Major interaction on record — check this product against your medications before combining. Based on 3 of 4 ingredients. Check your meds →
Dietary supplement

Blue-Green Algae 500 mg Ingredients & Drug Interactions

by NOW

Blue-Green Algae 500 mg label
See full label image
Capsule Category: Botanical
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Blue-Green Algae 500 mg 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-Green Algae 500 mg is a dietary supplement by NOW with 4 active ingredients. Its ingredients are commonly taken for iron-deficiency anemia, low iron stores during pregnancy, fatigue from iron deficiency.Based on those ingredients, 696 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Vitamin A, Blue Green Algae, Iron. 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-Green Algae 500 mg by NOW

Ask about any prescription or over-the-counter medication and we check it for interactions with Blue-Green Algae 500 mg by NOW — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Blue-Green Algae 500 mg by NOW

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 16, 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 3 of its 3 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Blue-Green Algae 500 mg by NOW contains three active ingredients: iron, vitamin A, and blue-green algae. Iron supports red blood cell function and oxygen transport.

Vitamin A is a fat-soluble vitamin important for vision, skin, and immune health. Blue-green algae are a microorganism source of nutrients and compounds that may support various body functions.

The product also contains cellulose and magnesium stearate as inactive ingredients (binders and flow agents in the capsule).

Does it work?

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

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

Strong

Strong clinical evidence supports its ingredients for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredients' overall clinical evidence instead.
  • On file: Anemia of chronic disease — rated "Effective" (Iron) (Natural Medicines).
  • On file: Vitamin A deficiency — rated "Effective" (Vitamin A) (Natural Medicines).
  • On file: Iron deficiency anemia — rated "Effective" (Iron) (Natural Medicines).
  • On file: Pregnancy-related iron deficiency — rated "Effective" (Iron) (Natural Medicines).
  • On file: Aging skin — rated "Possibly Effective" (Vitamin A) (Natural Medicines).

Iron is effective for treating iron deficiency anemia and anemia of chronic disease, and is commonly used in pregnancy when prescribed by a healthcare provider. Vitamin A is effective for vitamin A deficiency and is possibly effective for oral leukoplakia, aging skin, measles, ulcerative colitis, and bronchopulmonary dysplasia.

For blue-green algae, evidence suggests it may be possibly effective for high blood pressure, but the evidence isn't established for acne, hay fever, iron deficiency anemia, or arsenic poisoning according to the data we hold.

The evidence, ingredient by ingredient Iron Vitamin A Blue-green Algae

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 3 of the 3 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 3 of 3.
  • General safety write-ups exist for 3 of 3.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Iron is generally well tolerated at recommended doses, though it can cause gastrointestinal side effects like abdominal pain, constipation, diarrhea, nausea, and vomiting. Vitamin A is generally safe at recommended amounts, but high doses can build up in your body and cause toxicity — in very high doses it can affect the liver, cause headache, and in rare cases more serious effects.

Iron is often recommended in pregnancy but the dose should be guided by your prenatal care provider; vitamin A in recommended amounts is needed in pregnancy but high doses (especially as retinol) can cause birth defects and should be avoided. For blue-green algae, quality varies and some products can be contaminated with toxins or heavy metals — contamination is a concern, and safety data is limited.

Side effects, ingredient by ingredient Iron Vitamin A Blue-green Algae

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?
  • 3 of the 3 matched ingredients can interact with medications — Iron, Blue-green Algae, Vitamin A.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; diabetes medications; Parkinson's medications.
  • For scale: 697 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 any blood thinner or antiplatelet medications you take — iron can interact with blood thinners like warfarin, and blue-green algae theoretically increase bleeding risk. Also verify any tetracycline or quinolone antibiotics, thyroid medication (levothyroxine), bisphosphonates, methyldopa for blood pressure, retinoid medications, immunosuppressants, or diabetes medications you're on.

The iron and vitamin A in this product can reduce how well many of these work or increase side effects if taken at the same time.

