Drug & supplement interaction

Flaxseed Oil + Alpelisib

Alpelisib brand name: Piqray.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 13, 2026

The bottom line No known interaction

We found no known interaction between Flaxseed Oil and Alpelisib 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 label for Alpelisib states a food rule worth keeping to, and 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.

Know someone taking this? Share

Facebook Post Reddit Email

On this page

Interaction report

Flaxseed Oil and Alpelisib

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 Alpelisib and Flaxseed Oil 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.

Flaxseed Oil safety at a glance

Flaxseed Oil overall Use caution Generally well tolerated for most adults, but quality and dose vary by product.

Pregnancy Possibly Safe When used orally and appropriately for medicinal purposes, short-term. Although flaxseed oil has been used with apparent safety in clinical research in doses of... Read the full pregnancy detail

Breastfeeding Use caution Limited safety information during breastfeeding, so use only with medical advice.

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 Alpelisib and Flaxseed Oil? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Alpelisib

Interactions in our licensed database are recorded against drug classes, not just single drug names. Alpelisib is filed under 3 classifications — cytochrome p450 2c9 (cyp2c9) inducers, cytochrome p450 3a4 (cyp3a4) substrates, oral drugs. Flaxseed Oil has documented interactions with 3 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate), antihypertensive drugs (moderate) and ezetimibe (zetia) (moderate) — and none of Alpelisib’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

Flaxseed Oil Does Interact With Other Medications

Flaxseed Oil has 293 moderate known drug interactions in our database — Alpelisib isn’t one of them. If you take anything else, check it against the full list below.

Moderate 293 No known interaction 2,537 (incl. Alpelisib)

Taking anything else?

Check Another of Your Medications Against Flaxseed Oil

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

What to actually watch for

No Interaction Found — But Data Suggests Flaxseed Oil and Alpelisib 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. 2 of them are worth acting on rather than waiting out — marked below.

A severe allergic reaction / An allergic reaction Worth acting on Additional detail

Flaxseed Oil

“Orally, flaxseed oil is generally well tolerated. Topically, flaxseed oil seems to be well-tolerated.

Most Common Adverse Effects:

Topically: Itching, redness.

Serious Adverse Effects (Rare):

Orally: Severe allergic reactions such as anaphylaxis.”

Flaxseed Oil · Natural Medicines adverse-effect record, reported in pruritus.

Alpelisib

Listed in the ADVERSE REACTIONS section of the FDA label for Alpelisib. Read the label on DailyMed ›
Dry mouth / Stomach upset / Diarrhea Additional detail
Flaxseed Oil
“Orally, flaxseed oil may cause a change in bowel habits, dry mouth, and dyspepsia when taken at a dose of about 5 grams daily. However, these effects have been reported by only a small number of patients (approximately 3%). High doses of flaxseed oil (30 grams per day and higher) have been associated with loose stools and diarrhea.”

Flaxseed Oil · Natural Medicines adverse-effect record, reported in diarrhea.
3 sources cited

16794. Harper CR, Edwards MC, Jacobson TA. Flaxseed oil supplementation does not affect plasma lipoprotein concentration or particle size in human subjects. J Nutr 2006;136:2844-8. PubMed

5898. Nordstrom DC, Honkanen VE, Nasu Y, et al. Alpha-linolenic acid in the treatment of rheumatoid arthritis. A double-blind, placebo-controlled and randomized study: flaxseed vs. safflower seed. Rheumatol Int 1995;14:231-4. PubMed

11025. Bloedon LT, Szapary PO. Flaxseed and cardiovascular risk. Nutr Rev 2004;62:18-27. DOI
Alpelisib

Listed in the ADVERSE REACTIONS section of the FDA label for Alpelisib. Read the label on DailyMed ›
Itching Additional detail
Flaxseed Oil
“Topically, eye drops containing flaxseed oil may cause redness and itching.”

