Major interaction on record — check this product against your medications before combining. Check your meds →
Dietary supplement

Blue Flag Ingredients & Drug Interactions

by Herbal Terra

Blue Flag label
See full label image
Liquid Category: Botanical
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

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

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

The interaction bottom line Most serious interaction: Major

Blue Flag is a dietary supplement by Herbal Terra with 1 active ingredient. Its ingredients are commonly taken for skin conditions like acne and eczema, constipation and digestive complaints, liver and gallbladder support (traditional).Based on those ingredients, 78 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Blue Flag Root Extract, Dry. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Blue Flag by Herbal Terra

Ask about any prescription or over-the-counter medication and we check it for interactions with Blue Flag by Herbal Terra — 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 Blue Flag by Herbal Terra

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 11, 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 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: blue flag root extract (dry form). Blue flag is a botanical traditionally used for its laxative properties.

The liquid is prepared with alcohol, water, and glycerin as inactive ingredients to deliver the extract.

Does it work?

Couldn't assess
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
Not assessable

This is a single-ingredient Blue Flag product and its label doesn't state a use — see Blue Flag's own graded uses on its monograph.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

We don't hold effectiveness ratings for blue flag root extract in our data, so we cannot tell you how well this ingredient is proven to work for any particular condition. If you're considering this product for a specific health goal, ask us or your doctor what the evidence shows.

The evidence, ingredient by ingredient Blue Flag

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 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Blue flag root extract can cause nausea, vomiting, and throat irritation—especially the fresh root. The volatile oil it contains irritates mucous membranes and may cause headache, eye inflammation, and tearing.

The safety data advises against use during pregnancy because of potential toxicity and lack of safety information. It is likely unsafe while breastfeeding, so avoid it if you're nursing.

Side effects, ingredient by ingredient Blue Flag

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

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

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Blue Flag.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; heart-rhythm medications.
  • For scale: 78 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 this product, double-check it with your pharmacist if you take digoxin (a heart medication)—that's a major interaction. Also check if you're on any diuretics (water pills) or warfarin (a blood thinner), both moderate concerns.

These account for the serious risks with this product.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Major medication interactions have been identified, and safety information is well characterized.

Blue flag is a traditional laxative, but it carries real risks with heart medications, water pills, and blood thinners. If you take digoxin, diuretics, or warfarin, check with your pharmacist before starting.

Pregnant or breastfeeding? Skip this one.

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

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Nov 22, 2024.

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 Blue Flag, straight from the product label.

Brand Herbal Terra
Barcode (UPC) 7386004857974
Net contents 2 Fluid Ounce(s); 60 mL
Market status On market
Date entered into DSLD Nov 22, 2024
DSLD ID 324835
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten 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 Blue Flag by Herbal Terra, 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 mL
Maximum serving Sizes:
1 mL
Servings per container
60
UPC/BARCODE
7386004857974
IngredientAmount% DV
Blue Flag Root Extract, Dry983 mg--

Other ingredients: Alcohol, Water, Glycerin

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions

Shake well before use. Adults take up to 30 drops (1 mL, one full squeeze of the dropper bulb) in 3-4 fl. oz. of juice or water up to 4 times a day.

Precautions

We recommend to seek expert medical advice before taking. May have contraindications and cause adverse reaction.

Consult a physician before giving to children under 18, before using during pregnancy, if nursing, or if you are on any medications.

Consult a physician before giving to children under 18, before using during pregnancy, if nursing, or if you are on any medications. Keep out of the reach of children!

Do not use if you are allergic to any ingredients.

Storage

Store in a cool, dry, dark place.

FDA Disclaimer Statement

This product has not been evaluated by the FDA and is not intended to diagnose, treat, cure or prevent any disease.

Formulation

cGMP Made in compliance with cGMP 21 CFR 111 in an FDA registered and inspected facility.

Sugar free

Expertly extracted 100% natural Premium product

Organic alcohol

No artificial ingredients, color additives, fillers or binders.

Natural Gluten free

Formula

Iris versicolor

Organic alcohol

FDA Statement of Identity

Herbal Supplement

Seals/Symbols

Made in USA

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

See for yourself

Blue Flag by Herbal Terra label

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

Blue Flag 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 Blue Flag by Herbal Terra

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 mL Dosage formLiquid Servings per container60 Amounts shown are per serving.

