Herb & supplement monograph

Wild Lettuce Drug Interactions, Uses, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Wild Lettuce interacts with medications. The heart of this page is the interaction list — every drug Wild Lettuce is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Wild Lettuce is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Wild Lettuce Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Wild Lettuce drug interaction appears low for most people. None of the listed interactions are rated major, and while many medications carry a moderate rating, all of them rest on limited or theoretical evidence rather than well-documented human studies.

Interactions deserving the most attention

The combinations worth the most care involve sedating medications, such as sleep aids, anxiety medicines, and opioids, because wild lettuce may add to their drowsiness and slow thinking. Also watch anticholinergic medications, which cause effects like dry mouth and constipation. Evidence conflicts on whether wild lettuce contains a meaningful amount of an anticholinergic compound, but people who ate large amounts have reported dry mouth, constipation, dizziness, and sweating, so combining the two could add up.

What the rest of the list means

The long list of medications reflects just two broad concerns, sedation and anticholinergic effects, applied across many drugs. Most of these pairings are theoretical, and none have been confirmed as harmful in controlled human studies. A high count here signals caution with certain drug types, not proven danger with every medicine listed.

Check your medications against Wild Lettuce

Based on HelloPharmacist’s Wild Lettuce interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Wild Lettuce

393 medications have a known interaction with Wild Lettuce, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Wild Lettuce using our pharmacist-reviewed interaction data.

AI summaries are generated from our Wild Lettuce interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Wild Lettuce combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Wild Lettuce affects

Every type of medication (drug category) Wild Lettuce is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 2 drug categories Wild Lettuce interacts with

Anticholinergic DrugsCns Depressants

Anticholinergic Drugs

Studies report varying evidence on whether or not wild lettuce contains hyoscyamine, an anticholinergic drug. If it does, it appears to be in very low amounts. Nevertheless, there have been case reports of individuals consuming large amounts of wild lettuce experiencing anticholinergic-related side effects, such as constipation, dry mouth, dizziness, and sweating. Therefore, if you are already taking a drug with anticholinergic effects, you should be cautious about combining it with wild lettuce as the risk of side effects may be increased.

Likelihood Possible Evidence D

Cns Depressants

Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.

Likelihood Possible Evidence D

Monograph

Wild Lettuce: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

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.

Scientific name: Lactuca virosa
Family: Asteraceae
Part used: Leaves, dried milky sap (latex/lactucarium), and aerial parts
Common forms: Capsules, tablets, dried herb, tea, tincture, extract, and smoking/vaping preparations

People commonly use it for

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

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Limited human safety data exist, and high doses have been linked to side effects.

PregnancyInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Wild lettuce (Lactuca virosa) is a tall plant in the daisy and lettuce family. It is native to parts of Europe and Asia and is related to the lettuce you eat in salads, though it is more bitter and not grown as a food.

When the stem or leaves are cut, the plant releases a milky white sap. This dried sap is sometimes called lactucarium or "opium lettuce." Despite that nickname, wild lettuce does not contain opium or opioids. The name comes from its long-standing folk use as a calming, sleep-promoting, and pain-easing remedy.

Today people use wild lettuce as a tea, capsule, tincture, or smoking herb, mostly hoping for help with sleep, anxiety, or pain. It has a long history in traditional medicine, but modern scientific study of it is still very limited.

Uses & effectiveness

Wild lettuce is popularly used for several conditions, but the evidence supporting these uses is weak. Most of what we know comes from traditional use, laboratory studies, or animal research rather than from well-designed human trials.

Sleep and anxiety: Wild lettuce is most often taken as a mild sedative for insomnia and restlessness. Animal studies suggest some calming effects, but there is little quality human research to confirm it works.

Pain: It is traditionally used to ease pain, including headaches and muscle aches. Some early animal research points to pain-relieving activity, but this has not been clearly proven in people.

Cough and spasms: Folk medicine has used it to calm coughs and muscle spasms. Again, strong human evidence is lacking.

Overall, wild lettuce should be considered unproven for these uses. It may help some people feel relaxed, but you should not rely on it in place of treatments your doctor recommends.

How it works

Wild lettuce contains bitter compounds called sesquiterpene lactones, the best known being lactucin and lactucopicrin. These are found in the milky sap and are thought to be responsible for its calming and possible pain-relieving effects.

In laboratory and animal studies, these compounds have shown sedative and mild pain-easing activity. The plant may act on the nervous system to produce a relaxing effect, but the exact mechanisms in humans are not well understood.

It is important to know that wild lettuce does not contain opioids and does not work like morphine, even though it is nicknamed "opium lettuce." Most of the proposed actions are based on early research and have not been confirmed in people.

Safety & precautions

Wild lettuce has been used traditionally, but its safety has not been carefully studied in modern research. Because of this, it should be used with caution.

People who should be especially careful or avoid it include those with allergies to plants in the daisy/ragweed family (Asteraceae), people with glaucoma or other eye problems, and anyone taking medicines that cause drowsiness. Do not drive or operate machinery if it makes you sleepy.

Pregnancy and breastfeeding: There is not enough reliable safety information for these groups. To be safe, wild lettuce should be avoided during pregnancy and while breastfeeding.

Always talk with your pharmacist or doctor before starting wild lettuce, especially if you have a health condition or take other medications or supplements.

Side effects

At typical amounts, wild lettuce may cause mild side effects such as drowsiness, dizziness, dry mouth, or stomach upset. Some people may have allergic reactions, especially if they are sensitive to ragweed, marigolds, daisies, or related plants.