Flaxseed Oil · Natural Medicines adverse-effect record, reported in pruritus.
1 source cited

101953. Downie LE, Hom MM, Berdy GJ, et al. An artificial tear containing flaxseed oil for treating dry eye disease: A randomized controlled trial. Ocul Surf. 2020;18(1):148-157. PubMed
Alpelisib

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

Effects for Alpelisib come from the ADVERSE REACTIONS section of its FDA label; effects for Flaxseed Oil come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Flaxseed Oil in Pregnancy & Breastfeeding

Pregnancy Possibly Safe

When used orally and appropriately for medicinal purposes, short-term. Although flaxseed oil has been used with apparent safety in clinical research in doses of 1-2 grams daily for up to 6 weeks, some population research has found that consuming flaxseed oil during the second and third trimesters of pregnancy is associated with a four-fold increased risk of premature birth.

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

How to take them

Some Alpelisib Products Have a Food Rule — Flaxseed Oil Should Not Break It

At least one FDA label for a product containing Alpelisib says to take it with food. If you take Flaxseed Oil on an empty stomach out of habit, keep them separate — and take Alpelisib with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Alpelisib products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

2 DOSAGE AND ADMINISTRATION Recommended Dose: Pediatric patients (2 to less than 18 years of age): 50 mg taken orally once daily with food.

From the Dosage and Administration section of the FDA label we read for Alpelisib — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Overlapping uses

What Alpelisib Is Prescribed For, and What Flaxseed Oil Has Been Studied For

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

Alpelisib is prescribed for: Alpelisib is approved for two distinct uses, each tied to a specific brand. Piqray is used in combination with another drug called fulvestrant to treat adults with hormone receptor (HR)-positive, HER2-negative, advanced or metastatic breast cancer whose tumors carry a PIK3CA mutation — and only after the cancer has progressed on or after a hormone-based treatment. A companion diagnostic test is required before starting Piqray. Vijoice is used to treat adults and children 2 years of age and older who have severe manifestations of PIK3CA-Related Overgrowth Spectrum (PROS) — a rare condition where PIK3CA gene mutations cause abnormal tissue, vascular, and bone overgrowth — and who need systemic (whole-body) therapy.

Read the rest of what Alpelisib is prescribed for

Vijoice's approval for PROS was granted under the FDA's accelerated approval pathway based on response data, and continued approval may depend on confirmatory trials.

Flaxseed Oil has been studied for:

Breast cancer studied, not established Flaxseed Oil has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

Flaxseed Oil for breast cancer

It is unclear if oral flaxseed oil reduces the risk of breast cancer.

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 Alpelisib on your own; if you are taking Flaxseed Oil 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 Alpelisib

This page covers Flaxseed Oil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Alpelisib page lists 139 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 · 96 moderate · 40 minor.

From our pharmacist’s overview on the Alpelisib page

“Alpelisib (Piqray) treats PIK3CA-mutated breast cancer, and a drug doing that job leaves little room for supplements that shift its blood level. Yet that is what most of this list does: 121 of the 139 ingredients on file can raise or lower alpelisib through CYP3A4, the liver enzyme that clears it.”

Reviewed by 2 · Jul 18, 2026

Open the Alpelisib interaction page

One more smart check

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

We hold 1,329 real supplement products containing Flaxseed Oil, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Flaxseed Oil. Even though Flaxseed Oil itself has no known interaction with Alpelisib, 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 Flaxseed Oil and Alpelisib 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 Flaxseed Oil

Top 25%

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

29 days ago today

Medication Alpelisib

Steady interest

#1,861 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 Flaxseed Oil reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Flaxseed Oil and Alpelisib 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 Dr. Brian Staiger, PharmD, BCPS.

Supplement

About Flaxseed Oil

What is Flaxseed Oil?

Source of omega-3 (ALA) fatty acids
Heart and cholesterol health
Dry skin and inflammation
Constipation
General wellness

Flaxseed oil is a plant-based source of the omega-3 fatty acid ALA, which the body can partly convert to the omega-3s found in fish oil. It may help support heart health and provide healthy fats, but evidence for most specific health claims is limited or mixed. It is generally well tolerated, but talk to your pharmacist or doctor before starting, especially if you are pregnant or have a bleeding risk.

Linum usitatissimum · Linaceae · Oil pressed from the seeds · Liquid oil, softgel capsules, salad oil

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

Flaxseed Oil: dosing

There is no official standardized dose of flaxseed oil for any health condition. Products vary widely in strength and in how much ALA they provide per serving.The safest approach is to follow the dose printed on the product label and not exceed it without medical advice. To keep the oil fresh, store it as directed (often refrigerated) and avoid using it for cooking at high heat.

