What Is Alfalfa?

Alfalfa (Medicago sativa) is a perennial plant (meaning it regrows every year). It belongs to the Fabaceae family that has long been used in traditional medicine to treat various health conditions. Alfalfa is high in vitamins, calcium, potassium, phosphorus, and iron.

People eat alfalfa fresh in the form of sprouts. It has a sweet, bitter, grassy flavor. It is also available as a supplement.

Some people claim it can help with diabetes, high cholesterol, arthritis, urinary tract infections, menstrual problems, and other disorders. However, there is little evidence to support these supposed benefits.

This article explains alfalfa's uses, benefits, and potential side effects. It also discusses how you can safely incorporate alfalfa into your diet.

Uses of Alfalfa

Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian, pharmacist, or doctor. No supplement is intended to treat, cure, or prevent disease. 

Alfalfa is a low-calorie, nutrient-dense food. One cup of alfalfa sprouts has only 8 calories but delivers 0.2 grams fat, 0.7 grams carbohydrate, 0.6 grams fiber, and 1.3 grams protein. In addition, alfalfa's rich soluble fiber content makes it a good food for controlling cholesterol and feeling full.

Alfalfa also contains several essential vitamins and minerals, including:

• Calcium
• Iron
• Potassium
• Phosphorus
• Vitamin A
• Vitamin C
• Vitamin E
• Vitamin K

Beyond its dietary benefits, alfalfa is often used in alternative therapies to treat medical conditions and metabolic disorders. However, for the most part, the scientific evidence to support these claims is weak.

High Cholesterol

Alfalfa contains saponins, substances that inhibit your body's ability to digest proteins and absorb minerals. However, these anti-nutrients are not all bad. In plants, they exist to protect them from infection and from getting destroyed by insects.

Anti-nutrients can also offer health benefits. For example, animal studies have shown a direct association between increasing doses of alfalfa saponin extract and decreasing blood cholesterol levels in rats.

Whether it can achieve the same effect in humans is uncertain. Alfalfa has been studied little as a potential treatment of hypercholesterolemia (high cholesterol), and therefore, further research is needed.

Diabetes

Fiber-rich foods like alfalfa may help control blood sugar by slowing glucose (sugar) absorption in the intestines. As such, alfalfa may be supportive for diabetes or prediabetes. There has been some evidence of this in animal studies.

A 2015 study published in Interventional Medicine and Applied Science evaluated the effect of alfalfa extract on rats with chemically-induced diabetes. Researchers divided 40 rats into two control groups (a non-diabetic and a diabetic group) and two intervention groups (both diabetic). The control groups received the usual food and water. One diabetic group received 250 mg/kg extract of alfalfa for 21 days. The other diabetic group received a 500 mg/kg dose for 21 days.

After treatment, the two diabetic groups experienced a reduction in blood glucose, cholesterol, triglycerides, and "bad" low-density lipoprotein (LDL) cholesterol compared to the diabetic control group. There was also a significant increase in "good" high-density lipoprotein (HDL) cholesterol. These results were dose-dependent, meaning that the rats in the higher-dose alfalfa group had more significant improvement.

Again, this study was conducted on animals. Therefore, it is unclear whether it can achieve the same benefits in humans. Further research is needed.

Urinary Tract Disorders

Some herbalists use alfalfa as a natural diuretic ("water pill") for treating urinary tract disorders, including renal calculi (kidney stones) and urinary tract infections (UTIs).

A 2016 study looked at which plants herbalists in Iran used to treat kidney and urinary stones. The study found that alfalfa was among 18 species herbalists relied on; however, the study did not evaluate the safety or effectiveness of the herbs.

Reproductive Health Issues

Alfalfa contains a group of molecules called isoflavones. These are a type of phytoestrogen, a plant-based hormone that mimics the action of the hormone estrogen. As such, some argue that alfalfa might be an effective remedy for menstrual disorders such as premenstrual syndrome (PMS) and menopause.

An older 1998 study evaluated the use of alfalfa and sage in menopausal people with hot flashes. For three months, 30 participants with these symptoms took extracts of these plants. After therapy, night sweats and hot flashes completely disappeared for 20 participants, four had good improvement, and six had reduced symptoms.

In a 2011 study, researchers evaluated the effect of estrogenic supplements (including alfalfa) on quality of life, fatigue, and hormonal symptoms in people with breast cancer. In this prospective study of 788 participants with breast cancer, researchers collected information on participants' use of botanical supplements and their symptoms.

