I have previously written of the herbal extract known as lactucarium (1) produced from the wild herb Lactuca virosa. This plant, also known as wild lettuce is an edible plant whilst still young and tender. As it ages it becomes too prickly and bitter to eat. Much like other plants of its ilk (dandelion, cats ear, sowthistle) it produces a sticky white sap (or latex). It is this sap which is processed to create a herbal medicine. It is this medicine that gives the plant one of its other names, wild opium.
- See Post Dandelion? Identifying Wild Plants.
The white sap of this plant can be harvested and dried into a brown substance known as lactucarium. Concentrations of lactucarium are low in young plants and most concentrated when the plant comes into flower. If procured later in the season the latex “may be thicker but it contains less of the bitter matter on which its virtues probably depend” (Anilakumar etal 2017) (1). In 1917, the Servall Company asserted that wild lettuce was “highly esteemed to quiet coughing and allay nervous irritation, a good safe remedy to produce sleep, to be used when opium and other narcotics are objectionable” (Besharat 2009).
- for the medicinal uses of lactucarium see Post Dandelion? Identifying Wild Plants.
This plant and its extract were listed in the United States Pharmacopoeia at the time. This was essentially an approved list (1) of pharmaceutical drugs. It was taken seriously then so there is no reason not to take it seriously now. Although it can compare in no way, medicinally speaking, to that of opium (2) it was an important medicine for those who could not tolerate opium well. Side effects for an overdose of lactucarium are essentially the same as opium. Some of its side effects and toxicity resulting from overdose include mydriasis (3) and photophobia (4), dizziness, diaphoresis (5), auditory hallucination, and cardiovascular and respiratory difficulties caused by dysrhythmia (6) (Zargari 1990).
- usually approved by the government or some other professional body
- another herbal extract, of the Papaver somniferum poppy. Opium is the source material for both heroin and codeine.
- dilation (widening) of the pupil of the eye.
- extreme sensitivity to light
- excessive sweating
- abnormal heart rhythm

The image above shows a mature poppy seed head which has been carefully cut so the latex can be collected.

I “found” this plant today by the laundry door. It has been allowed to grow this size as it has missed my landlord mandated weeding as we don’t really use this door. This plant has a somewhat unusual structure regarding its stem height and leaf arrangement due to its somewhat inhospitable growing environment.

Differentiation in leaf shape. From the ground up. These leaves are not suitable to eat. You could, if in complete starvation situations, simmer up a potful of these to eat. It wouldn’t be pleasant……In fact, ignore what I just said. Don’t eat these.

Next level up. Leaf shape is becoming a little misshapen, even “spear” like. Leaves are still too fibrous to be palatable.

As we climb even higher the prickles on the plant are becoming more noticeable. These prickles are still fairly soft. Even on the most mature, somewhat dried out plants these prickles would only present a minor problem, even for the most sensitive skin; small children for instance.

We are now at the top of the plant. These leaves, although somewhat ferocious looking are perfectly edible. They are soft and once the prickles are removed can be eaten raw. This plant is not far from flowering, after which it becomes more bitter to eat. It is however perfectly placed for me to attempt making some lactcarium.


The United States Pharmacopoeia gave instructions for the manufacture of lactucarium,
“It is obtained by cutting off the upper portion of the stem, thus allowing the latex to exude, so that it can be transferred to a small cup. After twenty-four hours a thin slice is removed from the cut surface and the operation repeated. The collected latex soon solidifies, and is then removed from the cup, cut into pieces, and dried, gradually acquiring a dull brownish colour during the process.“

I will not be cutting the tops off (as I only have 2 plants to work with) but I have scored the stalk in various places to (hopefully) around 1mm in depth with a very sharp blade.

I will collect this latex over a period of time (I know not how long, I’ve never done this before and I’m running on minimal instruction) and see how much resin I can collect. Further instruction goes on to say…… The drug occurs in hard, opaque, irregular pieces, often curved on one side. They are dull brown in colour, but the interior, in recent pieces, may still be whitish and soft. The odour is characteristic, recalling that of opium; taste, bitter.” The dried latex may be dissolved in alcohol or smoked as pure resin or in a smoking blend together with herbs such as Cannabis or thorn apple (Miller 1985)(1).
- I DO NOT recommend the ingestion of thorn apple (Datura species). This is a powerful shamanic plant said to contain a capricious (and possibly malevolent) spirit. Tread with caution if you enter this door.
A modern method used to take wild lettuce is to dry the leaves and roots and smoke them. Yet another technique is to heat, not boil, the leaves in water for at least eight hours and then remove the liquid. The lactucarine leaches into the water solution. Once the water has evaporated, the result is a black gum that is often smoked. This resin must be sealed in plastic to prevent it from drying out. An effective dose is generally about one ounce of dried wild lettuce leaves or approximately one-half gram of the extract per person.
Lactuca was still listed in the British Herbal Pharmacopoeia as late as 1983 (that’s how old my copy is anyway) as a herbal medicine. It is recommended that the powdered, dried leaves be used. The powder can be encapsulated or infused as a tea. A 1:1 (1) tincture of 25% alcohol was recommended. No mention of the sap was made in any medicinal way. It stated that “The fresh plant when cut exudes a latex known as lactucarium containing lactucone (2), lactucin (3) and lactucic acid (4).
- each ml contains 1g (or 1000mg) of herb. A 1:2 indicates that each 2ml of liquid contains 1000mg of herb (so only 1/2 the strength of a 1:1). A 2:1 indicates that there are 2000mg of herb in 1ml of liquid (so double the strength of a 1:1)
- A white, crystalline, tasteless substance, found in the milky sap of species of Lactuca, and constituting an essential ingredient of lactucarium.
- a bitter substance that forms a white crystalline solid and belongs to the group of sesquiterpene lactones. It is found in some varieties of lettuce and is an ingredient of lactucarium. It has been shown to have analgesic and sedative properties. It has also shown some antimalarial effects. It is also found in dandelion coffee.
- Any of various acids derived from the juice of Lactuca virosa. A light-yellow crystalline compound, C40H58O11, formed by the action of dilute sulphuric acid on lactcuarium.
Right then. Off I go.
References
- Anilakumar, Kandangath Raghavan, S. N. Harsha, Mallesha and Rakesh Kumar Sharma. “Lettuce: a promising leafy vegetable with functional properties.” (2017).
- Besharat, S., Besharat, M., & Jabbari, A. (2009). Wild lettuce (Lactuca virosa) toxicity. BMJ case reports, 2009, bcr06.2008.0134. https://doi.org/10.1136/bcr.06.2008.0134
- Funke, I. & Siems, W.-E & Schenk, Regina & Melzig, Matthias. (2002). Lactuca virosa L. and Lactucarium: A molecular-pharmacological essay of analgesic potency. Zeitschrift fur Phytotherapie. 23. 40-45.
- Miller, R.A. The Magical and Ritual Use of Aphrodisiacs. New York: Destiny Books, 1985.
- Zargari, A “Medicinal Plants (in Persian),” Tehran University Press, Tehran, 1990