How does it feel?
Wild lettuce is an acrid, bitter cooling medicine that offers a grounding and relaxing effect upon the mind and body. Hypnotic and sedative herbs like wild lettuce can support the health status of all body systems as they allow for deep relaxation and relief from nervous tension.
Wild lettuce lives up to its common name ‘bitter lettuce’ with a sharp bitterness that sits on the sides of the tongue. There is also a notable mild earthy taste.
What can I use it for?
Whilst wild lettuce is a commonly foraged salad green in Europe and some parts of UK it is not so much of an entry level plant for home herbalism. It is often used by herbalists for its antispasmodic and sedative actions. However, there are reports of people experiencing side effects from its use. This was from having very high doses, which highlights why it is important to respect and reference traditional use and knowledge. You can learn more about this in the safety section of this article and we have listed doses here.
As a foraged edible, it has a potent bitter flavour so is often recommended by foragers to be used at a lower ratio as the flavour may be overpowering for some. Most would say wild lettuce has a late summer harvest. Or is harvested late summer?
In medicinal doses, wild lettuce may be used to help with short-term sleep disturbances. It is a sedative and hypnotic so it is sometimes used for insomnia and to help one relax into deep and fulfilling sleep.
As an antispasmodic agent, wild lettuce is also used to support with persistent coughs that follow on from acute viral infections such as a cold. The best application of wild lettuce for this purpose is for the dryer, spasmodic type of coughs. Herbalists don’t often recommend suppressing the cough reflex for productive coughs due to the understanding of its physiological purpose to clear the lungs. See ‘What practitioners say’ for more information on this and how wild lettuce is used by herbalists.
It is best to seek medical advice if a cough persists for longer than 3- 4 weeks as persistent coughs can sometimes indicate a more serious health condition.
Into the heart of wild lettuce
In the understanding of western herbalism wild lettuce is moderately cooling and slightly moist. Put simply, moist and cooling herbs are used to treat hot, inflammatory conditions that have dry tendencies. These are preferred over dry cooling (e.g. raspberry leaves, plantain), or dry warming (nettle, rosemary) herbs for example; those that have more astringency which may be counterproductive in the treatment of these type of conditions (2).
In traditional Chinese medicine (TCM) plants with an acrid flavour are used to treat wind and chill. In TCM these are conditions that are equivalent to constriction. The appropriate energetic manifestation of such illness may be seen as tension, muscle spasms and chills that are not easily calmed. The mind and nerves are deeply affected by this tissue state and symptoms of unease in the mind may include anxiety, panic and nervousness. Such tissue state in the TCM understanding is described as an excess of wind and chill (2).
The energetic picture of wild lettuce as described above is well reflected in its traditional and modern applications in treatment of tensions. Wild lettuce can be applied for tensions in the mind (nervousness, hyperactivity and insomnia) and in the body (spasmodic conditions in the musculoskeletal and respiratory system). Its effects are subtle, and it is often combined with other grounding herbs such as skullcap and valerian.
Traditional uses
In the mid 1700’s wild lettuce was well known as a painkiller and sedative in European folk tradition.
The plant-protecting latex was traditionally extracted into a black resin leading to it being called ‘opium lettuce’. Herbalists called this dried latex ‘lactucarium’ which is easy to store and administer.
Later, in the 19th century, the juice or ‘lactucarium’, was more widely used for the same effects. There was also reference for use in kidney disorders, for ameliorating painful uterine contractions linked to menstruation, and for generalised oedema and jaundice, likely due to its diuretic and detoxifying effects.
Wild lettuce was at the heart of some very early research due to its opiate content. Mrs Greive states that an early practitioner in research of plant medicines, Dr Collins reported that ‘twenty-three out of twenty-four cases of dropsy were cured by taking doses of 18 grains to 3 drachms of extract in twenty-four hours’ (1).
Traditional actions
Herbal actions describe therapeutic changes that occur in the body in response to taking a herb. These actions are used to express how a herb physiologically influences cells, tissues, organs or systems. Clinical observations are traditionally what have defined these actions: an increase in urine output, diuretic; improved wound healing, vulnerary; or a reduction in fever, antipyretic. These descriptors too have become a means to group herbs by their effects on the body — herbs with a nervine action have become the nervines, herbs with a bitter action are the bitters. Recognising herbs as members of these groups provides a preliminary familiarity with their mechanisms from which to then develop an understanding of their affinities and nuance and discern their clinical significance.
