Alfalfa

Medicago sativa L.

Sources

17 listed

Best forUsed as a leaf tea, powder or tablet, and as a sprout in the kitchen. The form you choose also determines which safety cautions apply.

Clinical evidence

Traditional

Real World Significance

28Regional historical significance

Breadth 25 Depth 49 Density 13 Convergence 13 Continuity 45

SafetyUse with cautionAlfalfa requires caution. Seeds, sprouts and high-dose supplements should be avoided in lupus and other autoimmune disease. LactMed advises against alfalfa during warfarin treatment. Raw or lightly cooked sprouts carry an infection risk, particularly for vulnerable groups.

Tradition

Folk medicine

Common preparations

Tea infusionTeaPowderTabletExtract

In short

Summary of findings for quick reference

From horse fodder to a tonic: alfalfa has a long history in farming and herbal medicine. Pliny described its cultivation in the first century. Laufer records its importance in Persian horse husbandry and later Persian pharmacology. Ellingwood’s 1919 materia medica documents the North American use of the leaf as a tonic.

Leaf tea, leaf powder, seeds and sprouts are different preparations. Clinical research on seeds is small. In 1987 fifteen patients received forty grams of heat-prepared seeds three times daily for eight weeks. Lower total and LDL cholesterol was reported for the eleven participants with type II hyperlipoproteinaemia. An earlier study involved three volunteers for three weeks. Both studies were uncontrolled and offer little guidance about ordinary leaf tea.

The main cautions concern lupus and other autoimmune disease, warfarin and raw sprouts. Seeds, sprouts and high-dose supplements should be avoided in autoimmune disease. LactMed advises against alfalfa during warfarin treatment because of its vitamin K content. Children, older adults, pregnant women and people with weakened immune systems should avoid raw or lightly cooked sprouts. Concentrated forms also require caution during pregnancy and breastfeeding. Sweet clover is a different plant whose mouldy fodder can form the dangerous anticoagulant dicoumarol.

Clinical evidence ↔ Historical significance

We display two separate evidence categories: clinical evidence from modern trials and historical significance from documented healing tradition. Both are valuable, but they answer different questions.

In every encyclopedia entry we evaluate two distinct categories of evidence. Clinical evidence as used in trials meets a narrower but scientifically essential bar. At the same time, the hundreds of thousands of plant species worldwide have only partially been captured and tested in modern studies.

Alongside the trial picture our researchers compile a comprehensive overview of where and since when a plant has been used across different traditions of natural medicine. When a plant has been used as a medicinal plant in many cultures across many generations, that historical significance deserves to be visible too.

Our position: a truly informative overview emerges only when both categories sit side by side. We communicate transparently what counts as what.

Overview

Alfalfa, Medicago sativa, is a perennial forage crop in the legume family, also known as lucerne. It is grown worldwide to feed livestock. For human use, the leaf and seed need to be distinguished. The dried leaf is made into tea and is also available as powder and tablets. The seeds produce the familiar sprouts. These forms differ in both use and safety.

Its history runs from Persian horse husbandry to North American herbal medicine. Ancient sources mainly describe forage cultivation, while later texts also record medicinal uses. Human research includes small uncontrolled studies of seeds. Particular care is needed with seeds, sprouts and high-dose supplements in lupus or other autoimmune disease, with alfalfa during warfarin treatment, and with raw sprouts for vulnerable groups.

History

The oldest sources discussed here present alfalfa chiefly as a forage crop. In 1919 Laufer traced its Iranian cultivation history and the name aspō-asti to horse fodder. The Arabic word alfalfa entered modern usage through Spanish. In Book XVIII, chapter 43 of his Natural History, Pliny writes that it reached Greece from Media during the wars with Darius. He gives a detailed account of cultivation. The Persian connection is well documented, while the precise date of domestication remains uncertain.

Human use has several historical layers. Laufer also names Abū Manṣūr’s Persian work on pharmacology as a source for alfalfa. He reports that Spanish colonists brought the plant to Mexico and South America in the sixteenth century. In North America, Ellingwood’s 1919 materia medica records a later tonic tradition. His account includes observations by Ben A. Bradley of Ohio in ten men and five women. Reports about appetite, digestion and debility show how physicians used alfalfa at the time. They are historical observations.

