Herbs (L-Y)

*This information is provided for your convenience. It is not intended as medical advice or as a guide to self-medication. Please consult a qualified healthcare professional for advice on using medicinal herbs.

HERB NAMES:   A - E   |   F - K   |   L - Y

HERB	POSSIBLE USES	PRECAUTIONS
Lavender (Lavandula angustifolia)	Historically, lavender was used as an antiseptic and for mental health purposes. Today, the herb is used for conditions such as anxiety, restlessness, insomnia, and depression. Lavender is also used for headache, upset stomach, and hair loss.	Topical use of diluted lavender oil or use of lavender as aromatherapy is generally considered safe for most adults. However, applying lavender oil to the skin can cause irritation. Lavender oil is poisonous if taken by mouth. When lavender teas and extracts are taken by mouth, they may cause headache, changes in appetite, and constipation. Using lavender with sedative medications may increase drowsiness. Tell your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
Licorice Root (Glycyrrhiza glabra)	Licorice root has been used as a dietary supplement for stomach ulcers, bronchitis, and sore throat, as well as infections caused by viruses, such as hepatitis.	In large amounts, licorice containing glycyrrhizin can cause high blood pressure, salt and water retention, and low potassium levels, which could lead to heart problems. DGL products are thought to cause fewer side effects. The safety of using licorice as a supplement for more than 4 to 6 weeks has not been thoroughly studied. Taking licorice together with diuretics (water pills) or other medicines that reduce the body's potassium levels could cause dangerously low potassium levels. People with heart disease or high blood pressure should be cautious about using licorice. When taken in large amounts, licorice can affect the body's levels of a hormone called cortisol and related steroid drugs, such as prednisone. Pregnant women should avoid using licorice as a supplement or consuming large amounts of licorice as food, as some research suggests it could increase the risk of preterm labor. Tell your health care providers about any herb or dietary supplement you are using, including licorice root. This helps to ensure safe and coordinated care.
Milk Thistle (Silybum marinum)	Milk thistle is believed to have protective effects on the liver and improve its function. It is typically used to treat liver cirrhosis, chronic hepatitis (liver inflammation), and gallbladder disorders. Treatment claims also include: Lowering cholesterol levels. Reducing insulin resistance in people with type 2 diabetes who also have cirrhosis. Reducing the growth of cancer cells in breast, cervical, and prostate cancers	In clinical trials, milk thistle generally has few side effects. Occasionally, people report a laxative effect, upset stomach, diarrhea, and bloating. Milk thistle can produce allergic reactions, which tend to be more common among people who are allergic to plants in the same family (for example, ragweed, chrysanthemum, marigold, and daisy). It is important to inform your health care providers about any herb or dietary supplement you are using, including milk thistle. This helps to ensure safe and coordinated care.
Mistletoe (Viscum album L.)	Mistletoe has been used for centuries in traditional medicine to treat seizures, headaches, and other conditions. Mistletoe is used mainly in Europe as a treatment for cancer.	Raw, unprocessed mistletoe is poisonous. Eating raw, unprocessed European mistletoe or American mistletoe can cause vomiting, seizures, a slowing of the heart rate, and even death. American mistletoe is unsafe for medicinal use. In countries where commercial mistletoe is available by injection, such as Germany, those extracts are considered to be generally safe when used according to product directions and under the supervision of a health care provider. Injected mistletoe extract may cause itching or redness in the area of the injection. Less commonly, side effects may include more extensive skin reactions, low-grade fevers, or flu-like symptoms. There have been very rare reports of more serious allergic reactions, such as difficulty breathing. Because mistletoe has not yet been proven to be a safe and effective cancer treatment, it should not be used outside of clinical trials. It is important to inform your health care providers about any herb or dietary supplement you are using, including mistletoe. This helps to ensure safe and coordinated care.