Chinese actions
Traditional energetic actions
Herbal energetics are the descriptions Herbalists have given to plants, mushrooms, lichens, foods, and some minerals based on the direct experience of how they taste, feel, and work in the body. All traditional health systems use these principles to explain how the environment we live in and absorb, impacts our health. Find out more about traditional energetic actions in our article “An introduction to herbal energetics“.
What practitioners say
Nervous system
As a sedative and hypnotic, wild lettuce is primarily used in the treatment of acute sleep disturbances and insomnia. This may be applied to help moderate tensions and anxiety syndromes in the short term. Sedative herbs like wild lettuce are also indicated to support those weaning off conventional sedative medications (5).
Another potential indication for wild lettuce is hyperactivity and over-excitability. The sedative effects of this herb will also be supportive for those suffering from acute anxiety and restlessness.
A herbalist will use sedatives only intermittently or for short periods. For example, they may be applied to support patients during acute phases of insomnia and anxiety. This is because they work to treat the symptom of a problem rather than the root cause and for long-term healing to happen one would need more than just a sedative.
For chronic conditions, a medical herbalist would make a formulation which would aim to resolve the issue on a deeper level. A herbalist understands that the root cause of disease will often be unique to the patient and will require a personalised approach to address the problem. Whilst home herbalism is a powerful and useful skill, consulting a learned herbalist will always be best for chronic and complex conditions.
Musculoskeletal system
Wild lettuce may be used where there are tensions or spasmodic states throughout the body. It is specifically antispasmodic and anti-rheumatic, and so it may therefore be applied to work upon smooth and striated muscle tensions. This is mostly taken as an internal medicine to work on the tissue state systemically rather than as a topical preparation, although historically it was applied in both internal and external forms (3).
Respiratory system
Wild lettuce’s excellent antispasmodic properties may be applied in the holistic treatment of spasmodic coughs. It has long been used as an anti-tussive (an agent that reduces coughing).
This action may be used in the circumstances of a nervous cough or by a practitioner who may prescribe this plant where relentless coughing is caused by a tumour for example. Another typical indication for antitussives would be a non-productive, severe or persistent cough that is stubborn against treatment with expectorants (5).
Many herbalists understand that reducing the cough reflex may in fact be counterproductive for example where irritants or mucous congestion is the cause. This is because the cough reflex allows for the mobilisation and expulsion of congestion and therefore relief. Herbalists understand that reducing this reflex may reduce the necessary cleansing of the lungs (5).
Reproductive system
Wild lettuce is an anaphrodisiac, which means that it reduces sexual desire. It may also be applied for its antispasmodic properties to assist in menstrual cramps.
Research
There is little available modern research on wild lettuce, particularly clinical trials and human studies. Animal studies, particularly those using isolated compounds are not only unethical but they are also problematic due to their lacking in context against the holistic understanding of human pathophysiology. This type of research does not reflect the complexities of the patient’s pathophysiology, nor the plant phytochemically.
Animal studies are not condoned by herbal reality, however for the purpose of including research from which some understanding of therapeutic actions can be confirmed, animal studies have been included herein.
Analgesic and sedative
A study was carried out in which three active compounds, found in wild lettuce – lactucin and its derivatives lactucopicrin and 11β,13-dihydrolactucin were investigated for their sedative and analgesic effects, using in vivo methods.
The compounds showed similar analgesic effects at doses of 15 and 30 mg in the hot plate test in a similar capacity to ibuprofen. Of the three compounds, lactucopicrin appeared to be the most potent in analgesic outcomes. Lactucin and lactucopicrin, but not 11β,13-dihydrolactucin, also showed positive sedative properties (8).
Anti-inflammatory
A study was carried out to evaluate the anti-inflammatory effects of the aqueous extracts of asthma plant (Euphorbia hirta) and wild lettuce. The study combined data from in vivo and in vitro methods. The former was to induce Albumin and histamine inflammation in mice as well as xylene induced ear oedema.
A number of variants in combination of the two plants were given, all showing a significant reduction of paw inflammation in mice compared to the control in the albumin and histamine induced inflammatory test. The study concludes a positive anti-inflammatory potential for the plant extracts of asthma plant and wild lettuce both in vivo and in vitro (7).
Lactucarium
Lactucarium is a diuretic, laxative and sedative agent. It is well-referenced for use as an anti-tussive and to relieve dyspnoea. Due to its antispasmodic effects, it also decreases gastrointestinal inflammation and spasmolysis as well as uterine contractions. It has anticonvulsant and hypnotic effects as well. Additionally, lactucarium contains traces of hyoscyamine, an alkaloid found in henbane and other nightshade plants. This is thought to be the likely explanation for its sedative effects (6).