Check your own medication Run your meds through the checker above

The bottom line

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

This product combines three active ingredients that may support specific needs — iron for anemia, vitamin A for deficiency and eye health, and blue-green algae for potential nutrient support. However, iron and vitamin A both have significant interactions with common medications, and blue-green algae products carry a contamination risk.

If you take any prescription medications, especially blood thinners, antibiotics, thyroid medication, or retinoids, check them against the medication tool on this page. Talk with your doctor or pharmacist before starting, especially if you're pregnant, breastfeeding, or taking medications.

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

Assessment coverage: 3 of 3 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Oct 1, 2012.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Blue-Green Algae 500 mg, straight from the product label.

Brand NOW
Barcode (UPC) 733739026231
Net contents 90 Veg Capsule(s)
Market status On market
Date entered into DSLD Oct 1, 2012
DSLD ID 13781
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Blue-Green Algae 500 mg by NOW, 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 Vegetarian Capsule(s)
Maximum serving Sizes:
4 Vegetarian Capsule(s)
Servings per container
22
UPC/BARCODE
733739026231
IngredientAmount% DV
Calories5 {Calories}--
Protein1 g2%
Iron0.7 mg4%
Vitamin A560 IU11%
Blue Green Algae2 g--

Other ingredients: Cellulose, Magnesium Stearate

Tap any ingredient to jump to its full detail below.

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

SUGGESTED USAGE: As a dietary supplement, take 2 to 4 capsules daily. Start with a smaller amount and gradually increase dosage over several weeks. Consider taking these other NOW(R) products: Energy, Detox Support(TM) and Triphala.

Brand IP Statement(s)

NOW(R) Blue-Green Algae delivers the natural nutrient profile found in Genuine Whole Foods.

General Statements

Blue-Green Algae is a unique superfood harvested from the pristine Upper Klamath Lake in the Oregon Cascades. This nutrient-dense, freeze-dried, whole food concentrate has naturally occurring minerals, vitamins, protein and chlorophyll.

CAPSULE SIZE Made in the USA

Genuine Whole Food

GREEN SUPERFOOD

Wildcrafted from Klamath Lake

For more product information visit www.nowfoods.com/2623

Natural color variations may occur in this product.

Please Recycle.

Precautions

Caution: For adults only.

Consult physician if pregnant/nursing, taking medication, or have a medical condition.

Keep out of reach of children.

Do Not Eat Freshness Packet. Keep in Bottle.

FDA Statement of Identity

A Dietary Supplement

Formulation

Vegetarian/Vegan

Seals/Symbols

GMP QUALITY ASSURED

Storage

Store in a cool, dry place after opening.

General

CODE 2623 V3

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

See for yourself

Blue-Green Algae 500 mg by NOW label

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

Blue-Green Algae 500 mg 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-Green Algae 500 mg by NOW

These are the 4 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Vegetarian Capsule(s) Dosage formCapsule Servings per container22 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.

Protein

1 g per serving

Iron

Interacts with
80 drugs
0.7 mg per serving

Iron is an essential mineral your body needs to make hemoglobin and carry oxygen in the blood. Supplements are mainly useful for treating or preventin...

Iron monograph & interactions

Vitamin A

Interacts with
387 drugs
560 IU per serving Form: Beta-Carotene

Vitamin A is an essential nutrient important for vision, skin, immune function, and growth. Most people get enough from a balanced diet, and supplemen...

Vitamin A monograph & interactions

Blue Green Algae

Interacts with
327 drugs
2 g per serving

Blue-green algae are nutrient-rich aquatic microorganisms (such as spirulina and Klamath Lake algae) taken as a supplement for energy, nutrition, and...

Blue Green Algae monograph & interactions

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

Interaction report

Blue-Green Algae 500 mg by NOW Drug Interactions

Want to check YOUR meds against Blue-Green Algae 500 mg?

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
696Drugs
9 Major 686 Moderate 1 Minor

Ingredients driving the most interactions

Vitamin A 387
Blue Green Algae 327
Iron 80

Individual Drug Interactions

The ingredients in Blue-Green Algae 500 mg interact with 696 drugs. Click any drug to see the details.