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

Read the full Flaxseed Oil monograph & all interactions

Medication

About Alpelisib

What Is Alpelisib Used For?

Brand name: Piqray

Alpelisib is approved for two distinct uses, each tied to a specific brand. Piqray is used in combination with another drug called fulvestrant to treat adults with hormone receptor (HR)-positive, HER2-negative, advanced or metastatic breast cancer whose tumors carry a PIK3CA mutation — and only after the cancer has progressed on or after a hormone-based treatment. A companion diagnostic test is required before starting Piqray.

Vijoice is used to treat adults and children 2 years of age and older who have severe manifestations of PIK3CA-Related Overgrowth Spectrum (PROS) — a rare condition where PIK3CA gene mutations cause abnormal tissue, vascular, and bone overgrowth — and who need systemic (whole-body) therapy. Vijoice's approval for PROS was granted under the FDA's accelerated approval pathway based on response data, and continued approval may depend on confirmatory trials.

See full Alpelisib drug information

Keep checking

Other Drugs & Flaxseed Oil

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

0Major

293Moderate

0Minor

2,536No known interaction

293 Moderate 2,536 No interaction

Moderate

293 interactions

Showing 60 of 293 moderate interactions — see all 293 on the Flaxseed Oil page.

No interaction 2,536 drugs checked — show the list

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

Showing the 60 most looked-up of 2,536 medications checked with no known interaction — see the full Flaxseed Oil list.

See the full Flaxseed Oil interactions page

See every supplement checked against Alpelisib, ranked by severity

Evidence & sources

Flaxseed Oil References

The 21 references that drive our Flaxseed Oil 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.