Did you know?
The latex (or milky sap) of wild lettuce was once sold as ‘lettuce opium’ or lactucarium, as it was called in the official pharmacopoeias of the day. It is said to contain nano-particles of opium, however not in amounts that would qualify it as a major opiate agent. Herbal medicines often contain hundreds of active compounds that work synergistically to create their effect, as is the case with wild lettuce.
Additional information
Botanical description
Wild lettuce is a biennial herb that grows commonly in Europe and some parts of the UK as a weed. It can grow to a maximum height of 6ft. The erect stem, springing from a brown tap-root, is smooth and pale green, sometimes spotted with purple/ reddish patches (be careful with plants that display this feature as it is a feature shared with some highly poisonous plants such as hemlock).
There are a few prickles on the lower part and short horizontal branches above. The numerous, large, radical leaves are from 6 to 18 inches long, entire, obovate/ oblong. The stem leaves are scanty, alternate, and small, clasping the stem with two small lobes.
The heads are numerous and shortly-stalked, the pale-yellow flower being strap-shaped. The whole plant is rich in a milky juice that flows freely from any cut surface. This milky sap was traditionally known as lactucarium and it has a bitter taste and a narcotic odour. When dry, it hardens, turns brown.
Common names
- Wild lettuce
- Bitter lettuce
- Opium lettuce
- Poisonous lettuce
- Tall lettuce
- Great lettuce
- Laitue vireuse
- Rakutu-karyumu-so
Safety
There are reports of side effects for this plant. A paper was published in 2009 describing 8 patients who were admitted to the same hospital who had apparently ingested wild lettuce as fresh herb potentially in large quantities. It was also speculated that the herb had been harvested before the usual time for harvesting. Usually, wild lettuce is harvested in late summer. In this case, it is suggested that harvesting took place in May (6).
The paper suggests that this was a case of overdose. It is important to follow the recommended dosage advice to avoid adverse reactions. The side effects from overdose included mydriasis, photophobia, dizziness, diaphoresis, auditory hallucination, and cardiovascular and respiratory difficulties caused by dysrhythmia (6).
It is important to note the reports are out of context with normal prescribing levels, and the people had a very high dose. Given the compounds in wild lettuce, it is not surprising people had unwanted effects. This highlights the importance of referring to credible herbal texts which highlight how herbalists use the plant, in order to make sure it is used safely. Better yet, see a herbalist.
Wild lettuce should be avoided during pregnancy and lactation.
Interactions
Wild lettuce may enhance the effects of sedative medications. It is best to avoid taking wild lettuce if you are using any medications that may induce sedation.
Contraindications
Wild lettuce should be avoided by those who have a known sensitivity or allergy to plants in the Asteraceae (daisy) family
Preparations
- Tincture
- Lactucarium (a plastic-like solid brown substance made up of the dried latex/milky sap that is exuded from the plant when cut)
- Dried leaf (less often)
- Fresh i.e. mixed into a foraged salad
Dosage
Tincture (1:1 in 25%): Tincture dosage is recommended at between 0.5ml-4ml
Infusion: Infuse 1- 2 teaspoons of dried herb into a mug of boiling water and infuse for up to 15 minutes. Strain and drink up to three times a day.
Dried or raw plant: 0.5-4g a day
Lactucarium: The US pharmacopoeia recommends a dosage of 2ml lactucarium tincture three times a day (4).
Plant parts used
- Whole aerial parts
- Leaf
Constituents
- Sesquiterpene lactones – lactucin
- Coumarins- ci-chorin and aesculin
- Acids
- Alkaloids- hyoscyamine
- Flavanoids- querceti
- Terpenoid bitters
- Resin
- N- methyl- β- phenethylamin (3, 6)
Habitat
The native range of this species is Madeira, Europe and NW. Africa. It grows primarily in the temperate biome. Wild lettuce is widespread across much of central and southern Europe. It can be found locally in the South-east/ East of England. It is seldom found across the rest of the United Kingdom. Wild lettuce grows almost anywhere with good sunlight. It may be found growing between paving slabs, gaps in walls, flower beds and especially freshly disturbed soil around field edges.
Sustainability
The IUCN Red List of Threatened Plants has assessed the population trends of this plant across Europe and pan Africa. It is currently classed as ‘Least concern’ under the red list database. This means that the population of this species is stable and under no specific threat of extinction (9).