Blue Flag Root Extract, Dry

Interacts with
78 drugs
983 mg per serving

Blue Flag is a flowering plant whose root has been used in traditional and herbal medicine for skin and digestive complaints, but there is very little...

Blue Flag Root Extract, Dry monograph & interactions

Other (inactive) ingredients: Alcohol, Water, Glycerin. These complete the product’s ingredient list but are not active constituents.

Interaction report

Blue Flag by Herbal Terra Drug Interactions

Want to check YOUR meds against Blue Flag?

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
78Drugs
1 Major 77 Moderate

Ingredients driving the most interactions

Blue Flag Root Extract, Dry 78

Individual Drug Interactions

The ingredients in Blue Flag interact with 78 drugs. Click any drug to see the details.

1 of the 1 ingredient in Blue Flag interact with drugs. Each result below shows which ingredient is responsible. Blue Flag Root Extract, Dry

Each ingredient & the kinds of drugs it affects

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

Blue Flag Root Extract, Dry3 drug types · 78 drugs

Digoxin (Lanoxin)

Theoretically, overuse or abuse of this product increases the risk of adverse effects from cardiac glycoside drugs.

Likelihood Probable Evidence D
Diuretic Drugs

Overuse of blue flag might compound diuretic-induced potassium loss. There is some concern that people taking blue flag along with potassium depleting diuretics might have an increased risk for hypokalemia. Initiation of potassium supplementation or an increase in potassium supplement dose may be necessary for some patients. Some diuretics that can deplete potassium include chlorothiazide (Diuril), chlorthalidone (Thalitone), furosemide (Lasix), hydrochlorothiazide (HCTZ, Hydrodiuril, Microzide), and others.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Blue flag has stimulant laxative effects. In some people blue flag can cause diarrhea. Diarrhea can increase the effects of warfarin, increase international normalized ratio (INR), and increase the risk of bleeding. Advise patients who take warfarin not to take excessive amounts of blue flag.

Likelihood Possible Evidence D
Blue Flag Root Extract, Dry full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Blue Flag, from the product label.

Herbal Terra

See all Herbal Terra products
Name
Herbal Terra LLC
Phone Number
+18083857868
Web Address
herbalterra.com
Pharmacist Counseling Corner

Blue Flag by Herbal Terra: Common Questions

Does Blue Flag by Herbal Terra interact with any medications?
Yes. Based on its ingredients, Blue Flag has a known interaction with 78 medications, including 1 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Blue Flag contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism 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 Blue Flag if I'm pregnant?
No. The safety data advises against it because of potential toxicity and lack of safety information. Talk with your doctor before considering any supplement during pregnancy.
Is it safe to breastfeed while taking this?
No. Blue flag is likely unsafe while breastfeeding due to lack of safety information. If you're nursing, avoid this product.
What side effects might I notice?
Blue flag can cause nausea, vomiting, and throat irritation. The volatile oil in it may also cause headache, eye inflammation, and tearing. These effects are more likely if you use it heavily.
Why does blue flag interact with water pills?
Blue flag is a laxative, and overuse can cause diarrhea. That increases fluid loss on top of what your water pill already removes, which can lower your potassium to unsafe levels. Your doctor or pharmacist may need to adjust your potassium supplementation.

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

Not sure if Blue Flag is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.

Blue Flag label
Go deeper

The Full Monographs Behind Blue Flag’s Ingredients

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

Herb & supplement monograph

Blue Flag

Interacts with 78 drugs

Blue Flag is a flowering plant whose root has been used in traditional and herbal medicine for skin and digestive complaints, but there is very little modern scientific evidence to support t...

Read the full Blue Flag monograph →
Sources

Sources & How We Checked

Blue Flag'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 3 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.

Blue Flag 3 references
  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  3. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

See these in context on the Blue Flag 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

Keep exploring
Supplement interaction checker › Check any supplement or product against your medications Drug–drug interactions › Check two or more of your medications against each other Browse medications A–Z › Every drug we've checked against herbs & supplements NDC & pricing lookup › Find a drug’s NDCs, packaging and costs Ask a pharmacist › Free, personal answer from our licensed team