Mechanism

Alfalfa contains saponins and oestrogen-like plant compounds, including coumestrol and isoflavones such as genistein and daidzein. Vitamin K matters for its interaction with certain anticoagulants. Nutrient composition depends on the plant part and processing. Analyses of a leaf protein concentrate therefore cannot be applied to the finished tea. Saponins have been investigated for cholesterol binding in the laboratory and effects on cholesterol absorption in animal models.

L-canavanine resembles the amino acid arginine and occurs mainly in seeds and sprouts. In Malinow’s 1982 study, macaques developed blood and antibody changes resembling lupus after eating alfalfa sprouts. L-canavanine reactivated a previously induced syndrome. In 1985 Alcocer-Varela and colleagues found changes in immune regulation in human cells in the laboratory. Together with reports of lupus flares, these findings support caution in autoimmune disease. Lower levels in mature leaves do not remove other warnings, including the warfarin interaction.

A seed study was published in 1987. Mölgaard and colleagues studied fifteen patients, eight with type IIA, three with type IIB and four with type IV hyperlipoproteinaemia. They received forty grams of heat-prepared alfalfa seeds three times daily at meals for eight weeks, with an otherwise unchanged diet. In the eleven type II patients, median total cholesterol fell by 17 %, LDL cholesterol by 18 % and apolipoprotein B by 34 %. The changes were statistically significant. Lipoprotein concentrations returned to pretreatment levels after the seeds were stopped. There was no control group.

In 1980 Malinow and colleagues had already reported lower plasma cholesterol in three volunteers who ate alfalfa seeds for three weeks. The study also included rats in which intestinal cholesterol absorption was examined. These small studies provide no reliable treatment recommendation for leaf tea or sprouts. Phytoestrogens mainly provide a mechanistic basis for interest in menopausal use. The lupus warning rests on animal experiments, laboratory findings and human case reports, and serves a different purpose from evidence of efficacy.

Evidence

4 Outcomes evaluated. Sorted by grade.

Outcome	Class	Grade	Effect	Studies
Traditional use as a tonic (leaf)General adult users of the leaf tea, powder or tablet	Traditional	I	Traditional nutritive use
Blood cholesterol and LDL (heat-treated seed, type II hyperlipoproteinaemia)Fifteen patients with hyperlipoproteinaemia in 1987, eleven with type II. Three volunteers in 1980.	Emerging	I	Two small uncontrolled studies	2 studies
Interest in menopausal use (phytoestrogens)Mechanistic context from oestrogen-like plant compounds	Emerging	I	Preclinical and theoretical only
Lupus-like syndrome and autoimmune flares (seed and sprout, L-canavanine)People with or at risk of systemic lupus erythematosus. Additional evidence comes from a primate model.	Emerging	F	Evidence of harm in autoimmune disease

Key studies

The studies that matter.

1987 · 15 participants
Fifteen patients received forty grams of heat-prepared alfalfa seeds three times daily for eight weeks. The eleven type II patients had statistically significant reductions of 17 % in total cholesterol, 18 % in LDL and 34 % in apolipoprotein B. Levels returned after the seeds were stopped. The small uncontrolled study provides no general recommendation for leaf tea or sprouts.
Mölgaard J, von Schenck H, Olsson AG. Mölgaard J, von Schenck H, Olsson AG. Alfalfa seeds lower low density lipoprotein cholesterol and apolipoprotein B concentrations in patients with type II hyperlipoproteinemia. Atherosclerosis 1987, 65, 173 to 179. doi:10.1016/0021-9150(87)90019-0
1980 · 3 participants
Plasma cholesterol was lower in three volunteers after three weeks eating alfalfa seeds. The paper also studied cholesterol absorption in rats. This very small uncontrolled observation is an early research finding and offers no basis for a reliable treatment recommendation.
Malinow MR, McLaughlin P, Stafford C. Malinow MR, McLaughlin P, Stafford C. Alfalfa seeds: effects on cholesterol metabolism. Experientia 1980, 36, 562 to 564. doi:10.1007/BF01965801
Animal study · 1982
Macaques developed blood and antibody changes resembling systemic lupus after eating alfalfa sprouts. L-canavanine reactivated a previously induced syndrome. This animal experiment contributes to the autoimmune warning alongside human reports.
Malinow MR, Bardana EJ Jr, Pirofsky B, Craig S, McLaughlin P. Malinow MR, Bardana EJ Jr, Pirofsky B, Craig S, McLaughlin P. Systemic lupus erythematosus-like syndrome in monkeys fed alfalfa sprouts: role of a nonprotein amino acid. Science 1982, 216, 415 to 417. doi:10.1126/science.7071589
1919
Ellingwood’s 1919 text records Ben A. Bradley’s observations in ten men and five women described as initially healthy. They took alfalfa for periods ranging from ten days to two months, with accounts including appetite, digestion and weight. The text documents the tonic tradition at that time. It records medical observations and is not a controlled clinical study.
Finley Ellingwood. Ellingwood F. The American Materia Medica, Therapeutics and Pharmacognosy. Medicago sativa entry. 1919. Source

