is unclear if grape juice or grape seed extract inhibits CYP2C9; research is conflicting.
In vitro evidence shows that grape seed extract or grape juice might inhibit CYP2C9 enzymes. However, a small pharmacokinetic study in healthy adults shows that drinking 8 ounces of grape juice once does not affect the clearance of flurbiprofen, a probe-drug for CYP2C9 metabolism. The effects of continued grape juice consumption are unclear.

Likelihood Unlikely Evidence D
Grape Skin Extract full monograph & interactions

Red Wine Extract5 drug types · 822 drugs

Anticoagulant/Antiplatelet Drugs

Resveratrol may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Resveratrol seems to have antiplatelet effects.

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

Theoretically, resveratrol might increase levels of drugs metabolized by CYP1A2.
In vitro research shows that resveratrol can inhibit CYP1A2 enzymes. However, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, resveratrol might increase levels of drugs metabolized by CYP2C19.
In vitro research shows that resveratrol can inhibit CYP2C19 enzymes. However, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2E1 (Cyp2E1) Substrates

Resveratrol might increase levels of drugs metabolized by CYP2E1.
In vitro research suggests that resveratrol inhibits CYP2E1 isoenzyme. Also, a pharmacokinetic study shows that taking resveratrol 500 mg daily for 10 days prior to taking a single dose of chlorzoxazone 250 mg increases the maximum concentration of chlorzoxazone by about 54%, the area under the curve of chlorzoxazone by about 72%, and the half-life of chlorzoxazone by about 35%. Chlorzoxazone is used as a probe drug for CYP2E1.

Likelihood Probable Evidence B
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
In vitro research shows that resveratrol can inhibit the CYP3A4 enzyme. However, clinical research shows that taking resveratrol 3000 mg daily for 8 weeks does not necessitate dose adjustments to medications metabolized by CYP3A4.

Likelihood Possible Evidence D
Red Wine Extract full monograph & interactions

Vitamin B65 drug types · 210 drugs

Amiodarone (Cordarone)

Theoretically, vitamin B6 might increase the photosensitivity caused by amiodarone.
Despite initial case reports suggesting that pyridoxine may have a protective effect against amiodarone-induced photosensitivity, preliminary clinical research suggests that pyridoxine may actually exacerbate this adverse effect.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, vitamin B6 may have additive effects when used with antihypertensive drugs.
Research in hypertensive rats shows that vitamin B6 can decrease systolic blood pressure. Similarly, clinical research in patients with hypertension shows that taking high doses of vitamin B6 may reduce systolic and diastolic blood pressure, possibly by reducing plasma levels of epinephrine and norepinephrine.

Likelihood Possible Evidence B
Phenobarbital (Luminal)

High doses of vitamin B6 may reduce the levels and clinical effects of phenobarbital.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenobarbital, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenobarbital to avoid high doses of vitamin B6.

Likelihood Possible Evidence D
Phenytoin (Dilantin)

High doses of vitamin B6 may reduce the levels and clinical effects of phenytoin.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenytoin, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenytoin to avoid high doses of vitamin B6.

Likelihood Possible Evidence D
Levodopa

Vitamin B6 may increase the metabolism of levodopa when taken alone, but not when taken in conjunction with carbidopa.
Vitamin B6 (pyridoxine) enhances the metabolism of levodopa, reducing its clinical effects. However, this interaction does not occur when carbidopa is used concurrently with levodopa (Sinemet). Therefore, it is not likely to be a problem in most people.

Likelihood Unlikely Evidence D
Vitamin B6 full monograph & interactions

Folic Acid7 drug types · 40 drugs

5-Fluorouracil

Theoretically, high doses of folic acid might increase the toxicity of 5-fluorouracil.
Increases in gastrointestinal side effects of 5-fluorouracil, such as stomatitis and diarrhea, have been described in two clinical studies when leucovorin, a form of folic acid, was administered with 5-fluorouracil.

Likelihood Possible Evidence D
Capecitabine (Xeloda)

Use of high-dose folic acid might contribute to capecitabine toxicity.
Clinical research suggests that higher serum folate levels are associated with an increased risk for moderate or severe toxicity during capecitabine-based treatment for colorectal cancer. Additionally, in one case report, taking folic acid 15 mg daily might have contributed to increased toxicity, including severe diarrhea, vomiting, edema, hand-foot syndrome, and eventually death, in a patient prescribed capecitabine.

