Drug & supplement interaction

Wild Lettuce + Losartan Potassium

Losartan Potassium brand name: Cozaar.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Wild Lettuce and Losartan Potassium 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

Wild Lettuce and Losartan Potassium

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 Losartan Potassium and Wild Lettuce 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.

Wild Lettuce safety at a glance

Wild Lettuce overall Use caution Limited human safety data exist, and high doses have been linked to side effects.
Pregnancy Avoid Not enough safety information is available, so it is best avoided during pregnancy.
Breastfeeding Avoid There is no reliable safety data, so avoid use while breastfeeding.

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

Pharmacist analysis

Studies are few and far between, but the only reported interactions with wild lettuce are with sedative drugs as wild lettuce is purported to have sedative effects.

This would include drugs like antihistamines, opioids, and benzodiazepines. These are detailed on our individual drug interaction pages.

Additionally, as wild lettuce may contain hyoscyamine, an anticholinergic drug, it should be used cautiously with other anticholinergic drugs due to the increased risk of side effects.


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Still wondering about combining Losartan Potassium and Wild Lettuce? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Losartan Potassium

Interactions in our licensed database are recorded against drug classes, not just single drug names. Losartan Potassium is filed under 7 classifications — including angiotensin receptor blockers (arbs), cytochrome p450 2c9 (cyp2c9) substrates, antihypertensive drugs. Wild Lettuce has documented interactions with 2 drug classes — the most serious being anticholinergic drugs (moderate) and cns depressants (moderate) — and none of Losartan Potassium’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

Wild Lettuce Does Interact With Other Medications

Wild Lettuce has 393 moderate known drug interactions in our database — Losartan Potassium isn’t one of them. If you take anything else, check it against the full list below.

Moderate 393 No known interaction 2,437 (incl. Losartan Potassium)
Taking anything else?

Check Another of Your Medications Against Wild Lettuce

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

What to actually watch for

No Interaction Found — But Data Suggests Wild Lettuce and Losartan Potassium 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.

  • An allergic reaction Worth acting on Additional detail

    Wild Lettuce

    “Topically, wild lettuce can cause contact dermatitis (4). It can cause an allergic reaction in individuals sensitive to the Asteraceae/Compositae family. Members of this family include ragweed, chrysanthemums, marigolds, daisies, and many other herbs.”

    Wild Lettuce · Natural Medicines adverse-effect record, reported in dermatitis.

    1 source cited
    1. 4. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.

    Losartan Potassium

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

  • Ringing in the ears Additional detail

    Wild Lettuce

    “There is currently a limited amount of information on the adverse effects of wild lettuce. Orally, large amounts of wild lettuce, as well as eating prematurely harvested wild lettuce, can cause sweating, increased respiration, tachycardia, pupil dilation, dizziness, ringing in the ears, vision disorders, pressure in the head, somnolence, excitatory states (18, 93563), respiratory depression, coma, and death (4).

    Topi…”

    Wild Lettuce · Natural Medicines adverse-effect record, reported in cluster headache.

    2 sources cited
    1. 4. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
    2. 93566. Mullins ME, Horowitz BZ. The case of the salad shooters: intravenous injection of wild lettuce extract. Vet Hum Toxicol. 1998;40(5):290-1.

    “Orally, large amounts of wild lettuce or prematurely harvested wild lettuce has been reported to cause mydriasis, pupil dilation, dizziness, ringing in the ears, and vision disorders (18,93563).”

    Wild Lettuce · Natural Medicines adverse-effect record, reported in vertigo.

    2 sources cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    2. 93563. Besharat S, Besharat M, Jabbari A. Wild lettuce (Lactuca virosa) toxicity. BMJ Case Rep. 2009;2009. pii: bcr06.2008.0134.

    Losartan Potassium

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

  • A fast or pounding heartbeat Additional detail

    Wild Lettuce

    “Intravenously, boiled wild lettuce, prepared by hand in combination with valerian root, has been reported to cause fever, severe headache, and tachycardia in three intravenous drug users. This reaction was hypothesized to be due to an immunologic response.”

