Alfalfa

What is Alfalfa?

Alfalfa (Medicago sativa) is a deep-rooted legume grown around the world as animal feed. In herbal use, the dried leaf is taken as a tea, a tablet or a liquid extract. The sprouted seeds are eaten raw as a salad food.

People take alfalfa leaf as a nutrient-rich "tonic" (a general pick-me-up), and for high cholesterol, poor appetite and menopause symptoms. It is also sold as a source of vitamin K, calcium and other minerals.

The honest verdict: alfalfa has a long record in Western folk herbalism, but human trial evidence is thin, small and decades old. Traditional use is not proof that something works, and that applies to everything on this page. Alfalfa also carries real safety limits, so please read the safety section before you try it.

How does Alfalfa work?

Nobody has pinned down how alfalfa works in people, and the honest answer is that most of the mechanism talk comes from lab and animal work.

The cholesterol idea is the best developed. Alfalfa contains saponins, soap-like plant compounds that bind to cholesterol and bile in the gut so less of it is absorbed. Animal studies support this; human data is scarce.

Alfalfa also contains coumestrol, a plant compound that acts weakly like oestrogen (a female sex hormone). That is the usual explanation offered for menopause use, but it has not been shown to help hot flushes in a good trial.

What forms does Alfalfa come in?

Dried leaf is the form with the longest traditional record and the mildest safety profile. It is sold loose for tea, in tea bags, and pressed into tablets or capsules.

Liquid extracts and tinctures (herb soaked in alcohol) are also sold. Alfalfa powder and "green food" blends use the dried leaf too, usually mixed with other greens.

Sprouted seeds are a salad vegetable rather than a medicine. Concentrated seed or sprout supplements are the riskiest form, because canavanine is concentrated there. We do not recommend seed-based products.

Where it comes from:

Alfalfa came from Persia and western Asia, where it was grown as fodder thousands of years ago. Arab growers called it al-fisfisa and prized it for horses; the Moors carried it into Spain, and from there it spread across Europe.

It entered Western herbal medicine properly in 19th-century North America. Eclectic physicians (a school of American plant-based doctors) used the leaf as a restorative for thin, run-down and recovering patients.

What does Alfalfa help with?

• High cholesterol: This is the best-studied use, and the evidence is still weak. Small, old studies of alfalfa seeds reported drops in total and LDL cholesterol (the "bad" kind), but they were tiny and not repeated in modern trials. The form that was tested — concentrated seed — is the form we advise against on safety grounds. Alfalfa leaf tea has not been shown to lower cholesterol. Do not use it in place of a statin or other prescribed treatment.
• Poor appetite and recovery from illness: This is the classic Western folk use and it rests on tradition, not trials. Nineteenth-century herbalists gave alfalfa leaf to people who were underweight or run down after illness. Alfalfa leaf is genuinely nutritious, which makes the traditional reasoning understandable. No human trial has tested it for appetite or recovery.
• Menopause symptoms such as hot flushes: There is no good human evidence for this use. The idea rests on coumestrol, a weak plant oestrogen in the leaf. Some small studies combined alfalfa with sage, which makes it impossible to tell which herb did anything. If you have or have had a hormone-sensitive cancer, this use is not for you — see the safety section.
• Low vitamin K and mineral intake: Here alfalfa acts as a food rather than a medicine. The dried leaf is a real source of vitamin K, calcium, potassium and iron. That same vitamin K content is exactly why alfalfa clashes with warfarin and similar blood thinners. A varied diet is a simpler and safer way to get these nutrients.
• Mild fluid retention: Traditional use only. European and American herbalists listed alfalfa as a mild diuretic (something that makes you pass more urine). No human trial has tested this. Swelling in the legs or belly can signal heart, kidney or liver trouble, so get it checked rather than treating it yourself.

Which foods are rich in Alfalfa?

1. Alfalfa sprouts: the raw sprouted seed, eaten in salads and sandwiches; tasty, but the main food-poisoning risk
2. Alfalfa leaf tea: the dried leaf, the safest everyday form
3. Green food powders: often blended with wheatgrass, barley grass and spirulina

Practical Tips:

If your immune system is weak, or you are pregnant, older or feeding a young child, cook sprouts through or skip them.

What are the side effects of Alfalfa?

• Gas and bloating
• Loose stools or stomach upset
• Skin rash
• Skin burning more easily in sunlight
• Lupus-like symptoms: joint pain, fever, rash (rare, mainly with seeds or sprouts)
• Low blood cell counts causing pale skin, tiredness and easy bruising (rare, reported with seeds)
• Food poisoning from raw sprouts contaminated with salmonella or E. coli (bacteria that cause severe diarrhoea)

Good to know:

For most people, alfalfa leaf in food or tea amounts causes nothing worse than wind and a loose stomach. Those effects are common and settle when you stop.

The serious effects are rare but real, and they are why this page is not rated routine. Alfalfa seeds and sprouts have been linked to a lupus-like illness (an autoimmune reaction, where the immune system attacks the body) and, in a few reports, to low blood cell counts.

People who already have lupus have had flares after taking alfalfa. Raw sprouts are also a well-known cause of food poisoning outbreaks.

How much Alfalfa should you take?

• Recommended daily: There is no officially established dose for alfalfa, so the figures below are what traditional practice and product labels commonly use. Dried leaf tea: 5 to 10 g of dried leaf steeped in hot water, one to three times a day. Tablets or capsules of leaf powder: roughly 1 to 3 g a day, split across doses. Tincture: follow the label, usually 5 to 10 ml a day. We do not recommend alfalfa seed or concentrated sprout supplements at any dose, because of the canavanine content.
• Best time of day: Split the dose through the day, usually with meals. The tea is often drunk in the morning and again in the afternoon. Late-evening tea may have you getting up at night to pass urine.
• With or without food: Take it with food. This softens the gas and bloating that alfalfa can cause, and food may help you absorb the fat-soluble vitamins (vitamins that dissolve in fat, such as vitamin K).
• Time to effect: Nothing happens quickly. Any change in appetite or wellbeing is usually described over two to four weeks. Cholesterol changes, if they happen at all, would take at least two to three months to show on a blood test.
• How long to take it: Treat alfalfa as a short-run supplement, not a daily habit for years. Four to eight weeks is a sensible trial, then stop and take stock. If nothing has changed, stop. Stop straight away and speak to a doctor if you notice joint pain, a rash, a fever or unusual tiredness.