Medically Reviewed by Kathleen M. Zelman, RD, LD, MPH on July 14, 2023
Written by WebMD Editorial ContributorWild lettuce (Lactuca virosa) is a weed. It’s sometimes called prickly lettuce, bitter lettuce, tall lettuce, or opium lettuce, and there are many claims of health benefits. But there isn’t strong proof to back them up.
People have used plants as medicine for a long time. Today, they may come in the form of supplements to improve health or to treat health problems. Wild lettuce is one of these plants.
Wild lettuce is a cousin to cultivated lettuce, but it grows as a weed. It’s sometimes called a bitter herb because of its sharp flavor. Wild lettuce also has a noxious or unpleasant smell, and it forms wavy leaves with prickly hairs underneath. Its yellow flowers turn into white fluffy plumes full of seeds that blow with the wind. Wild lettuce is sometimes mistaken for dandelion.
A milky white substance oozes out of the plant when it’s cut and turns brown as it's exposed to air.
This plant self-seeds annually, meaning that it can make and spread seeds on its own. Some people see wild lettuce as a pest and kill it with herbicides. Others use wild lettuce as an herbal supplement.
Wild lettuce has been used throughout history for health problems including:
In the 19th century, the plant’s milky juice was dried and used as a weak alternative to opium with fewer side effects. It was said to be a great pain reliever.
These benefits could be from some of the compounds in the plant including:
Some of these have effects on the body. Lactucarium is a laxative and sedative that lowers gut inflammation and uterine cramping. Sometimes, liquid extracts are used as an enema because of this laxative effect.
Lactucarium and hyoscyamine may be behind some of the sedative effects and pain relief.
Today, you can buy many different forms of wild lettuce including:
There is some research on wild lettuce’s effects in animals. In mice studies, wild lettuce and its compounds were used as a pain reliever and found to work as well as ibuprofen.
These compounds are also found in other plants that lower inflammation and may help with pain relief.
Bitter herbs are sometimes also used to improve digestion. Dandelion is often used for this purpose, and some people accidentally pick wild lettuce instead. Some of the compounds in wild lettuce might also help lower irritation in the gut.
But there is very little evidence of wild lettuce's benefits or risks. There is no proof that it can relieve pain or help digestion. In fact, it might actually cause more digestion problems.
Wild lettuce can be toxic, even in moderate amounts. Some people use liquid extracts in very unsafe ways, which can lead to serious health problems.
Eating raw wild lettuce may have side effects. These symptoms seem to happen based on the amount eaten and can include:
There isn't enough research on supplement forms to fully know the side effects of wild lettuce. Because of its sedative effect, it might interact with sedative medications, which could be unsafe.
If you forage for wild plants, be sure you know how to identify anything before eating it, and avoid eating any unknown plants and herbs.
Talk to your doctor before trying a wild lettuce or any supplement.
Other ways to relieve pain could be safer than an herbal supplement with unknown benefits or side effects. You can:
If you have long-term pain, make sure you talk to your doctor about the best way to manage it.
