I was told about the amazing medicinal qualities of wild lettuce recently, and my immediate vocal reaction was “that’s interesting, I’ll have to do a little research.” What I didn’t say out loud, but was thinking, was which species? As it turns out, my internal commentary was the bit I should have said out loud, because that’s the important part… There are 50 species of wild lettuce, possibly more, and they grow in locations around the world. But the interwebs information on the possible pharmacological import of the ‘wild lettuce’ rarely differentiates between species, making it mostly useless. Because species is important, especially in such a diverse group of plants. Not all will possess the qualities attributed to it, some will be toxic, and others will be harmless (thank goodness). So… Lactuca sativa, which is found in the wild in places like Turkey, is the common everyday lettuce you find in the grocery here in America. I know I have readers worldwide, but as this conversation took place in the good old US of A, I’ll direct the post mostly to this area. Lactuca canadensis is the common yellow-flowered wild lettuce of North America. Lactuca virosa, which grows wild in Europe and parts of the Middle East, and may be found in southern parts of the US as an invasive species, is the wild lettuce commonly believed to have medicinal properties.

Yesterday, Mom gave me a link to what WebMD has to say about it. If you’ll note, there is no specific identification of which species, or indeed, how to identify the plant accurately.

wild lettuce

What aren’t you seeing there? You aren’t seeing any actual scientific data. If you were to click onto the tabs at the top – which I’m going to guess most people don’t do, you would find that it says there is insufficient evidence for any of these claims. I wonder how many would pay attention to the side effects? “Wild lettuce seems safe for most people in small amounts. Large amounts, however, can slow breathing and might cause death.
Applying wild lettuce directly to the skin can cause irritation. Large amounts can cause sweating, fast heartbeat, pupil dilation, dizziness, ringing in the ears, vision changes, sedation, breathing difficulty, and death.”  So what is a small amount? A large amount? Those are quite vague terms, especially when it comes to drugs (and yes, this is a drug as it’s being used here). The last tab over includes this: “At this time there is not enough scientific information to determine an appropriate range of doses for wild lettuce. Keep in mind that natural products are not always necessarily safe and dosages can be important.” 

Moving away from a popular ‘medical’ site, into actual studies done on the potential of the various wild lettuces, we find that no central analgesic (pain relief) effect is found from the seeds, although it is a common folk remedy in Turkey and surrounding areas. Despite the common name ‘opium lettuce’ and the ascription of properties similar to morphine to the wild lettuces, there is no opiate property seen on injection. As a matter of fact, as far back as the 1930s, scathing summaries of the lack of evidence for any opioid properties were available (but seem to have been ignored). The attribution of the opiate property seems to have been largely based on the smell, since the sap of the lettuce, collected and dried, seems to have smelled like that of the morphine poppy. Not a good basis for medicine. L. sativa (again, this is the domestic lettuce) stem extract was shown to have a sedative effect in toads. I’m not sure that toads are a good model organism for humans, but you should also note that high doses cause heart arrhythmia. There is insufficient evidence, however, to indicate that wild lettuce is useful for insomnia.

If you are interested in natural remedies, at a minimum, do more research into them than WebMD. I highly suggest trying Google Scholar to begin with, rather than the open Web. You’ll get less (note I am not saying none!) of the flaky sites trying to sell you something. Try searching for paired terms like ‘wild lettuce pharmokinetics’ or ‘wild lettuce toxicity’ in order to find results specific to medicinal uses. When you do this, you’ll find articles like this one, detailing the toxic effects of wild lettuce on three people who consumed it, fortunately with no long-lasting effects other than some time in the hospital being very ill. You might also find a large, very useful, review of many natural supplements and herbs, detailing their interactions with the human system and other drugs. This is important: any drugs have the potential to interact in bad ways with one another, and I’ll remind you again, any substance you use for medicine, no matter if you picked it yourself, is a drug.