3 of the 4 ingredients in Blue-Green Algae 500 mg interact with drugs. Each result below shows which ingredient is responsible. Vitamin A Blue Green Algae Iron

Each ingredient & the kinds of drugs it affects

For each ingredient in Blue-Green Algae 500 mg 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.

Vitamin A4 drug types · 387 drugs

Retinoids

Concomitant use of retinoids with vitamin A supplements might produce supratherapeutic vitamin A levels.
Retinoids, which are vitamin A derivatives, could have additive toxic effects when taken with vitamin A supplements.

Likelihood Probable Evidence D
Hepatotoxic Drugs

Theoretically, taking high doses of vitamin A in combination with other potentially hepatotoxic drugs might increase the risk of liver disease.
The tolerable upper intake level (UL) is the highest level of intake that is likely to pose no risk of adverse effects. Doses of vitamin A above the UL can cause hepatotoxicity, ranging from elevated liver enzymes to liver failure.

Likelihood Possible Evidence C
Tetracycline Antibiotics

Theoretically, taking tetracycline antibiotics with high doses of vitamin A can increase the risk of pseudotumor cerebri.
Benign intracranial hypertension (pseudotumor cerebri) can occur with tetracyclines and with acute or chronic vitamin A toxicity. Case reports suggest that taking tetracyclines and vitamin A concurrently can increase the risk of this condition. Avoid high doses of vitamin A in people taking tetracyclines chronically.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, high doses of vitamin A could increase the risk of bleeding with warfarin.
Vitamin A toxicity is associated with hemorrhage and hypoprothrombinemia, possibly due to vitamin K antagonism. Advise patients taking warfarin to avoid doses of vitamin A above the tolerable upper intake level of 10,000 IU/day for adults.

Likelihood Possible Evidence D
Vitamin A full monograph & interactions

Blue Green Algae3 drug types · 327 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, spirulina blue-green algae might increase the risk of bleeding if used with other anticoagulant or antiplatelet drugs. However, this is unlikely.
Spirulina blue-green algae have shown antiplatelet and anticoagulant effects in vitro. However, one preliminary study in 24 patients receiving spirulina blue-green algae 2.3 grams daily for 2 weeks showed no effect on platelet activation or measures of clotting time.

Likelihood Unlikely Evidence D
Antidiabetes Drugs

Theoretically, taking blue-green algae with antidiabetes drugs might increase the risk of hypoglycemia.
Human research shows that spirulina blue-green algae can have hypoglycemic effects in patients with diabetes, at least some of whom were using antidiabetes drugs. However, blue-green algae does not seem to improve glycated hemoglobin (HbA1c) levels in patients with diabetes. A meta-analysis of animal studies also suggests that spirulina blue-green algae have hypoglycemic effects.

Likelihood Possible Evidence B
Immunosuppressants

Theoretically, concurrent use of blue-green algae might interfere with immunosuppressive therapy.
Blue-green algae have been shown to stimulate the immune system.

Likelihood Possible Evidence D
Blue Green Algae full monograph & interactions

Iron13 drug types · 80 drugs

Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)

Iron 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 iron 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, iron containing products.

Likelihood Probable Evidence D
Bisphosphonates

Iron reduces the absorption of bisphosphonates.
Advise patients that doses of bisphosphonates should be separated by at least two hours from doses of all other medications, including supplements such as iron. Divalent cations, including iron, can decrease absorption of bisphosphonates by forming insoluble complexes in the gastrointestinal tract.

