Drug & supplement interaction

Laminaria + Olaparib

Olaparib brand name: Lynparza.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Laminaria and Olaparib 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Laminaria and Olaparib

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 Olaparib and Laminaria 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.

Laminaria safety at a glance

Laminaria overall Use caution Generally safe as food, but supplements can deliver very high, variable amounts of iodine that may affect the thyroid.
Pregnancy Possibly Unsafe When used intravaginally for cervical ripening; there is an increased risk of parental and neonatal infection. Read the full pregnancy detail
Breastfeeding Likely Unsafe When used orally because of potential toxicity. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Olaparib and Laminaria? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Olaparib

Interactions in our licensed database are recorded against drug classes, not just single drug names. Olaparib is filed under 2 classifications — cytochrome p450 3a4 (cyp3a4) substrates, oral drugs. Laminaria has documented interactions with 6 drug classes — the most serious being ace inhibitors (aceis) (moderate), amiodarone (cordarone) (moderate) and antithyroid drugs (moderate) — and none of Olaparib’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

Laminaria Does Interact With Other Medications

Laminaria has 69 moderate known drug interactions in our database — Olaparib isn’t one of them. If you take anything else, check it against the full list below.

Moderate 69 No known interaction 2,761 (incl. Olaparib)
Taking anything else?

Check Another of Your Medications Against Laminaria

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

What to actually watch for

No Interaction Found — But Data Suggests Laminaria and Olaparib May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • A higher chance of infection Worth acting on Additional detail

    Laminaria

    “Intravaginally, laminaria used for cervical ripening can cause pelvic cramps and cervical bleeding. Uterine contractions associated with laminaria use have been implicated in fetal hypoxia and subsequent intrauterine death (6). Use of endocervical laminaria tents has been associated with possible rupture of the cervical wall and subsequent neonatal and parental infection (6,8945).”

    Laminaria · Natural Medicines adverse-effect record, reported in bleeding.

    2 sources cited
    1. 8945. Kazzi GM, Bottoms SF, Rosen MG. Efficacy and safety of Laminaria digitata for preinduction ripening of the cervix. Obstet Gynecol 1982;60:440-3..
    2. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.

    Olaparib

    Listed in the ADVERSE REACTIONS section of the FDA label for Olaparib. Read the label on DailyMed ›

  • Tiredness / Vomiting / Diarrhea / Headache reported in 8.5% of FDA reports for Olaparib Additional detail

    Laminaria

    “Laminaria concentrates arsenic from the ocean. In one case, use of an oral laminaria supplement for several months resulted in symptoms of arsenic poisoning including headache, weakness, fatigue, worsening memory loss, rash, nail damage, diarrhea, and vomiting. Urinary arsenic levels were elevated.”

    Laminaria · Natural Medicines adverse-effect record, reported in arsenic poisoning.

    3 sources cited
    1. 15588. Amster E, Tiwary A, Schenker MB. Case report: potential arsenic toxicosis secondary to herbal kelp supplement. Environ Health Perspect 2007;115:606-8. PubMed
    2. 645. Pye KG, Kelsey SM, House IM, et al. Severe dyserythropoeisis and autoimmune thrombocytopenia associated with ingestion of kelp supplement. Lancet 1992;339:1540.
    3. 10275. Norman JA, Pickford CJ, Sanders TW, Waller M. Human intake of arsenic and iodine from seaweed-based food supplements and health foods available in the UK. Food Addit Contam 1988;5:103-9.. PubMed

    Olaparib

    Listed in the ADVERSE REACTIONS section of the FDA label for Olaparib, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Laminaria but not commonly for Olaparib: a change in thyroid levels, memory problems, a severe allergic reaction and bleeding or bruising.

Effects for Olaparib come from the ADVERSE REACTIONS section of its FDA label; effects for Laminaria come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 20,798 voluntary FDA FAERS reports for Olaparib that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Laminaria in Pregnancy & Breastfeeding

Pregnancy Possibly Unsafe

When used intravaginally for cervical ripening; there is an increased risk of parental and neonatal infection.