Likelihood Possible Evidence D
Methotrexate (Trexall, Others)

Folic acid might reduce the efficacy of methotrexate as a cancer treatment when given concurrently.
Methotrexate exerts its cytotoxic effects by preventing conversion of folic acid to the active form needed by cells. There is some evidence that folic acid supplements reduce the efficacy of methotrexate in the treatment of acute lymphoblastic leukemia, and theoretically they could reduce its efficacy in the treatment of other cancers. Advise cancer patients to consult their oncologist before using folic acid supplements. In patients treated with long-term, low-dose methotrexate for rheumatoid arthritis (RA) or psoriasis, folic acid supplements can reduce the incidence of side effects, without reducing efficacy.

Likelihood Probable Evidence B
Phenobarbital (Luminal)

Folic acid might have antagonistic effects on phenobarbital and increase the risk for seizures.
Folic acid can have direct convulsant activity in some people, reversing the effects of phenobarbital and worsening seizure control. Monitor closely for increased seizure activity.

Likelihood Probable Evidence B
Phenytoin (Dilantin)

Folic acid might reduce serum levels of phenytoin in some patients.
Folic acid may be a cofactor in phenytoin metabolism. Folic acid, in doses of 1 mg daily or more, can reduce serum levels of phenytoin in some patients. Increases in seizure frequency have been reported. If folic acid supplements are added to established phenytoin therapy, monitor serum phenytoin levels closely. If phenytoin and folic acid are started at the same time and continued together, adverse changes in phenytoin pharmacokinetics are avoided. Note that phenytoin also reduces serum folate levels.

Likelihood Probable Evidence B
Primidone (Mysoline)

Folic acid might have antagonistic effects on primidone and increase the risk for seizures.
Folic acid can have direct convulsant activity in some people, reversing the effects of primidone and worsening seizure control. Monitor closely for increased seizure activity. Note that primidone also reduces serum folate levels.

Likelihood Probable Evidence B
Pyrimethamine (Daraprim)

Folic acid might antagonize the effects of pyrimethamine.
Folic acid can antagonize the antiparasitic effects of pyrimethamine against toxoplasmosis and Pneumocystis carinii pneumonia. Folic acid doesn't antagonize the effects of pyrimethamine in the treatment of malaria, because malarial parasites cannot use exogenous folic acid. Use folinic acid as an alternative to folic acid when indicated.

Likelihood Probable Evidence D
Folic Acid full monograph & interactions

Vitamin B121 drug type · 20 drugs

Metformin (Glucophage)

Metformin, a common medication used to manage type 2 diabetes, has been associated with lower vitamin B12 levels in some individuals. Prolonged use of metformin can interfere with the absorption of B12 in the digestive system, potentially leading to a deficiency in this essential vitamin.

Likelihood Possible Evidence A
Vitamin B12 full monograph & interactions
The maker

Brand information

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

Country Life

See all Country Life products
Name
Country Life, LLC
Street Address
180 Vanderbilt Motor Parkway
City
Hauppauge
State
NY
ZipCode
11788
Web Address
CountryLifeVitamins.com
Pharmacist Counseling Corner