Likelihood Probable Evidence D
Denosumab (Prolia, Others)

Administration of intravenous iron within one month of denosumab administration might increase the risk of severe hypophosphatemia and hypocalcemia.
A case of severe hypocalcemia (albumin corrected calcium 6.88 mg/dL, ionized calcium 3.68 mg/dL) and hypophosphatemia (<0.5 mg/dL) with respiratory acidosis, QT interval prolongation, and nonsustained ventricular tachycardia was reported in a 76-year-old male who had received an iron polymaltose infusion within 2 weeks of a subcutaneous injection of denosumab. Serum parathyroid hormone was also elevated (348 pg/mL). Subsequent iron infusions with iron polymaltose and ferric carboxymaltose were followed by transient hypophosphatemia, but without hypocalcemia. Additionally, a literature review describes 6 additional cases of hypophosphatemia and hypocalcemia in patients 52-92 years of age who had been administered intravenous iron as either ferric carboxymaltose or iron polymaltose and subcutaneous denosumab within 1-4 weeks of each other.

Likelihood Possible Evidence D
Dolutegravir (Tivicay)

Iron might decrease dolutegravir levels by reducing its absorption.
Advise patients to take dolutegravir at least 2 hours before or 6 hours after taking iron. Pharmacokinetic research shows that iron can decrease the absorption of dolutegravir from the gastrointestinal tract through chelation. When taken under fasting conditions, a single dose of ferrous fumarate 324 mg orally along with dolutegravir 50 mg reduces overall exposure to dolutegravir by 54%.

Likelihood Probable Evidence B
Integrase Inhibitors

Theoretically, taking iron along with integrase inhibitors might decrease the levels and clinical effects of these drugs.
Iron is a divalent cation. There is concern that iron may decrease the absorption of integrase inhibitors from the gastrointestinal tract through chelation. One pharmacokinetic study shows that iron can decrease blood levels of the specific integrase inhibitor dolutegravir through chelation. Also, other pharmacokinetic research shows that other divalent cations such as calcium can decrease the absorption and levels of some integrase inhibitors through chelation.

Likelihood Possible Evidence D
Levodopa

Iron might decrease levodopa levels by reducing its absorption.
Advise patients to separate doses of levodopa and iron as much as possible. There is some evidence in healthy people that iron forms chelates with levodopa, reducing the amount of levodopa absorbed by around 50%. The clinical significance of this hasn't been determined.

Likelihood Probable Evidence B
Levothyroxine (Synthroid, Others)

Iron might decrease levothyroxine levels by reducing its absorption.
Advise patients to separate levothyroxine and iron doses by at least 2 hours. Iron can decrease the absorption and efficacy of levothyroxine by forming insoluble complexes in the gastrointestinal tract.

Likelihood Probable Evidence B
Methyldopa (Aldomet)

Iron might decrease methyldopa levels by reducing its absorption.
Advise patients to separate methyldopa and iron doses by at least 2 hours. Iron can decrease the absorption of methyldopa from the gastrointestinal tract through chelation, resulting in increases in blood pressure.

Likelihood Probable Evidence B
Mycophenolate Mofetil (Cellcept)

Theoretically, iron might decrease mycophenolate mofetil levels by reducing its absorption.
Advise patients to take iron 4-6 hours before, or 2 hours after, mycophenolate mofetil. It has been suggested that a decrease of absorption is possible, probably by forming nonabsorbable chelates. However, mycophenolate pharmacokinetics are not affected by iron supplementation in available clinical research.

Likelihood Unlikely Evidence D
Penicillamine (Cuprimine, Depen)

Iron might decrease penicillamine levels by reducing its absorption.
Advise patients to separate penicillamine and iron doses by at least 2 hours. Oral iron supplements can reduce absorption of penicillamine by 30% to 70%, probably due to chelate formation. In people with Wilson's disease, this interaction has led to reduced efficacy of penicillamine.

Likelihood Probable Evidence D
Quinolone Antibiotics

Iron might decrease levels of quinolone antibiotics by reducing their absorption.
Advise patients to separate quinolone antibiotics and iron doses by at least 2 hours. Iron decreases the absorption of quinolones due to formation of insoluble complexes in the gastrointestinal tract.

Likelihood Probable Evidence D
Tetracycline Antibiotics

Iron might decrease levels of tetracycline antibiotics by reducing their absorption.
Advise patients to take iron at least 2 hours before or 4 hours after tetracycline antibiotics. Concomitant use can decrease absorption of tetracycline antibiotics from the gastrointestinal tract by 50% to 90%.

