Drug & supplement interaction

Dulse + Penicillin G

Penicillin G brand name: Pfizerpen.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Dulse and Penicillin G in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Dulse and Penicillin G

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Penicillin G and Dulse in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Dulse safety at a glance

Dulse overall Use caution Generally safe as a food, but supplements may contain high iodine and potassium and should be used cautiously.
Pregnancy Use caution Food amounts are likely fine, but avoid concentrated supplements due to unpredictable iodine levels and limited safety data.
Breastfeeding Use caution Limited data; excess iodine can pass into breast milk, so avoid supplement doses and check with your doctor.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Penicillin G and Dulse? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Penicillin G

Interactions in our licensed database are recorded against drug classes, not just single drug names. Penicillin G is filed under 4 classifications — including antibiotic drugs, nephrotoxic drugs, seizure threshold lowering drugs. Dulse has documented interactions with 7 drug classes — the most serious being amiodarine (cordarone) (moderate), antithyroid drugs (moderate) and digoxin (lanoxin) (moderate) — and none of Penicillin G’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Dulse Does Interact With Other Medications

Dulse has 23 moderate, 62 minor known drug interactions in our database — Penicillin G isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Dulse

Covers the 2,830 medications we’ve checked against Dulse. Pick one to open its full report.

What to actually watch for

What Penicillin G’s Own FDA Label Lists

This is not an interaction — none of it involves Dulse. These are the most notable effects listed in the ADVERSE REACTIONS section of Penicillin G’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 10 of them are worth acting on rather than waiting out — marked below.

  • An electrolyte imbalance Worth acting on
  • High potassium Worth acting on
  • A heart attack Worth acting on
  • Blood clots Worth acting on
  • Wheezing Worth acting on
  • Seizures Worth acting on
  • Kidney problems Worth acting on
  • Anemia Worth acting on
  • A severe allergic reaction Worth acting on
  • Hives Worth acting on

Showing the 10 most notable of 30 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Penicillin G. Read the label on DailyMed › Dulse’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Dulse side to compare — that is a limit of the record, not a statement that Dulse has no side effects.

Everything else you take

See Every Supplement That Interacts With Penicillin G

This page covers Dulse only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Penicillin G page lists 56 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Siberian Cocklebur (major), Aristolochia (moderate) and Bacillus Coagulans (moderate).

By severity: 3 major · 42 moderate · 11 minor.

From our pharmacist’s overview on the Penicillin G page

“My concern with penicillin G (Pfizerpen), an injectable antibiotic reserved for serious infections such as syphilis and endocarditis, centers on a few supplements that deserve genuine respect. Siberian cocklebur and asarabacca can each harm the kidneys, extra strain nobody fighting a severe infection needs, while activated charcoal can…”

Reviewed by 2 · Jul 18, 2026

Open the Penicillin G interaction page

One more smart check

Taking Dulse as Part of a Dietary Supplement Product? Check It for Interactions

We hold 546 real supplement products containing Dulse, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Dulse. Even though Dulse itself has no known interaction with Penicillin G, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Dulse and Penicillin G Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Dulse
Top 25%

#325 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Penicillin G
Top half

#907 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Dulse reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Dulse and Penicillin G records this page draws on were last updated June 22, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Dulse

What is Dulse?

Dulse
  • Nutritional supplement (iodine, minerals)
  • Source of plant protein
  • General wellness
  • Anti-inflammatory support
  • Thyroid/iodine support

Dulse is a red seaweed eaten as a food in many coastal cultures and is a natural source of iodine, potassium, protein, and antioxidant compounds. As a food it is generally considered safe for most people, but concentrated supplements can deliver large amounts of iodine and potassium, so use caution. Talk to your pharmacist or doctor before using it medicinally, especially if you have thyroid or kidney problems.

Palmaria palmata · Palmariaceae · Whole edible thallus (the leafy seaweed fronds) · Dried flakes, whole dried leaf, powder, capsules, and as a food ingredient

An interaction check asks whether these two react with each other — it does not ask whether Dulse is a good idea for someone in your situation. Here is what our Dulse record says about it on its own.

Dulse: dosing

There is no established standardized medicinal dose for dulse. As a food it is eaten in small amounts as flakes, snacks, or a recipe ingredient.If you use a dulse supplement, follow the directions on the product label and do not exceed the recommended amount.

From our Dulse monograph — the full record covers uses, side effects and every documented interaction.

Read the full Dulse monograph & all interactions
Medication

About Penicillin G (Potassium, Sodium) Injection

What Is Penicillin G (Potassium, Sodium) Injection Used For?

Brand name: Pfizerpen

Penicillin G Potassium for Injection is used to treat serious infections caused by bacteria that are susceptible to penicillin. It covers a wide range of conditions, including bloodstream infections (septicemia), meningitis, pneumonia, endocarditis (heart valve infection), and pericarditis (infection around the heart).

It is also used for infections such as syphilis (including neurosyphilis and congenital syphilis), anthrax, diphtheria, botulism, tetanus, gas gangrene, disseminated gonococcal infections, listeria infections, and rat-bite fever, among others. Some uses are as adjunctive therapy — meaning penicillin G supports, but does not replace, other treatments like antitoxins.

See full Penicillin G (Potassium, Sodium) Injection drug information
Keep checking

Other Drugs & Dulse

Browse every other medication we’ve checked against Dulse — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
23Moderate
62Minor
2,744No known interaction
Moderate

23 interactions

Minor

62 interactions

Showing 60 of 62 minor interactions — see all 62 on the Dulse page.

No interaction 2,744 drugs checked — show the list
Evidence & sources

Dulse References

The 5 references that drive our Dulse monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Malta D, Arcand J, Ravindran A, Floras V, Allard JP, Newton GE. Adequate intake of potassium does not cause hyperkalemia in hypertensive individuals taking medications that antagonize the renin angiotensin aldosterone system. Am J Clin Nutr 2016 Oct;104(4 PubMed
  2. Allsopp P, Crowe W, Bahar B, et al. The effect of consuming Palmaria palmata-enriched bread on inflammatory markers, antioxidant status, lipid profile and thyroid function in a randomised placebo-controlled intervention trial in healthy adults. Eur J Nutr PubMed
  3. McGrath BM, Harmon JP, Bishop G. Palmaria palmata (Dulse) as an unusual maritime aetiology of hyperkalemia in a patient with chronic renal failure: a case report. J Med Case Rep. 2010;4:301. PubMed
  4. Furuta T, Miyabe Y, Yasui H, Kinoshita Y, Kishimura H. Angiotensin I converting enzyme inhibitory peptides derived from phycobiliproteins of dulse Palmaria palmata. Mar Drugs. 2016;14(2):32. PubMed
  5. Takase T, Nakamura A, Miyoshi H, et al. Effects of Palmaria palmata on lipid metabolism and glycemic control in participants with hypercholesterolemia in a randomized double-blind placebo-controlled trial. Phytother Res. 2020.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Dulse and Penicillin G Together: Common Questions

Is it safe to take Dulse with Penicillin G?
We do not list a known interaction between Dulse and Penicillin G. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
How was the Dulse and Penicillin G combination checked?
Interactions in our licensed database are recorded against drug classes. Penicillin G is filed under 4 classifications, and Dulse has documented interactions with 7 drug classes — none of Penicillin G's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Dulse interact with any other medications?
Yes. Dulse has 85 documented drug interactions in our database — Penicillin G is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Penicillin G interact with any supplements?
Yes. Penicillin G has documented interactions with 56 supplements in our database — Dulse is not one of them. The Penicillin G interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Penicillin G and Dulse?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.