Drug & supplement interaction

Swamp Milkweed + 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 Swamp Milkweed 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

Swamp Milkweed 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 Swamp Milkweed 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.

Swamp Milkweed safety at a glance

Swamp Milkweed overall Use caution The plant contains toxic sap and cardiac glycoside-like compounds; it is not a well-studied or clearly safe supplement.
Pregnancy Likely Unsafe When used orally due to presence of cardioactive steroids; avoid using. Read the full pregnancy detail
Breastfeeding Likely Unsafe When used orally due to presence of cardioactive steroids; avoid using. 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 Swamp Milkweed? 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. Swamp Milkweed has documented interactions with 7 drug classes — the most serious being digoxin (lanoxin) (major), quinine (major) and corticosteroids (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

Swamp Milkweed Does Interact With Other Medications

Swamp Milkweed has 3 major, 153 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.

Major 3 Moderate 153 No known interaction 2,674 (incl. Olaparib)
Taking anything else?

Check Another of Your Medications Against Swamp Milkweed

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

What to actually watch for

No Interaction Found — But Data Suggests Swamp Milkweed 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.

  • Vomiting reported in 3.5% of FDA reports for Olaparib Additional detail

    Swamp Milkweed

    “Orally, large amounts of swamp milkweed can cause vomiting (18).”

    Swamp Milkweed · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    1 source cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

    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 ›

  • Headache Additional detail

    Swamp Milkweed

    “Orally, the cardiac glycosides in swamp milkweed may cause headache and stupor (18). Visual color disturbances may also occur (18).”

    Swamp Milkweed · Natural Medicines adverse-effect record, reported in cluster headache.

    1 source cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

    Olaparib

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

Reported for Swamp Milkweed but not commonly for Olaparib: an irregular heartbeat.

Effects for Olaparib come from the ADVERSE REACTIONS section of its FDA label; effects for Swamp Milkweed 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

Swamp Milkweed in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Unsafe

When used orally due to presence of cardioactive steroids; avoid using.

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

Everything else you take

See Every Supplement That Interacts With Olaparib

This page covers Swamp Milkweed 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

How much people look this up

Where Swamp Milkweed 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 Swamp Milkweed
Steady interest

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

29 days ago today
Medication Olaparib
Steady interest

#1,886 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 Swamp Milkweed reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Swamp Milkweed and Olaparib records this page draws on were last updated July 10, 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 Swamp Milkweed

What is Swamp Milkweed?

  • Traditional digestive remedy
  • Diuretic (increasing urine)
  • Cough and respiratory complaints
  • Worm or parasite remedy (folk use)
  • Pollinator/garden plant rather than medicine

Swamp Milkweed is a native North American wetland plant best known today as a butterfly and pollinator garden plant, not a proven medicine. It contains toxic milky sap with cardiac glycoside-like compounds, and there is very little reliable human research to support any health use. Because of its potential toxicity, it should not be used as a supplement without professional guidance.

Asclepias incarnata · Apocynaceae · Root, and historically other parts of the plant · Dried root, tinctures, and traditional decoctions (rarely sold as a commercial supplement)

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

Swamp Milkweed: dosing

There is no established safe or standardized dose for Swamp Milkweed. It is not a mainstream supplement, and reliable products with verified content are not generally available.Because of the plant's toxicity and the lack of research, we cannot recommend any specific amount. For most people, the safest approach is to enjoy Swamp Milkweed as a garden plant rather than to consume it.

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

Read the full Swamp Milkweed 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 & Swamp Milkweed

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

3Major
153Moderate
0Minor
2,673No known interaction
3 Major 153 Moderate 2,673 No interaction
Major

3 interactions

Moderate

153 interactions

Showing 60 of 153 moderate interactions — see all 153 on the Swamp Milkweed page.

No interaction 2,673 drugs checked — show the list

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

Showing the 60 most looked-up of 2,673 medications checked with no known interaction — see the full Swamp Milkweed list.

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

Swamp Milkweed References

The 3 references that drive our Swamp Milkweed 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. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
  3. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

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 Swamp Milkweed and Olaparib Together: Common Questions

Is it safe to take Swamp Milkweed with Olaparib?
We do not list a known interaction between Swamp Milkweed 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 Swamp Milkweed and Olaparib have any of the same side effects?
Yes — our sources link each of them separately to 2 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.
How was the Swamp Milkweed and Olaparib combination checked?
Interactions in our licensed database are recorded against drug classes. Olaparib is filed under 2 classifications, and Swamp Milkweed has documented interactions with 7 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 Swamp Milkweed interact with any other medications?
Yes. Swamp Milkweed has 156 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 — Swamp Milkweed 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

Swamp Milkweed 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 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Olaparib and Swamp Milkweed?

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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.