Likelihood Probable Evidence D
Chloramphenicol

Theoretically, taking chloramphenicol with iron might reduce the response to iron therapy in iron deficiency anemia.
Chloramphenicol interferes with erythrocyte maturation. However, since chloramphenicol isn't usually taken for prolonged periods, this isn't likely to be clinically significant.

Likelihood Unlikely Evidence D
Iron full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Blue-Green Algae 500 mg, from the product label.

NOW

See all NOW products
Name
NOW FOODS
Street Address
395 S. Glen Ellyn Rd.
City
Bloomingdale
State
IL
ZipCode
60108
Pharmacist Counseling Corner

Blue-Green Algae 500 mg by NOW: Common Questions

Does Blue-Green Algae 500 mg by NOW interact with any medications?
Yes. Based on its ingredients, Blue-Green Algae 500 mg has a known interaction with 696 medications, including 9 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Blue-Green Algae 500 mg contains 4 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?
Iron is often used in pregnancy but the dose should be guided by your prenatal care provider. Vitamin A in recommended amounts is needed, but high doses — especially as retinol — can cause birth defects and should be avoided. Because this product contains both and safety information for blue-green algae in pregnancy isn't on file, check with your doctor or pharmacist before taking it.
Can I take this while breastfeeding?
Iron is generally considered acceptable while breastfeeding at appropriate doses. Vitamin A at normal dietary and recommended supplement amounts is appropriate while breastfeeding. We don't have safety information on blue-green algae for breastfeeding, so talk with your provider before using this product.
What side effects might I experience?
Iron can cause abdominal pain, constipation, diarrhea, nausea, and vomiting. Blue-green algae may cause abdominal cramps, bloating, diarrhea, dizziness, fatigue, headache, nausea, and vomiting. Very high doses of vitamin A can cause serious effects, but at recommended levels the risk is low. Allergic reactions to blue-green algae are rare but possible.
Does blue-green algae actually help with anything?
According to our data, blue-green algae may possibly help with high blood pressure, but the evidence isn't established for conditions like acne, hay fever, or anemia. The supplement does contain nutrients, but quality and contamination vary between products.
Why does the label list so many medication interactions?
Iron in this product reduces how the stomach absorbs several medications — antibiotics, thyroid drugs, bisphosphonates, and others — by binding to them chemically. Vitamin A at high doses interacts with retinoids and blood thinners. Most of these can be managed by separating doses by a few hours, which is why checking your exact medications is important.
Is there a contamination concern with this product?
Yes — blue-green algae products can contain toxins or heavy metals depending on their source and how they're processed. Quality varies, so if you're considering this product, talk with your pharmacist about the specific brand and whether it's been tested for purity.

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.

Blue-Green Algae 500 mg label
Go deeper

The Full Monographs Behind Blue-Green Algae 500 mg’s Ingredients

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

Herb & supplement monograph

Iron

Interacts with 80 drugs

Iron is an essential mineral your body needs to make hemoglobin and carry oxygen in the blood. Supplements are mainly useful for treating or preventing iron deficiency and iron-deficiency an...

Read the full Iron monograph → Herb & supplement monograph

Vitamin A

Interacts with 387 drugs

Vitamin A is an essential nutrient important for vision, skin, immune function, and growth. Most people get enough from a balanced diet, and supplements are mainly useful for correcting a tr...

Read the full Vitamin A monograph → Herb & supplement monograph

Blue-green Algae

Interacts with 327 drugs

Blue-green algae are nutrient-rich aquatic microorganisms (such as spirulina and Klamath Lake algae) taken as a supplement for energy, nutrition, and general wellness. Evidence for most heal...

Read the full Blue-green Algae monograph →
Sources

Sources & How We Checked

Blue-Green Algae 500 mg'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 125 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.