Pregnancy Likely Unsafe

When used intravaginally to induce labor; use has been associated with endometriosis, neonatal sepsis, fetal hypoxia, and intrauterine death.

Pregnancy Unsafe

When used orally due to potential hormonal effects; avoid using.

Lactation Likely Unsafe

When used orally because of potential toxicity.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Overlapping uses

What Olaparib Is Prescribed For, and What Laminaria Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Olaparib is a prescription medicine with approved uses on its FDA label. Laminaria is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Olaparib is prescribed for: Lynparza (olaparib) is used to treat adults with certain ovarian, fallopian tube, or primary peritoneal cancers that carry BRCA or other DNA-repair gene mutations — both as a maintenance therapy after platinum-based chemotherapy (including in combination with bevacizumab for some patients) and for recurrent disease. It is also approved for HER2-negative breast cancer with a germline BRCA mutation, both in early high-risk disease (adjuvant setting) and in metastatic disease. Lynparza is additionally used as maintenance therapy for adults with germline BRCA-mutated metastatic pancreatic adenocarcinoma whose disease has not progressed on first-line platinum-based chemotherapy, and for adults with certain gene-mutated metastatic castration-resistant prostate cancer — either alone (after prior enzalutamide or abiraterone) or in combination with abiraterone and prednisone or prednisolone. All uses require testing for specific genetic mutations using an FDA-approved companion diagnostic before starting treatment.

Laminaria has been studied for:

  • Cancer studied, not established Laminaria has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Laminaria for cancer

    Although there has been interest in using oral laminaria for cancer prevention, there is insufficient reliable information about the clinical effects of laminaria for this purpose.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Olaparib on your own; if you are taking Laminaria for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

Everything else you take

See Every Supplement That Interacts With Olaparib

This page covers Laminaria only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Olaparib page lists 138 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 94 moderate · 41 minor.

From our pharmacist’s overview on the Olaparib page

“Grapefruit is the first thing to drop if you take Olaparib (Lynparza). It blocks CYP3A4, the liver enzyme that clears this cancer drug, so levels can climb and side effects with them.”

Reviewed by 2 · Jul 18, 2026

Open the Olaparib interaction page

One more smart check

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

We hold 229 real supplement products containing Laminaria, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Laminaria. Even though Laminaria itself has no known interaction with Olaparib, 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 Laminaria and Olaparib 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 Laminaria
Top half

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

29 days ago today
Medication Olaparib
Steady interest

#1,512 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 Laminaria reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Laminaria and Olaparib records this page draws on were last updated July 11, 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 Laminaria

What is Laminaria?

  • Source of dietary iodine
  • Thyroid support
  • Cervical dilation (medical procedure)
  • Weight management
  • Digestive and detox supplements
  • General nutrition (vitamins and minerals)

Laminaria is a type of brown seaweed (kelp) that is very rich in iodine and is also used in medical settings as a natural cervical dilator. Because its iodine content can be high and variable, supplements may upset thyroid function, so it should be used cautiously and under professional guidance. Always talk with your pharmacist or doctor before using kelp products, especially if you have a thyroid condition.

Laminaria spp. · Laminariaceae · Whole thallus (dried seaweed/kelp); processed stems used for cervical dilators · Dried seaweed (food), powder, capsules, tablets, and medical cervical dilator sticks

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

Laminaria: dosing

There is no well-established standard supplement dose for Laminaria, and because iodine content varies so much between products, a "safe" amount is hard to define. The main safety limit to keep in mind is total daily iodine intake, which can be easy to exceed with kelp supplements.If you choose to use a kelp product, follow the directions on the label and pick a brand that lists its iodine content and is tested for heavy metals. Do not assume more is better. Medical Laminaria dilators are not dosed by the patient; they are placed and managed entirely by a healthcare professional.

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

Read the full Laminaria monograph & all interactions
Medication

About Olaparib

What Is Olaparib Used For?

Brand name: Lynparza

Lynparza (olaparib) is used to treat adults with certain ovarian, fallopian tube, or primary peritoneal cancers that carry BRCA or other DNA-repair gene mutations — both as a maintenance therapy after platinum-based chemotherapy (including in combination with bevacizumab for some patients) and for recurrent disease. It is also approved for HER2-negative breast cancer with a germline BRCA mutation, both in early high-risk disease (adjuvant setting) and in metastatic disease.