Homocysteine Shield by Country Life: Common Questions

Does Homocysteine Shield by Country Life interact with any medications?
Yes. Based on its ingredients, Homocysteine Shield has a known interaction with 1,085 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Homocysteine Shield contains 6 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Is this safe to take if I'm pregnant?
Some ingredients have good safety data in pregnancy—vitamin B6 and folic acid at recommended doses are considered likely safe—but red wine extract should be avoided due to insufficient safety information. Vitamin B12 is needed and safe at normal amounts. Talk with your doctor or pharmacist about the right dose and combination for your individual situation.
What is trimethylglycine and does it interact with anything?
Trimethylglycine is an amino acid that supports homocysteine metabolism alongside the B vitamins in this product. We don't have interaction data on file for it, so we can't tell you whether it interacts with specific medications.
Does this product actually work for high homocysteine?
Vitamin B6 is likely effective for high homocysteine levels based on the data we hold. The other ingredients—folic acid, vitamin B12, trimethylglycine, grape skin, and red wine extract—may support that goal, but we don't have effectiveness ratings for trimethylglycine specifically, and the evidence for the plant extracts in this particular indication isn't established in our data.
What are the most common side effects?
At recommended doses, the B vitamins in this product are generally well tolerated. The most common side effects from vitamin B6 include headache, nausea, and heartburn. Folic acid and grape extracts may cause diarrhea or abdominal discomfort in some people. High doses of any of these can cause more serious effects—that's why you should stick to the recommended dose on the label.
Why are there warnings about seizure medications?
Vitamin B6 at high doses can make phenobarbital and phenytoin less effective by speeding up how your body breaks them down. Folic acid can directly interfere with how these medications control seizures. If you take either of those drugs, check with your doctor before adding this supplement.
Does this interact with blood thinners?
Yes—both grape skin extract and red wine extract have theoretical antiplatelet effects (meaning they may thin your blood slightly), so taking them with blood thinners or antiplatelet drugs like warfarin or aspirin could increase your bleeding risk. Ask your doctor or pharmacist before combining them.

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

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

Homocysteine Shield label
Go deeper

The Full Monographs Behind Homocysteine Shield’s Ingredients

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

Herb & supplement monograph

Vitamin B6

Interacts with 210 drugs

Vitamin B6 (pyridoxine) is an essential water-soluble vitamin that your body needs for metabolism, brain function, and making red blood cells. It is best known for helping with pregnancy-rel...

Read the full Vitamin B6 monograph → Herb & supplement monograph

Folic Acid

Interacts with 40 drugs

Folic acid is the man-made form of vitamin B9 and is one of the most well-studied supplements, especially for preventing serious birth defects when taken before and during early pregnancy. I...

Read the full Folic Acid monograph → Herb & supplement monograph

Vitamin B12

Interacts with 20 drugs

Vitamin B12 (cobalamin) is an essential nutrient your body needs to make red blood cells, keep nerves healthy, and support DNA. Supplements are very helpful for people who are deficient — su...

Read the full Vitamin B12 monograph → Herb & supplement monograph

Grape

Interacts with 910 drugs

Grapes and grape products like grape seed extract contain antioxidant compounds such as resveratrol and proanthocyanidins that may support heart and blood vessel health. While the food is he...

Read the full Grape monograph → Herb & supplement monograph

Resveratrol

Interacts with 822 drugs

Resveratrol is a plant compound found in red grapes, berries, and peanuts that is popular for heart health, anti-aging, and antioxidant support. While lab and animal studies are promising, s...

Read the full Resveratrol monograph →
Sources

Sources & How We Checked

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

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

The 176 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.

Vitamin B6 32 references
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Folic Acid 56 references
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Vitamin B12 30 references
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Grape 34 references
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  15. de Lange, D. W., Verhoef, S., Gorter, G., Kraaijenhagen, R. J., van de Wiel, A., and Akkerman, J. W. Polyphenolic grape extract inhibits platelet activation through PECAM-1: an explanation for the French paradox. Alcohol Clin.Exp.Res 2007;31(8):1308-1314 PubMed
  16. Etheridge, A. S., Black, S. R., Patel, P. R., So, J., and Mathews, J. M. An in vitro evaluation of cytochrome P450 inhibition and P-glycoprotein interaction with goldenseal, Ginkgo biloba, grape seed, milk thistle, and ginseng extracts and their constitu
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  22. Rabe, E., Stucker, M., Esperester, A., Schafer, E., and Ottillinger, B. Efficacy and tolerability of a red-vine-leaf extract in patients suffering from chronic venous insufficiency--results of a double-blind placebo-controlled study. Eur.J Vasc.Endovasc. PubMed
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  34. Moon SW, Shin YU, Cho H, Bae SH, Kim HK; and for the Mogen Study Group. Effect of grape seed proanthocyanidin extract on hard exudates in patients with non-proliferative diabetic retinopathy. Medicine (Baltimore) 2019;98(21):e15515. PubMed

See these in context on the Grape monograph →

Resveratrol 24 references
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See these in context on the Resveratrol monograph →

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

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