Usage

Forms and preparation

Dried alfalfa leaf is used as an infusion. Prepare a product intended for tea with freshly boiled water according to its pack instructions. Its historical description as a tonic gives no measure of the vitamin K or other nutrients in a cup. Powders and tablets are separate preparations whose composition can differ from tea. Alfalfa sprouts are grown from seeds. Keep purchased sprouts refrigerated and separate from raw meat and utensils used for it. Washing does not reliably remove bacteria, so children, older adults, pregnant women and people with weakened immune systems should avoid raw or lightly cooked sprouts. Cook sprouts until steaming hot throughout to reduce the infection risk. This does not remove the autoimmune warning for seeds and sprouts.

Dosage

The studies discussed here provide no clinically tested general dose for alfalfa leaf tea. The 1987 seed study used forty grams of heat-prepared seeds three times daily for eight weeks. This was a patient study dose and is not a recommendation for self-treatment. Follow the product instructions and discuss regular use with your clinician, particularly if you take medicines. Avoid seeds, sprouts and high-dose supplements in autoimmune disease, and LactMed advises against alfalfa during warfarin treatment.

Special populations

Avoid alfalfa seeds, sprouts and high-dose supplements if you have systemic lupus erythematosus or another autoimmune disease. LactMed advises against alfalfa during warfarin treatment, and changes to existing use should be discussed with your clinician. Concentrated and supplemental forms should be avoided during pregnancy and breastfeeding. Children, older adults, pregnant women and people with weakened immune systems should also avoid raw or lightly cooked sprouts.

Safety

Safety profile

Safety depends on the plant part, preparation and personal circumstances. Seeds and sprouts carry the L-canavanine warning, while raw sprouts add an infection risk. Lower canavanine levels in mature leaves do not remove warnings for leaf tea or supplements, including during warfarin treatment. Tolerability as a food does not replace assessment of a concentrated preparation. Avoid alfalfa seeds, sprouts and high-dose supplements in systemic lupus erythematosus or other autoimmune disease. LactMed advises against alfalfa during warfarin treatment because of its vitamin K content, and changes to existing use should be discussed with your clinician. Children, older adults, pregnant women and people with weakened immune systems should avoid raw or lightly cooked sprouts. For others, thorough cooking reduces the infection risk. Hormone-sensitive conditions, pregnancy and breastfeeding are further reasons for caution with concentrated forms. Stop use and seek advice if unexpected symptoms occur.

Drug interactions

Vitamin K can alter the effect of vitamin K antagonists such as warfarin. LactMed therefore advises against alfalfa during warfarin treatment. Existing use should not be changed abruptly without clinical advice, and vitamin K intake should remain consistent. Oestrogen-like plant compounds warrant caution with hormonal medicines and hormone-sensitive conditions. Laboratory findings on L-canavanine also provide a theoretical reason for caution with immunosuppressants. This is not a clinically tested drug interaction, and the warning against seeds and sprouts in autoimmune disease still applies.

Contraindications

If you have systemic lupus erythematosus or another autoimmune disease, avoid alfalfa seeds, sprouts and high-dose supplements because of their association with lupus-like effects. Discuss other alfalfa preparations with your doctor. LactMed advises against alfalfa during warfarin treatment. Do not start tea or supplements on your own. Discuss changes to existing use with your doctor and maintain consistent vitamin K intake. Discuss concentrated forms with your doctor if you have a hormone-sensitive condition because of their oestrogen-like compounds. Memorial Sloan Kettering also advises against alfalfa in gout. Avoid concentrated and supplemental forms during pregnancy and breastfeeding. Pregnant women should also avoid raw or lightly cooked sprouts. Children, older adults and people with weakened immune systems should avoid raw or lightly cooked sprouts because of the infection risk.