Lynparza is additionally used as maintenance therapy for adults with germline BRCA-mutated metastatic pancreatic adenocarcinoma whose disease has not progressed on first-line platinum-based chemotherapy, and for adults with certain gene-mutated metastatic castration-resistant prostate cancer — either alone (after prior enzalutamide or abiraterone) or in combination with abiraterone and prednisone or prednisolone. All uses require testing for specific genetic mutations using an FDA-approved companion diagnostic before starting treatment.

Most-Reported Side Effects for Olaparib

From FAERS, the FDA’s public side-effect reporting system (20,798 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Malignant neoplasm progression 2,063 reports
Nausea 1,827 reports
Fatigue 1,762 reports
Anemia 1,622 reports
Vomiting 724 reports
See full Olaparib drug information
Keep checking

Other Drugs & Laminaria

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

0Major
69Moderate
0Minor
2,760No known interaction
69 Moderate 2,760 No interaction
Moderate

69 interactions

Showing 60 of 69 moderate interactions — see all 69 on the Laminaria page.

No interaction 2,760 drugs checked — show the list

We also checked Laminaria against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,760 medications checked with no known interaction — see the full Laminaria list.

See the full Laminaria interactions page
See every supplement checked against Olaparib, ranked by severity
Evidence & sources

Laminaria References

The 9 references that drive our Laminaria 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. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  3. Pye KG, Kelsey SM, House IM, et al. Severe dyserythropoeisis and autoimmune thrombocytopenia associated with ingestion of kelp supplement. Lancet 1992;339:1540.
  4. Kazzi GM, Bottoms SF, Rosen MG. Efficacy and safety of Laminaria digitata for preinduction ripening of the cervix. Obstet Gynecol 1982;60:440-3..
  5. Harrell BL, Rudolph AH. Letter: Kelp diet: A cause of acneform eruption. Arch Dermatol 1976;112:560.
  6. Eliason BC. Transient hyperthyroidism in a patient taking dietary supplements containing kelp. J Am Board Fam Pract 1998;11:478-80. PubMed
  7. Norman JA, Pickford CJ, Sanders TW, Waller M. Human intake of arsenic and iodine from seaweed-based food supplements and health foods available in the UK. Food Addit Contam 1988;5:103-9.. PubMed
  8. Amster E, Tiwary A, Schenker MB. Case report: potential arsenic toxicosis secondary to herbal kelp supplement. Environ Health Perspect 2007;115:606-8. PubMed
  9. Miyai K, Tokushige T, Kondo M; Iodine Research Group. Suppression of thyroid function during ingestion of seaweed "Kombu" (Laminaria japonoca) in normal Japanese adults. Endocr J. 2008 Dec;55(6):1103-8. Epub 2008 Aug 9.

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 Laminaria and Olaparib Together: Common Questions

Is it safe to take Laminaria with Olaparib?
We do not list a known interaction between Laminaria and Olaparib. 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.
Do Laminaria and Olaparib have any of the same side effects?
Yes — our sources link each of them separately to 5 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Are Laminaria and Olaparib used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Laminaria in each. That is a conversation for your prescriber, especially if Olaparib is being adjusted to a target.
How was the Laminaria and Olaparib combination checked?
Interactions in our licensed database are recorded against drug classes. Olaparib is filed under 2 classifications, and Laminaria has documented interactions with 6 drug classes — none of Olaparib'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 Laminaria interact with any other medications?
Yes. Laminaria has 69 documented drug interactions in our database — Olaparib 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 Olaparib interact with any supplements?
Yes. Olaparib has documented interactions with 138 supplements in our database — Laminaria is not one of them. The Olaparib interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Laminaria monograph Uses, safety profile, and every drug interaction in one place Olaparib drug information The full plain-English guide to this medication Olaparib supplement interactions Every supplement checked against Olaparib, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 9 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Olaparib and Laminaria?

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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.