After 40 months, participants answered a survey about how bothered they were in the past year by common hormonal symptoms, fatigue, and self-image. Those who used alfalfa were less likely to report disturbed sleep than those who did not use alfalfa. However, this was an exploratory study and did not include controls or comparisons.

While there's some research on alfalfa's potential role in hormonal conditions, the studies are limited, older, and speculative.

Breast Milk Production

Alfalfa is regarded as a plant-based galactagogue, meaning it can stimulate breast milk production. Alfalfa is, in fact, one of the most popular traditional medicines used as a galactagogue alongside black seed (Nigella sativa) and fenugreek (Trigonella foenum-graecum).

A 2014 review in the journal Procedia explored herbal galactagogue usage, including alfalfa, in breastfeeding parents. The survey evaluated responses from 83 participants who used herbal galactagogues and reported their level of satisfaction.

Alfalfa was the most commonly used herb, followed by black seed and fenugreek. A majority of participants—67—reported satisfaction with the herbs, while six were unsatisfied, and 10 were unsure.

While this study suggests alfalfa may support milk production, it provides little evidence of how effective the treatment may be or what dose is needed.

Inflammation

As a nutrient-dense plant food, alfalfa fits the profile of an anti-inflammatory food. Some studies have reported that alfalfa suppresses the production of inflammatory compounds known as cytokines.

Some alternative healthcare providers believe this effect can reduce pain and inflammation associated with osteoarthritis or rheumatoid arthritis. Alfalfa is, in fact, one of the more popular ingredients used in herbal arthritis remedies.

However, to date, these benefits remain largely unproven. With rheumatoid arthritis, the underlying cause of inflammation is autoimmune (meaning the body's immune cells attack healthy joints). Alfalfa in no way alters this action.

Research has found the opposite—there is evidence that alfalfa can trigger acute symptoms of certain autoimmune diseases. For example, some studies found that alfalfa sprouts induced lupus-like symptoms in otherwise healthy people and reactivated symptoms in those with inactive disease.

Since alfalfa seems to activate the immune system, those with autoimmune diseases should avoid alfalfa.

What Are the Side Effects of Alfalfa?

Alfalfa sprouts are usually safe and nutritious but may cause side effects in some people. These side effects may be common or severe.

Common Side Effects

Due to its high fiber content, consuming raw alfalfa can cause gastrointestinal issues, including:

• Gas
• Abdominal discomfort
• Diarrhea

A greater (and more common) concern is the contamination of alfalfa sprouts by bacterial pathogens such as Salmonella or E. coli.

Symptoms of Salmonella and E. coli infection include:

• Diarrhea
• Fever
• Abdominal cramps

Contact your healthcare provider immediately if you experience symptoms like these hours or even days after eating fresh alfalfa.

Severe Side Effects

Because of its estrogenic effects, people with hormone-sensitive cancers such as breast, prostate, cervical, or uterine cancers should avoid alfalfa. For these same reasons, those who are pregnant and breastfeeding should avoid alfalfa.

Alfalfa sprouts also contain an amino acid called L-canavanine that can trigger inflammation in people with certain autoimmune diseases, particularly lupus. As a result, eating alfalfa or taking it as a supplement can trigger acute lupus symptoms.

If you have an autoimmune condition, including multiple sclerosis or rheumatoid arthritis, speak with your healthcare provider before eating alfalfa sprouts or taking alfalfa supplements.

Dosage: How Much Alfalfa Should I Take?

According to the National Library of Medicine, there is not enough reliable evidence to say what an appropriate dosage of alfalfa might be. Supplements often come in doses ranging from 5 grams to 10 grams.

What Happens If I Take Too Much Alfalfa?

When taking an alfalfa supplement in any form, never exceed the dose on the product label. In addition, alfalfa supplements are intended for short-term use. Unfortunately, little is known about the long-term safety of alfalfa supplements.

Fresh alfalfa sprouts are generally considered safe in people with typical immune systems. Even so, there always is a risk of bacterial contamination with any store-bought sprouts.

Before starting a supplement of any kind, including alfalfa, talk to a healthcare provider to see if it is safe in your situation and determine an appropriate dose.

Drug Interactions

Alfalfa supplements may interact with certain medications. However, it is unknown how strong these interactions may be or if they may require a dose adjustment or change in treatment. However, as a general rule, higher doses tend to increase the potential for drug interactions.