Large doses have been linked to more serious problems, including a fast heartbeat, breathing difficulty, dizziness, ringing in the ears, dilated pupils, and confusion. Very high amounts could be dangerous, so it should not be taken in excess.

Stop using wild lettuce and seek medical care if you have signs of an allergic reaction (such as rash, swelling, or trouble breathing) or any severe or unusual symptoms.

Wild Lettuce: Reported Adverse Effects

Documented safety reports on Wild Lettuce from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

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, respiratory depression, coma, and death.

Topically, wild lettuce can cause contact dermatitis.

Intravenously, boiled wild lettuce has been reported to cause fever, severe headache, tachycardia, nausea, and abdominal pain in three intravenous drug users.

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

Reports by condition

Anxiety Neurologic/CNS

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, and coma.

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

Cluster headache Immunologic

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.

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

Depression Pulmonary/Respiratory

Orally, large amounts of wild lettuce or prematurely harvested wild lettuce has been reported to cause increased respiration or respiratory depression.

Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.

Dermatitis Dermatologic

Topically, wild lettuce can cause contact dermatitis. 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.

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

Nausea and vomiting Gastrointestinal

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.

Niacin-induced flushing Cardiovascular

Orally, large amounts of wild lettuce or prematurely harvested wild lettuce has been reported to cause sweating, flushing, and tachycardia.

Urinary retention Genitourinary

Orally, wild lettuce can cause urinary retention.

Besharat S, Besharat M, Jabbari A. Wild lettuce (Lactuca virosa) toxicity. BMJ Case Rep. 2009;2009. pii: bcr06.2008.0134.

Vertigo Ocular/Otic

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.

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

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.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

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. Avoid taking more than recommended, since high doses have been linked to harmful effects.

Check with your pharmacist or doctor before using wild lettuce so they can help you decide whether it is appropriate and how to use it safely.

Pregnancy & Breastfeeding

Wild Lettuce & Pregnancy

Insufficient reliable information

Insufficient reliable information available; avoid using.

Wild Lettuce & Breastfeeding

Insufficient reliable information

Insufficient reliable information available; avoid using.

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

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.

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

Keep reading

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.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

Brand directory

Brands that make products with Wild Lettuce

48 brands in our database make a supplement containing Wild Lettuce.

Amazon Therapeutics 45 products Bio Nutrition 61 products BioGenesis Nutraceuticals 87 products Buried Treasure Liquid Nutrients 73 products Christopher's Original Formulas 140 products Crystal Star 123 products Dr. Rico Perez 49 products Earthborn Elements 176 products Enzymatic Therapy 675 products Enzymatic Therapy Fatigued to Fantastic! 18 products Everyday Health 69 products Gaia Herbs 700 products Gaia Herbs Curcumin Synergy 22 products Gaia Herbs Professional Solutions 145 products Hawaii Pharm 4,726 products Herbal Goodness 93 products Herbal Terra 3,138 products Herbalife 205 products Herbalife Nutrition 74 products Herbalist & Alchemist 613 products Hi-Tech Pharmaceuticals 106 products HoltraCeuticals 143 products Indiana Botanic Gardens 941 products Integrative Therapeutics 941 products

Product directory

Supplement products with Wild Lettuce

100 products in our database contain Wild Lettuce. Open any to see its full ingredient list and every drug interaction we check.

Pharmacist Counseling Corner

Wild Lettuce: Common Questions

Does Wild Lettuce interact with prescription medications?

Yes. We list 393 medications with a known interaction with Wild Lettuce. Use the checker above to see how Wild Lettuce interacts with a specific drug.

How are Wild Lettuce interactions rated?

Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.

Is it safe to take Wild Lettuce with my medications?

It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.

Where does this Wild Lettuce interaction information come from?

Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.

What is Wild Lettuce used for?

People most commonly use Wild Lettuce as a mild sedative for sleep, anxiety, and pain, as well as for coughs and muscle spasms. However, strong human evidence supporting these uses is lacking.

Does Wild Lettuce contain opium or opioids?

No. Despite the nickname "opium lettuce," Wild Lettuce contains no opium or opioids. The nickname comes from its milky sap and its traditional use as a calming, pain-easing herb.

Is Wild Lettuce safe to take?

Its safety has not been well studied. Mild side effects like drowsiness are possible, and large doses have been linked to more serious problems, so it should be used cautiously and discussed with your pharmacist or doctor.

Can I use Wild Lettuce while pregnant or breastfeeding?

No. There is not enough reliable safety information, so Wild Lettuce should be avoided during pregnancy and while breastfeeding.

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

Keep exploring

Products that contain Wild Lettuce

A rotating sample of real supplements in our database that list Wild Lettuce — open any to see its full ingredients and every drug interaction we check.

See all 100 products with Wild Lettuce →

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Wild Lettuce Drug Interactions, Uses, Safety & More

Your Choice:

Wild Lettuce Drug Interactions: The Bottom Line

Drugs that interact with Wild Lettuce

Don’t want to scroll the list? Just ask.

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Likelihood — How Well It’s Documented

Where This Data Comes From

The kinds of drugs Wild Lettuce affects

Wild Lettuce: Uses, Safety & Side Effects

Overview

Uses & effectiveness

How it works

Safety & precautions

Side effects

Wild Lettuce: Reported Adverse Effects

Dosing

Wild Lettuce & Pregnancy

Wild Lettuce & Breastfeeding

References & further reading

Brands that make products with Wild Lettuce

Supplement products with Wild Lettuce

Wild Lettuce: Common Questions

Related supplements & herbs

Products that contain Wild Lettuce

Have a question about Wild Lettuce?