I am not saying ‘don’t do it!’ what I am saying is ‘proceed with caution.’ Wild lettuce (L. canadensis) native to the Americas, is not shown to possess the active pharmaceutical ingredients of L. sativa or L. virosa (which means, by the way, toxic). It is known to be edible at some stages of development, so drinking it as a tea will probably not hurt in moderation. Probably… but be absolutely certain of your identification of the plant before you harvest. Do your due diligence to check for any interactions with any prescribed medicines, natural supplements, or other herbs you are taking, before consuming an unknown substance. Be sure to let your doctor know everything you are taking or using, not just the stuff in the bottles with a label. Wild lettuce can cause uncontrollable bleeding if taken incorrectly (see above review of supplements). It can also be toxic, taken in excess or at the wrong time of year. Self-medication is a dangerous road, so tread lightly. On the other hand, the placebo effect of the human mind is a strange and wondrous thing, so if you find relief, enjoy that. Just don’t overdo it.




28 responses to “Wild Lettuce”

  1. Lol. This makes me wanna think twice before buying lettuce in the grocery store. First romaine, now this? 🙂 Reminds me of the joke that says that states life is a sexually transmitted disease for which there is no cure. It always ends in death.

  2. Interesting. I tend not to want to consume anything that can be picked wild unless I know exactly what it is and what it does. I will take plantain (the leafy plant, not the banana relative) and rub it on a bug bite if I’m out in the yard because I read somewhere that it stops the itch and thought ‘what could it hurt to try’. I tried and it does what it says it does. But I grew up around plantain and it never bothered me before, so I did have a baseline. I would never actually eat it, though, even though some places say you can. Umm, nope.

    1. And I’ve been eating wild plants and animals since I was small. But I am very cautious about it – I want to be utterly certain of my ID before I eat it or feed it to my family.

  3. Oooh, I wonder if that’s the basis of the famous “Soporific effect” of lettuces on the Flopsey Bunnies…..

    1. Almost certainly. It was commonly known as a sedative based on the tenuous connection to the opium poppy.

  4. Eh, my issues with the companies producing drugs is that they’re in it for money (they’re run by human after all) with all the problems that come along with that, but I don’t believe they’re hiding a cure for cancer or the like, cause if they were they know damn well they could make fortune off of it.

    1. And I’m not saying you should only buy Big Pharma drugs. But I work in quality control, and I’m acutely aware of the danger in not having it. Or, in random claims made with no data to back them whatsoever.

  5. I happen to have a PDF copy of the Handbook of Medicinal Herbs (CRC Press).
    Page 779:
    WILD LETTUCE (Lactuca virosa L.) ++

    Activities (Wild Lettuce)

    Allergenic (1; CAN); Analgesic (1; APA; CRC; FAD; PHR; PH2);
    Anaphrodisiac (f; MAD); Antispasmodic (1; CAN; PHR; PH2); Antitussive (f; CRC); Candidicide (1; APA); CNS Depressant (f; APA); Collyrium (f; CRC); Dermatitigenic (f; FAD); Diaphoretic (f; CRC); Diuretic (f; CRC; FAD; MAD); Emmenagogue (f; MAD); Expectorant (f; CRC); Fungicide (1; APA); Hallucinogen (f; APA); Hypnotic (f; CAN; CRC); Hypotensive (1; APA); Lactagogue (f; CRC; FAD); Laxative (f; CRC); Narcotic (f; PHR; PH2); Nervine (f; FAD);
    Poison (f; CRC); Sedative (1; APA; CAN; FAD; MAD); Soporific (f; APA; CRC); Tonic (f;
    FAD); Tranquilizer (f; PHR).