Side effects

Reports following alfalfa supplements include intestinal gas, abdominal discomfort, more frequent stools and diarrhoea. The literature also describes lupus flares associated with alfalfa. Raw sprouts can cause foodborne illness through Salmonella or E. coli. Allergic reactions are possible. For a lucerne leaf protein concentrate, EFSA could not exclude cross-reactions in people with peanut allergy. Stop use and seek medical advice if you develop joint pain, rash, fatigue or other unexplained symptoms.

Look-alikes

Botany

Family

Fabaceae

Native regions

Native to the highlands of ancient Persia, the Caucasus and Central Asia (Iran, Anatolia, Afghanistan), Naturalised and cultivated worldwide as a forage crop, Major modern cultivation in the Americas, Europe and Australia

Harvest window

Aerial parts cut before or at early flowering for the leaf. Seed harvested at maturity. Sprouts grown from seed year round.

Habitat

Alfalfa grows in sunny, open places with well-drained soil. Kew gives its native range as the Mediterranean to Central Asia and Iran. It is now cultivated far beyond that range as a forage crop. Its deep taproot helps it withstand dry periods. Alfalfa lives with nitrogen-fixing bacteria at its roots. The University of Minnesota recommends a soil pH of at least 6.5 for good yields, which also favours these bacteria. This recommendation concerns growing alfalfa as a perennial forage crop.

Identification & foraging

The upright, branched stems carry leaves with three leaflets, toothed towards their tips. Small pea-like flowers grow in racemes and are usually violet to pale lavender. The pods are curved or spirally coiled. Kew describes stems reaching sixty centimetres in its species profile. Growth and flower colour vary between forms, so colour alone is insufficient for identification.

Similar plants and look-alikes

Toxic

Sweet clover (Melilotus officinalis, Melilotus albus)

Sweet clover, Melilotus officinalis or Melilotus albus, is another legume with yellow or white flowers in long racemes. Identifying alfalfa therefore also requires its three-part leaves and curved or coiled pods. Mouldy sweet clover can contain dicoumarol, a potent anticoagulant known in veterinary medicine to cause dangerous and sometimes fatal bleeding in cattle. Do not confuse the plants.

Unpleasant

Alfalfa leaf, seeds and sprouts

These are different parts of the same plant. Leaf tea differs from seeds or sprouts. L-canavanine occurs mainly in seeds and sprouts, and its content decreases as the plant matures. A safe tea dose cannot be inferred from the lower content in leaves. Check which plant part a product contains. Raw sprouts also carry a risk of foodborne infection.

FAQs

Which part of alfalfa is used, the leaf or the seed?

The leaf is used for tea and some supplements. The familiar sprouts grow from seeds. Read the plant-part information on the pack, as seeds and sprouts are particularly relevant to the L-canavanine warning. Raw sprouts also carry an infection risk.

Why should people with lupus or autoimmune disease avoid alfalfa?

Seeds and sprouts contain L-canavanine. Alfalfa caused a lupus-like syndrome in a primate model, and human reports describe lupus flares after alfalfa supplements. Laboratory work in human immune cells supports the association. If you have lupus or another autoimmune disease, avoid alfalfa seeds, sprouts and high-dose supplements and discuss other forms with your doctor.

Does alfalfa interact with blood thinners?

Yes, particularly with vitamin K antagonists such as warfarin. LactMed advises against alfalfa if you take warfarin because of its vitamin K content. Do not start alfalfa tea or a supplement on your own. Discuss changes or stopping an existing preparation with your clinician as well. In general, vitamin K intake should remain consistent during treatment with these anticoagulants.

Are raw alfalfa sprouts safe to eat?

Raw or lightly cooked sprouts can contain harmful bacteria, including Salmonella and E. coli. Clean production or washing does not reliably make them free of pathogens. Children, older adults, pregnant women and people with weakened immune systems should avoid them. Cook sprouts until steaming hot throughout to reduce the infection risk.

Is alfalfa approved by a European regulator for any health use?