Iron 72 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Bruner AB, Joffe A, Duggan AK, et al. Randomized study of cognitive effects of iron supplementation in non- anaemic iron-deficient adolescent girls. Lancet 1996;348:992-6.
  3. Ullen H, Augustsson K, Gustavsson C, Steineck G. Supplementary iron intake and risk of cancer: reversed causality? Cancer Lett 1997;114:215-6.
  4. Reunanen A, Takkunen H, Knekt P, et al. Body iron stores, dietary iron intake and coronary heart disease mortality. J Intern Med 1995;238:223-30. PubMed
  5. Lund EK, Wharf SG, Fairweather-Tait SJ, Johnson IT. Oral ferrous sulfate supplements increase the free radical-generating capacity of feces from healthy volunteers. Am J Clin Nutr 1999;69:250-5.
  6. Rehman A, Collis CS, Yang M, et al. The effects of iron and vitamin C co-supplementation on oxidative damage to DNA in healthy volunteers. Biochem Biophys Res Comm 1998;246:293-8. PubMed
  7. Klipstein-Grobusch K, Grobbee DE, den Breeijen JH, et al. Dietary iron and risk of myocardial infarction in the Rotterdam Study. Am J Epidemiol 1999;149:421-8. PubMed
  8. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  9. Tatro DS, ed. Drug Interactions Facts. Facts and Comparisons Inc., St. Louis, MO. 1999.
  10. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
  11. Campbell N, Paddock V, Sundaram R. Alteration of methyldopa absorption, metabolism, and blood pressure control by ferrous sulfate and ferrous gluconate. Clin Pharmacol Ther 1988;43:381-6..
  12. Schumann K, Borch-Iohnsen B, Hentze MW, Marx JJ. Tolerable upper intakes for dietary iron set by the US Food and Nutrition Board (commentary). Am J Clin Nutr 2002;76:499-500. PubMed
  13. Tuomainen TP, Punnonen K, Nyyssonen K, Salonen JT. Association between body iron stores and the risk of acute myocardial infarction in men. Circulation 1998;97:1461-6.. PubMed
  14. Salonen JT, Nyyssonen K, Korpela H, et al. High stored iron levels are associated with excess risk of myocardial infarction in Eastern Finnish men. Circulation 1992;86:803-11.. PubMed
  15. Campbell NRC, Hasinoff B. Ferrous sulfate reduces levodopa bioavailability: Chelation as a possible mechanism. Clin Pharmacol Ther 1989;45:220-5.. PubMed
  16. Campbell NRC, Hasinoff BB, Stalts H, et al. Ferrous sulfate reduces thyroxine efficacy in patients with hypothyroidism. Ann Int Med 1992;117:1010-3.. PubMed
  17. Kiechl S, Willeit J, Egger G, et al. Body iron stores and the risk of carotid atherosclerosis: prospective results from the Bruneck study. Circulation 1997;96:3300-07. PubMed
  18. Comparison of oral iron supplements. Pharmacist's Letter / Prescriber's Letter 2008;24(8):240811.
  19. Tran T., Wax J. R., Philput C., Steinfeld J. D., Ingardia C. J. Intentional iron overdose in pregnancy--management and outcome. J Emerg Med 2000;18(2):225-228. PubMed
  20. Toblli J. E., Brignoli, R. Iron(III)-hydroxide polymaltose complex in iron deficiency anemia / review and meta-analysis. Arzneimittelforschung 2007;57(6A):431-438. PubMed
  21. Köpcke W., Sauerland M. C. Meta-analysis of efficacy and tolerability data on iron proteinsuccinylate in patients with iron deficiency anemia of different severity. Arzneimittelforschung 1995;45(11):1211-1216.
  22. Campbell N. R., Campbell R. R., Hasinoff B. B. Ferrous sulfate reduces methyldopa absorption: methyldopa: iron complex formation as a likely mechanism. Clin Invest Med 1990;13(6):329-332.
  23. Morii M., Ueno K., Ogawa A., Kato R., Yoshimura H., Wada K., Hashimoto H., Takada M., Tanaka K., Nakatani T., Shibakawa M. Impairment of mycophenolate mofetil absorption by iron ion. Clin Pharmacol Ther 2000;68(6):613-616. PubMed
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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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