    Wild Lettuce · Natural Medicines adverse-effect record, reported in cluster headache.

    1 source cited
    1. 93566. Mullins ME, Horowitz BZ. The case of the salad shooters: intravenous injection of wild lettuce extract. Vet Hum Toxicol. 1998;40(5):290-1.

    Losartan Potassium

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

  • Drowsiness / Dizziness / Headache reported in 4.9% of FDA reports for Losartan Potassium Additional detail

    Wild Lettuce

    “Orally, large amounts of wild lettuce or prematurely harvested wild lettuce has been reported to cause dizziness, pressure in the head, somnolence, anxiety, headache, excitatory states (18, 93563), and coma (4).”

    Wild Lettuce · Natural Medicines adverse-effect record, reported in anxiety.

    1 source cited
    1. 4. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.

    Losartan Potassium

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

  • Stomach pain / Nausea reported in 5.9% of FDA reports for Losartan Potassium Additional detail

    Wild Lettuce

    “Orally, wild lettuce has been reported to cause nausea, vomiting, and abdominal cramps.

    Intravenously, boiled wild lettuce, prepared by hand in combination with valerian root, has been reported to cause nausea and abdominal pain in three intravenous drug users.”

    Wild Lettuce · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    2 sources cited
    1. 93563. Besharat S, Besharat M, Jabbari A. Wild lettuce (Lactuca virosa) toxicity. BMJ Case Rep. 2009;2009. pii: bcr06.2008.0134.
    2. 93566. Mullins ME, Horowitz BZ. The case of the salad shooters: intravenous injection of wild lettuce extract. Vet Hum Toxicol. 1998;40(5):290-1.

    Losartan Potassium

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

  • A skin rash Additional detail

    Wild Lettuce

    Recorded for Wild Lettuce in the same Natural Medicines adverse-effect record shown under Ringing in the ears above.

    Losartan Potassium

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

  • Vomiting Additional detail

    Wild Lettuce

    Recorded for Wild Lettuce in the same Natural Medicines adverse-effect record shown under Stomach pain / Nausea above.

    Losartan Potassium

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

Reported for Wild Lettuce but not commonly for Losartan Potassium: trouble passing urine, sweating, flushing and anxiety or restlessness.

Effects for Losartan Potassium come from the ADVERSE REACTIONS section of its FDA label; effects for Wild Lettuce come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 89,498 voluntary FDA FAERS reports for Losartan Potassium 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.

From our Q&A

Questions About Wild Lettuce or Losartan Potassium

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Wild Lettuce or Losartan Potassium, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Losartan Potassium

This page covers Wild Lettuce only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Losartan Potassium page lists 253 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Grapefruit (major) and St. John's Wort (major).

By severity: 6 major · 205 moderate · 42 minor.

From our pharmacist’s overview on the Losartan Potassium page

“Losartan potassium (Cozaar) treats high blood pressure, and this is a list to respect, because six of its 253 supplement interactions carry a major rating. Most entries do one of two things.”

Reviewed by 2 · Jul 18, 2026

Open the Losartan Potassium interaction page

One more smart check

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

We hold 99 real supplement products containing Wild Lettuce, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Wild Lettuce. Even though Wild Lettuce itself has no known interaction with Losartan Potassium, 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 Wild Lettuce and Losartan Potassium 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 Wild Lettuce
Steady interest

#1,173 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Losartan Potassium
Top 10

#6 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 Wild Lettuce reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Wild Lettuce and Losartan Potassium 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 Wild Lettuce

What is Wild Lettuce?

Wild Lettuce
  • Insomnia and trouble sleeping
  • Anxiety and restlessness
  • Pain relief
  • Cough and respiratory symptoms
  • Muscle spasms

Wild lettuce is a traditional herb used mainly for sleep, anxiety, and pain, but solid human research supporting these uses is very limited. Because its safety is not well studied, it should be used cautiously, avoided in pregnancy and breastfeeding, and discussed with your pharmacist or doctor first.