Permission to market a food does not confirm a health effect. In 2009 the EU authorised a specifically described lucerne leaf protein extract as a novel ingredient for food supplements. The manufacturer’s recommended daily portion could contain no more than 10 g of this extract. That decision concerns the specified concentrate under those conditions. It is neither evidence of efficacy for leaf tea nor a recommendation for seeds or sprouts. Traditional uses and the small seed studies provide no general treatment recommendation.

Can I take alfalfa in pregnancy or while breastfeeding?

Avoid concentrated or supplemental alfalfa during pregnancy and breastfeeding. Its hormone-like activity warrants caution, and LactMed reports no reliable safety data for nursing mothers or infants. Historical use to increase milk supply is not evidence of efficacy. During pregnancy also avoid raw or lightly cooked sprouts because of the infection risk. Discuss use beyond ordinary food amounts with your doctor or midwife.

References

17 sources.

Mölgaard J, von Schenck H, Olsson AG. Mölgaard J, von Schenck H, Olsson AG. Alfalfa seeds lower low density lipoprotein cholesterol and apolipoprotein B concentrations in patients with type II hyperlipoproteinemia. Atherosclerosis 1987, 65, 173 to 179.. 1987. doi:10.1016/0021-9150(87)90019-0
Malinow MR, McLaughlin P, Stafford C. Malinow MR, McLaughlin P, Stafford C. Alfalfa seeds: effects on cholesterol metabolism. Experientia 1980, 36, 562 to 564.. 1980. doi:10.1007/BF01965801
Malinow MR, Bardana EJ Jr, Pirofsky B, Craig S, McLaughlin P. Malinow MR, Bardana EJ Jr, Pirofsky B, Craig S, McLaughlin P. Systemic lupus erythematosus-like syndrome in monkeys fed alfalfa sprouts: role of a nonprotein amino acid. Science 1982, 216, 415 to 417.. 1982. doi:10.1126/science.7071589
Alcocer-Varela J, Iglesias A, Llorente L, Alarcón-Segovia D. Alcocer-Varela J, Iglesias A, Llorente L, Alarcón-Segovia D. Effects of L-canavanine on T cells may explain the induction of systemic lupus erythematosus by alfalfa. Arthritis Rheum 1985, 28, 52 to 57.. 1985. doi:10.1002/art.1780280109
Finley Ellingwood. Ellingwood F. The American Materia Medica, Therapeutics and Pharmacognosy. Medicago sativa entry. 1919.. 1919. Source
Berthold Laufer. Laufer B. Sino-Iranica. Alfalfa chapter, pages 208 to 210. Field Museum of Natural History, 1919.. 1919. Source
Pliny the Elder, translated by John Bostock and H. T. Riley. Pliny the Elder. Natural History, Book XVIII, chapter 43. Bostock and Riley English translation.. 1855. Source
National Library of Medicine. National Library of Medicine. Alfalfa. Drugs and Lactation Database, updated 21 June 2021.. 2021. Source
NIH Office of Dietary Supplements. Vitamin K, Health Professional Fact Sheet. Source
US Food and Drug Administration. US Food and Drug Administration. Selecting and Serving Produce Safely.. 2026. Source
Centers for Disease Control and Prevention. Centers for Disease Control and Prevention. Safer food choices.. Source
Memorial Sloan Kettering Cancer Center. Memorial Sloan Kettering Cancer Center. Alfalfa, About Herbs.. Source
EFSA Panel on Dietetic Products, Nutrition and Allergies. EFSA NDA Panel. Opinion on the safety of Alfalfa protein concentrate as food. EFSA Journal 2009, 997, 1 to 19.. 2009. doi:10.2903/j.efsa.2009.997
European Commission. European Commission. Decision 2009/826/EC authorising a leaf extract from lucerne as a novel food ingredient. 13 October 2009.. 2009. Source
Royal Botanic Gardens, Kew. Royal Botanic Gardens, Kew. Medicago sativa L. Plants of the World Online, species profile and descriptions.. Source
Merck Veterinary Manual. Merck Veterinary Manual. Moldy sweet clover poisoning in animals.. Source
University of Minnesota Extension. University of Minnesota Extension. Fertilizing alfalfa in Minnesota.. Source

Legal notice: The depiction of historical significance and traditional use is context within our encyclopedia and not a health claim for any product, not a treatment promise, and not a substitute for medical advice. What may be stated on product labels, product pages, or in advertising is governed by the applicable legal requirements.