Anticoagulants

Anticoagulants (blood thinners) like Coumadin (warfarin) present a significant potential for interaction. That's because the high vitamin K content in alfalfa (which promotes clotting) may undermine the drug's effectiveness.

Be sure to check with a healthcare provider before starting alfalfa if you take an anticoagulant. And have your blood checked regularly to determine whether you may need to modify your medication dose.

Diabetes Medications

Diabetes medications pose a moderate risk for interaction. They can be affected by alfalfa, causing a further drop in blood sugar and an increased risk of hypoglycemia (low blood sugar).

Check with a healthcare provider before combining these medications and supplements. If you do take both, monitor your blood glucose levels closely.

Hormones

Hormonal contraceptives are a moderate risk for interactions. Alfalfa may compromise the estrogenic effects of the hormones and make them less effective in preventing pregnancy.

Similarly, if you take estrogen as hormone therapy, alfalfa may make it less effective.

Talk to a healthcare provider before taking alfalfa if you are on hormonal birth control, and use a backup form of birth control, like condoms, if you take both.

Immunosuppressant Drugs

Immunosuppressant drugs, like corticosteroids and cyclosporine, are a moderate risk when taken with alfalfa. Alfalfa may reduce the effects of these drugs due to the pro-inflammatory effects of L-canavanine in alfalfa. If you take immunosuppressant medication, talk to a healthcare provider before taking alfalfa.

Photosensitizing Drugs

Photosensitizing drugs are those that cause your skin to be sensitive to sunlight. These medications pose a moderate risk when taken with alfalfa. They may increase the risk of sunburn when taken together. So, be sure to talk to a healthcare provider before combining them. In addition, use sunscreen and wear protective clothing when in the sun.

Herbs

Alfalfa may interact with certain herbs and supplements. These include:

• Aloe
• Bishop's weed
• Bitter melon
• Chlorophyll
• Cinnamon
• Chromium
• Iron
• Khella
• Prickly pear cactus
• St. John's wort
• Vitamin E
  

It is essential to carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included. In addition, please review the supplement label with your healthcare provider to discuss any potential interactions with foods, other supplements, and medications.

How To Store Alfalfa

Store alfalfa supplements in a cool, dry place. Keep alfalfa away from direct sunlight. Discard after one year or as indicated on the packaging.

Fresh alfalfa should be refrigerated and eaten within two to three days.

Sources of Alfalfa and What to Look For

When eating fresh alfalfa or taking alfalfa in supplement form, there are several things to consider.

Food Sources of Alfalfa

You can purchase fresh alfalfa sprouts in many grocery stores. To reduce the risk of bacterial contamination, purchase sprouts that have been properly refrigerated and are not slimy, wilted, discolored, or smelly. You should store sprouts in the refrigerator at around 40 degrees F.

Before eating them, wash and rinse sprouts thoroughly to mitigate potential exposure to bacterial contaminants. Better yet, cook the sprouts rather than eating them raw. The same applies to alfalfa juice. Cooking will alter the flavor and texture but retain some nutritional value.

Alternately, purchase alfalfa seeds online or at a health food store and sprout them at home.

Alfalfa Supplements

Alfalfa supplements are widely available in vitamin shops and many health food stores. They come in a variety of preparations, including:

• Herbal tea
• Tincture
• Tablet
• Powder
• Dried herb

Nutritional supplements are not strictly regulated in the United States and can vary in quality from one brand to the next.

It is more difficult to assess the quality of the traditional Chinese remedy Mu Xu. According to the National Center for Complementary and Integrative Health, herbal remedies from China are sometimes tainted with drugs, heavy metals, pesticides, and other harmful ingredients. Therefore, it is best to avoid imported herbal remedies.

Summary

Alfalfa is a plant that is high in vitamins and minerals. People commonly eat it as a sprouted green. Some people take alfalfa in supplement form, too. While there is some research on purported health benefits, the evidence to support their use in treating health conditions is weak.

People with autoimmune conditions and hormone-related cancers should be cautious with taking alfalfa due to the effects on the immune system and the phytoestrogens in the plant. In addition, alfalfa can interact with many medications, hormones, herbs, and supplements.

A Word From Verywell

Alfalfa sprouts may be tasty and healthy, but keep in mind that fresh alfalfa sprouts pose a potential risk to young children, older adults, pregnant people, and anyone with a compromised immune system.

If you intend to use alfalfa for medicinal purposes, let your healthcare provider know so they can monitor you for side effects or possible drug interactions.