    Indications (Wild Lettuce)

    Acne (f; FAD); Arthrosis (f; CAN); Asthma (f; CRC; PHR; PH2);
    Atherosclerosis (f; CRC; HHB; PHR; PH2); Blennorrhea (f; MAD); Bronchosis (f; PHR; PH2);
    Cancer (f; CRC); Candida (1; APA); Catarrh (f; PH2); Colic (f; CRC); Constipation (f; CRC);
    Cough (f; APA; CAN; PHR; PH2); Cramp (1; CAN; MAD; PHR; PH2); Cystosis (f; MAD);
    Dermatosis (f; FAD); Dropsy (f; CRC; MAD); Dysmenorrhea (f; CAN); Dyspnea (f; MAD);
    Dysuria (f; CRC; PH2); Fever (f; CRC); Fungus (1; APA); Gout (f; CRC); Hepatosis (f; CRC;
    HHB; PH2); High Blood Pressure (1; APA); Hyperkinesis (f; CAN); Infection (1; APA); Insomnia (1; APA; CAN; FAD; MAD); Jaundice (f; CRC); Laryngosis (f; CRC; MAD; PH2); Mycosis (1; APA); Myosis (f; CAN); Nervousness (1; APA; CAN; FAD; MAD; PHR); Nymphomania (f; CAN); Ophthalmia (f; MAD); Pain (1; APA; CAN; CRC; FAD; MAD; PHR; PH2); Pertussis (f; CAN; CRC; PHR; PH2); Poison Ivy (f; FAD); Priapism (f; CAN; MAD); Rheumatism (f; APA); Scrofula (f; MAD); Spermatorrhea (f; MAD); Strangury (f; CRC); Swelling (f; HHB; PH2); Tracheosis (f; CRC; HHB; PH2); UTI (f; PHR); Wart (f; FAD); Water Retention (f; CRC; FAD; MAD); Yeast (1; APA).

    Dosages (Wild Lettuce) — 0.5–3 g dry leaf, or in tea, 3 ×/day (CAN); 0.3–1 g soft leaf extract
    (CAN); 0.5–3 ml liquid leaf extract (1:1 in 25% ethanol) 3 ×/day (CAN); 0.3–1 g lactucarium
    (dried latex) 3 ×/day (CAN; HHB; MAD).

    Contraindications, Interactions, and Side Effects (Wild Lettuce)

    Class 1 (AHP) but class 2b. Australians council against exceeding dosage. Contraindicated in BPH and glaucoma (AHP).
    “Hazards and/or side effects not known for proper therapeutic dosages” (PH2) (but PH2 designates no specific quantified dosage! JAD). I do not believe the CAN listing of hyoscyamine (usually in Solanaceae), nor morphine (only in poppy) in wild or tame lettuce. Lettuce may contain allergenic sesquiterpenes. Overgrazing on immature wild lettuce has caused dyspnea, pulmonary emphysema, and weakness in cattle. In view of the lack of toxicological data, and the possible allergic activity, excessive use, especially during lactation and pregnancy, should be avoided. Overdoses may cause coma, depressed respiration, dizziness, mydriasis, stupor, tachycardia, tinnitus, and even death (CAN; PH2). Lactucarium is mydriatic; Lactucin and lactupicrin are sedatives, but do not readily cross the blood-brain barrier.

    1. thank you! Do you know what the copyright date is on that? I’m curious if any of the studies on efficacy were done after that was written.

      1. From Amazon,
        Hardcover: 896 pages
        Publisher: CRC Press; 2 edition (June 27, 2002)
        Language: English
        ISBN-10: 0849312841
        ISBN-13: 978-0849312847

        They only want $309 for the hardcover, (As low as $47.31 used.)
        Or you can get the Kindle edition for a mere $293.55.