Lactuca virosa · Asteraceae · Leaves, dried milky sap (latex/lactucarium), and aerial parts · Capsules, tablets, dried herb, tea, tincture, extract, and smoking/vaping preparations

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

Wild Lettuce: dosing

There is no well-established or standardized dose for wild lettuce. The right amount can vary widely depending on the product, form (tea, capsule, tincture, or extract), and how it is prepared.Because a safe and effective dose has not been clearly defined in research, the best approach is to follow the directions on the product label and start with the lowest suggested amount.

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

Read the full Wild Lettuce monograph & all interactions
Medication

About Losartan

What Is Losartan Used For?

Brand name: Cozaar

Losartan tablets — available as branded Cozaar and several generic products — are used to treat high blood pressure (hypertension) in adults and children 6 years and older. Lowering blood pressure reduces the risk of strokes and heart attacks. Losartan tablets are also used to reduce the risk of stroke in people with high blood pressure who also have left ventricular hypertrophy (an enlarged left side of the heart). Note: evidence suggests this stroke-risk benefit may not apply to Black patients.

Losartan tablets are additionally approved to protect the kidneys in people with type 2 diabetes, high blood pressure, and signs of kidney damage (diabetic nephropathy). Arbli, the oral suspension form, shares these same approved uses.

Most-Reported Side Effects for Losartan Potassium

From FAERS, the FDA’s public side-effect reporting system (89,498 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 6,464 reports
Nausea 5,301 reports
Diarrhea 5,184 reports
Dyspnea 4,689 reports
Dizziness 4,429 reports
See full Losartan drug information
Keep checking

Other Drugs & Wild Lettuce

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

0Major
393Moderate
0Minor
2,436No known interaction
393 Moderate 2,436 No interaction
Moderate

393 interactions

Showing 60 of 393 moderate interactions — see all 393 on the Wild Lettuce page.

No interaction 2,436 drugs checked — show the list

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

Showing the 60 most looked-up of 2,436 medications checked with no known interaction — see the full Wild Lettuce list.

See the full Wild Lettuce interactions page
See every supplement checked against Losartan Potassium, ranked by severity
Evidence & sources

Wild Lettuce References

The 5 references that drive our Wild Lettuce 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. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  3. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  4. Besharat S, Besharat M, Jabbari A. Wild lettuce (Lactuca virosa) toxicity. BMJ Case Rep. 2009;2009. pii: bcr06.2008.0134.
  5. Mullins ME, Horowitz BZ. The case of the salad shooters: intravenous injection of wild lettuce extract. Vet Hum Toxicol. 1998;40(5):290-1.

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 Wild Lettuce and Losartan Potassium Together: Common Questions

Is it safe to take Wild Lettuce with Losartan Potassium?
We do not list a known interaction between Wild Lettuce and Losartan Potassium. 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 Wild Lettuce and Losartan Potassium have any of the same side effects?
Yes — our sources link each of them separately to 10 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 Wild Lettuce and Losartan Potassium combination checked?
Interactions in our licensed database are recorded against drug classes. Losartan Potassium is filed under 7 classifications, and Wild Lettuce has documented interactions with 2 drug classes — none of Losartan Potassium'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 Wild Lettuce interact with any other medications?
Yes. Wild Lettuce has 393 documented drug interactions in our database — Losartan Potassium 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 Losartan Potassium interact with any supplements?
Yes. Losartan Potassium has documented interactions with 253 supplements in our database — Wild Lettuce is not one of them. The Losartan Potassium 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

Wild Lettuce monograph Uses, safety profile, and every drug interaction in one place Losartan drug information The full plain-English guide to this medication Losartan Potassium supplement interactions Every supplement checked against Losartan Potassium, 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 5 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Losartan Potassium and Wild Lettuce?

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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.