Habitat loss and over harvesting from the wild are two of the biggest threats faced by medicinal plant species. There are an increasing number of well-known herbal medicines at risk of extinction. We must therefore ensure that we source our medicines with sustainability in mind.
The herb supplement industry is growing at a rapid rate and until recent years much of the medicinal plant produced in global trade was of unknown origin. There are some very real and urgent issues surrounding sustainability in the herb industry. These include environmental factors that affect the medicinal viability of herbs, the safety of the habitats that they are taken from, as well as the welfare of workers in the trade.
The botanical supply chain efforts for improved visibility (transparency and traceability) into verifiably sustainable production sites around the world is now certificated through the emergence of credible international voluntary sustainability standards (VSS). Read our article on sustainable sourcing of herbs to learn more about what to look for and questions to ask suppliers about sustainability.
Quality control
The milky sap that is produced by this plant which holds much of its medicinal compounds and is not viable as a medicine in powdered form. Most often this plant is made as whole plant or lactucarium tincture. It is only slightly soluble in boiling water, therefore an infusion is also a less viable option for using this plant medicinally (1).
It is recommended to harvest this plant in the second year when it exudes more of the white latex for a more potent medicine.
Herbal Medicines are often extremely safe to take, however it is important to supply herbal medicines from a reputed supplier. Sometimes herbs bought from unreputable sources are contaminated, adulterated or substituted with incorrect plant matter.
Some important markers for quality to look for would be to look for certified organic labelling, ensuring that the correct scientific / botanical name is used and that suppliers can provide information about the source of ingredients used in the product. A supplier should be able to tell you where the herbs have come from. There is more space for contamination and adulteration where the supply chain is unknown.
How to grow
Wild lettuce grows in the wild as a weed in many cooler parts of Europe. It is easy to grow and will spread each season when it goes to seed.
- It is best to sow seeds in early spring or fall, in pots outdoors or directly in beds outdoors. Sprinkle soil on the seed and tamp securely, then keep cool and evenly moist until germination.
- Germination should occur within 10 to 20 days, it can be longer in colder conditions.
- In most cases a spacing of around 30cm between plants should be fine, but you may want to increase that a bit if the soil is rich in nutrients, producing larger leaves.
- The plant needs very little care and will grow happily in well-drained sandy soils in a sunny position.
- The leaves are edible and can be added to a salad (some may disagree because of the bitter flavour). However if it is the milky sap you are growing it for, leave it for the first year and harvest it when it has started to send up its flowering spikes in year two.
References
- botanical.com. (n.d.). A Modern Herbal | Lettuce, Wild. [online] Available at: https://www.botanical.com/botanical/mgmh/l/lettuc17.html [Accessed 7 Dec. 2022].
- M. 2004. The Practice of Traditional Western Herbalism: Basic Organs and Systems. North Atlantic Books,U.S.
- Menzies-Trull, C. (2013). Herbal medicine keys to physiomedicalism including pharmacopoeia. Newcastle: Faculty Of Physiomedical Herbal Medicine (Fphm).
- Hoffman, D. (2003). Medical Herbalism: The Science Principles and Practices Of Herbal Medicine. Hardback (1st Edition). Independently published
- Bone, K. and Mills, S. (2013). Principles and practice of phytotherapy modern herbal medicine. 2nd ed. Edinburgh Churchill Livingstone, Elsevier.
- Besharat, S., Besharat, M. and Jabbari, A. (2009). Wild lettuce (Lactuca virosa) toxicity. Case Reports, 2009(apr23 1), pp.bcr0620080134–bcr0620080134. doi:10.1136/bcr.06.2008.0134.
- Uwaya, D., Okakwu, R. and Omozuwa, O. (2021). In-Vivo and In-Vitro Anti-Inflammatory Activities of the Aqueous Extract of Di-Herbal Formulation (Euphorbia hirta and lactuca virosa). Journal of Applied Sciences and Environmental Management, 24(11), pp.1979–1985. doi:10.4314/jasem.v24i11.19.
- Wesołowska, A., Nikiforuk, A., Michalska, K., Kisiel, W. and Chojnacka-Wójcik, E. (2006). Analgesic and sedative activities of lactucin and some lactucin-like guaianolides in mice. Journal of Ethnopharmacology, 107(2), pp.254–258. doi:10.1016/j.jep.2006.03.003.
- Ouedraogo, L. (2008). IUCN Red List of Threatened Species: Lactuca virosa. [online] IUCN Red List of Threatened Species. Available at: https://www.iucnredlist.org/species/164487/5889689#habitat-ecology [Accessed 8 Dec. 2022].