  6. My gift-from_God, happily-ever-after trophy wife Vanessa, the elegant, foxy, praying black grandmother of Woodstock, GA, is likely to present me with a recommendation for wild lettuce sometime in the next six months. Somebody at work will recommend it, or she’ll see an article somewhere, and I always tell her that it’s ganja and then she hits me with a coffee cup.
    We have an adult daughter who is even worse about this sort of thing, because she goes to the gym every morning, and people there tell her things. It’s kind of goofy to me, because she is in GREAT shape and has zero health conditions, and yet she usually has a bottle of goop in the refrigerator and a bag or box of some nasty vegetable matter in the freezer.
    And yet, these things won’t KILL you, unlike that silver fad that went around a few years back.
    Oh, yeah: quality control is for wimps. When >I< was a youth, we used to buy unknown substances, purported to make you feel good, from random strangers on the street and then inject it into our bloodstream with water from a bathroom faucet. That was the 60s, baby!

    1. Augghh! *Shudders* the infections…

      1. Well, as a college freshman, I was already taking courses from ‘Staff,’ so I was prepared.
        Besides, 103 degree fevers from infection and jaundice from hepatitis were all a part of the mystique of the lifestyle.
        Quality control is for people who can’t handle sustained self-administration of misery and paranoia.

    2. Orvan Taurus Avatar
      Orvan Taurus

      Ah, the ‘natural is good’ mentality… I suppose that all-natural hemlock stuff does put an end to pain… but I have my doubts about it being good medicine.

      1. How ’bout all-natural amanitas? Or slightly less lethal, all-natural poison ivy, Now! With more urushiol!!!

        1. Oleander.

          I have my kids rightly scared silly of it.

          1. I trained my kids early on not to eat berries I hadn’t said were ok. There are so many that look appealing, but aren’t.

            1. There is a family story that, way back when my Mother first moved to Arizona, she ate some of the seeds from a Bird of Paradise plant, and it darned near killed her. (Grain of salt, here, she had a microbiology BS already. I think the “family story” was a tale made up to keep her kids from doing that particular stupid thing.)

              Many things depend on preparation, of course – you can eat mesquite seeds – if you know when to harvest, and how to roast them properly before grinding. Then there is the fact that you can, with a ten pound bag of Idaho potatoes, make several nice healthy (if rather carb-heavy) side dishes of mashed potatoes – or poison yourself with solanine (a nerve toxin).

              Oddly enough, my family had a habit of eating the peels of baked potatoes, where most of the toxin forms – and it is not destroyed by the heat of cooking. References that I just looked at say that the solanine in as little as 100 grams of peels will cause symptoms to appear in most people – but I recall no ill effects at all.

            2. You won’t find much solanine, even in the peels, unless they are green.

            3. I would guess it was either a “can contain” thing, or they’re being very strict about the peel measurement– like, “was removed from potato with sand paper.” A large potato is, per quick internet search, about 300g; so picture about a cup of brown skin sludge when you get maybe half a tablespoon per potato…..

            4. I suspect ‘can contain’ is more likely. The study I found on quick search is looking at solanine production when a potato is exposed to light, and found that there could be as much as 50 mg/100 g of peel. In the 1970s the total glycoalkaloid content (including but not limited to solanine) was supposed to be no more than 20mg/100 g of potatoes. So that’s a total of 60mg in a 300 g potato, meaning that you can likely safely consume even green potatoes. Not that you’d want to… they are bitter. But peeling will eliminate the problem, both the flavor and the solanine.
              Citations: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2621.1974.tb07312.x

            5. Species matters, too– I know there are types that can’t be brought into the US because they’ve got too high of levels.

            6. Right. I suspect you could probably acquire some, but not for commercial production. And why would you want them?

  7. Draven Avatar

    I wish my backpack that had my little pocket guide to edible plants hadnt been stolen

    1. Do you want one? I have a few here. I used to collect the things.

      1. Draven Avatar

        i don’t need it as much now. IT was a little wire spiral bound pocket one with slightly laminated pages so you could get it wet without it disintegrating.

        1. Oh, those are nice.

          1. I used to have a few of the ones from Waterford Press, but gave them away when I got too creaky to do much camping. I think the first one was for edible mushroom identification, when I was in college in New Hampshire. (Although I never used it to actually get mushrooms to eat – that is one area where an expert is, I feel, quite necessary.)