Kolonel LN, Nomura AM, Cooney RV. Dietary fat and prostate cancer: current status. J Natl Cancer Inst 1999;91:414-28. PubMed
Ramon JM, Bou R, Romea S, et al. Dietary fat intake and prostate cancer risk: a case-control study in Spain. Cancer Causes Control 2000;11:679-85. PubMed
Nordstrom DC, Honkanen VE, Nasu Y, et al. Alpha-linolenic acid in the treatment of rheumatoid arthritis. A double-blind, placebo-controlled and randomized study: flaxseed vs. safflower seed. Rheumatol Int 1995;14:231-4. PubMed
De Stefani E, Deneo-Pellegrini H, Boffetta P, et al. Alpha-linolenic acid and risk of prostate cancer: a case-control study in Uruguay. Cancer Epidemiol Biomarkers Prev 2000;9:335-8.
Giovannucci E, Rimm EB, Colditz GA, et al. A prospective study of dietary fat and risk of prostate cancer. J Natl Cancer Inst 1993;85:1571-9. PubMed
Bloedon LT, Szapary PO. Flaxseed and cardiovascular risk. Nutr Rev 2004;62:18-27. DOI
Laaksonen DE, Laukkanen JA, Niskanen L, et al. Serum linoleic and total polyunsaturated fatty acids in relation to prostate and other cancers: a population-based cohort study. Int J Cancer 2004;111:444-50.. PubMed
Brouwer IA, Katan MB, Zock PL. Dietary alpha-linolenic acid is associated with reduced risk of fatal coronary heart disease, but increased prostate cancer risk: a meta-analysis. J Nutr 2004;134:919-22.
Paschos GK, Magkos F, Panagiotakos DB, et al. Dietary supplementation with flaxseed oil lowers blood pressure in dyslipidaemic patients. Eur J Clin Nutr 2007;61:1201-6. PubMed
Harper CR, Edwards MC, Jacobson TA. Flaxseed oil supplementation does not affect plasma lipoprotein concentration or particle size in human subjects. J Nutr 2006;136:2844-8. PubMed
University of Montreal. Pregnant Women Consuming Flaxseed Oil Have High Risk Of Premature Birth.ScienceDaily, October 29, 2008. Available at: www.sciencedaily.com/releases/2008/10/081027140817.htm (Accessed May 14, 2009).
Allman, M. A., Pena, M. M., and Pang, D. Supplementation with flaxseed oil versus sunflowerseed oil in healthy young men consuming a low fat diet: effects on platelet composition and function. Eur.J Clin.Nutr. 1995;49(3):169-178.
Ursoniu S, Sahebkar A, Andrica F, Serban C, Banach M; Lipid and Blood Pressure Meta-analysis Collaboration Group. Effects of flaxseed supplements on blood pressure: a systematic review and meta-analysis of controlled clinical trial. Clin Nutr. 2016 Jun;3 PubMed
Taghizadeh M, Jamilian M, Mazloomi M, Sanami M, Asemi Z. A randomized-controlled clinical trial investigating the effect of omega-3 fatty acids on vitamin E co-supplementation on markers of insulin metabolism and lipid profiles in gestational diabetes. J
Blackwood DP, LaVallee RK, Al Busaidi A, Jassal DS, Pierce GN. A randomized trial of the effects of ezetimibe on the absorption of omega-3 fatty acids in cardiac disease patients: a pilot study. Clin Nutr ESPEN. 2015 Oct;10(5):e155-e159. PubMed
Morshedzadeh N, Shahrokh S, Aghdaei HA, et al. Effects of flaxseed and flaxseed oil supplement on serum levels of inflammatory markers, metabolic parameters and severity of disease in patients with ulcerative colitis. Complement Ther Med. 2019;46:36-43. PubMed
Downie LE, Hom MM, Berdy GJ, et al. An artificial tear containing flaxseed oil for treating dry eye disease: A randomized controlled trial. Ocul Surf. 2020;18(1):148-157. PubMed
Saleh-Ghadimi S, Kheirouri S, Golmohammadi A, Moludi J, Jafari-Vayghan H, Alizadeh M. Effect of flaxseed oil supplementation on anthropometric and metabolic indices in patients with coronary artery disease: A double-blinded randomized controlled trial. J PubMed
Jamilian M, Tabassi Z, Reiner Z, et al. The effects of n-3 fatty acids from flaxseed oil on genetic and metabolic profiles in patients with gestational diabetes mellitus: a randomised, double-blind, placebo-controlled trial. Br J Nutr. 2020;123(7):792-799
Li L, Li H, Gao Y, Vafaei S, Zhang X, Yang M. Effect of flaxseed supplementation on blood pressure: a systematic review, and dose-response meta-analysis of randomized clinical trials. Food Funct 2023;14(2):675-690. PubMed
Mahmudiono T, Jasim SA, Karim YS, et al. The effect of flaxseed oil consumption on blood pressure among patients with metabolic syndrome and related disorders: A systematic review and meta-analysis of randomized clinical trials. Phytother Res 2022;36(10):

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 Flaxseed Oil and Alpelisib Together: Common Questions

Is it safe to take Flaxseed Oil with Alpelisib?

We do not list a known interaction between Flaxseed Oil and Alpelisib. 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 Flaxseed Oil and Alpelisib have any of the same side effects?

Yes — our sources link each of them separately to 6 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.

Should I take Flaxseed Oil and Alpelisib at the same time of day?

At least one FDA label for a product containing Alpelisib says to take it with food. If you take Flaxseed Oil on an empty stomach out of habit, keep them separate and take Alpelisib with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Alpelisib products can differ — so check the directions on your own box. This is about absorption, not an interaction.

Are Flaxseed Oil and Alpelisib 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 Flaxseed Oil in each. That is a conversation for your prescriber, especially if Alpelisib is being adjusted to a target.

How was the Flaxseed Oil and Alpelisib combination checked?

Interactions in our licensed database are recorded against drug classes. Alpelisib is filed under 3 classifications, and Flaxseed Oil has documented interactions with 3 drug classes — none of Alpelisib'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 Flaxseed Oil interact with any other medications?

Yes. Flaxseed Oil has 293 documented drug interactions in our database — Alpelisib 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 Alpelisib interact with any supplements?

Yes. Alpelisib has documented interactions with 139 supplements in our database — Flaxseed Oil is not one of them. The Alpelisib 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

Flaxseed Oil monograph Uses, safety profile, and every drug interaction in one place Alpelisib drug information The full plain-English guide to this medication Alpelisib supplement interactions Every supplement checked against Alpelisib, 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 21 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Alpelisib and Flaxseed Oil?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.