Noni (Viscum album L.)	Noni has been traditionally used in Polynesia as a dye, but it also has a history of use as a topical preparation for joint pain and skin conditions. Today, people drink noni fruit juice as a general health tonic, as well as for cancer and chronic conditions such as cardiovascular disease and diabetes.	Noni is high in potassium. People who are on potassium-restricted diets because of kidney problems should avoid using noni. Several noni juice manufacturers have received warnings from the U.S. Food and Drug Administration about making unsubstantiated health claims. Although there have been few reported side effects from using noni, its safety has not been adequately studied. There have been reports of liver damage from using noni. It should be avoided if you have liver disease because it contains compounds that may make your disease worse. Tell your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
Peppermint Oil (Mentha x piperita)	Peppermint oil has been used for a variety of health conditions, including nausea, indigestion, and cold symptoms. Peppermint oil is also used for headaches, muscle and nerve pain, and stomach and bowel conditions such as irritable bowel syndrome.	Peppermint oil appears to be safe for most adults when used in small doses. Possible side effects include allergic reactions and heartburn. Capsules containing peppermint oil are often coated to reduce the likelihood of heartburn. If they are taken at the same time as medicines such as antacids, this coating can break down more quickly and increase the risk of heartburn and nausea. Tell your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
Red Clover (Trifolium pratense)	Historically, red clover has been used for cancer and respiratory problems, such as whooping cough, asthma, and bronchitis. Current uses of red clover are for menopausal symptoms, breast pain associated with menstrual cycles, high cholesterol, osteoporosis, and symptoms of prostate enlargement.	Red clover seems to be safe for most adults when used for short periods of time. No serious adverse effects have been reported. Because red clover contains estrogen-like compounds, there is a possibility that its long-term use would increase the risk of women developing cancer of the lining of the uterus. However, studies to date have been too brief (less than 6 months) to evaluate whether red clover has estrogen-like effects on the uterus. It is unclear whether red clover is safe for women who are pregnant or breastfeeding, or who have breast cancer or other hormone-sensitive cancers. Tell your health care providers about any herb or dietary supplement you are using, including red clover. This helps to ensure safe and coordinated care.
Saw Palmetto (Serenoa repens)	Saw palmetto is used mainly for urinary symptoms associated with an enlarged prostate gland (also called benign prostatic hyperplasia, or BPH). Saw palmetto is also used for other conditions, including chronic pelvic pain, bladder disorders, decreased sex drive, hair loss, and hormone imbalances.	Saw palmetto may cause mild side effects, including stomach discomfort. Some men using saw palmetto have reported side effects such as tender breasts and a decline in sexual desire. Tell your health care providers about any herb or dietary supplement you are using, including saw palmetto. This helps to ensure safe and coordinated care.
Soy (Glycine max)	Soy is available in dietary supplements, in forms such as tablets and capsules. Soy supplements may contain isoflavones or soy protein or both. Soybeans can be cooked and eaten or used to make tofu, soy milk, and other foods. Also, soy is sometimes used as an additive in various processed foods, including baked goods, cheese, and pasta.	Soy is considered safe for most people when used as a food or when taken for short periods as a dietary supplement. Minor stomach and bowel problems such as nausea, bloating, and constipation are possible. Allergic reactions such as breathing problems and rash can occur in rare cases. The safety of long-term use of soy isoflavones has not been established. Evidence is mixed on whether using isoflavone supplements, over time, can increase the risk of endometrial hyperplasia (a thickening of the lining of the uterus that can lead to cancer). Studies show no effect of dietary soy on risk for endometrial hyperplasia. Soy's possible role in breast cancer risk is uncertain. Until more is known about soy's effect on estrogen levels, women who have or who are at increased risk of developing breast cancer or other hormone-sensitive conditions (such as ovarian or uterine cancer) should be particularly careful about using soy and should discuss it with their health care providers. Tell your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
St. John's Wort (Hypericum perforatum)	St. John's wort has been used for centuries to treat mental disorders and nerve pain. In ancient times, herbalists wrote about its use as a sedative and a treatment for malaria, as well as a balm for wounds, burns, and insect bites. Today, St. John's wort is used by some for depression, anxiety, and/or sleep disorders.	St. John's wort may cause increased sensitivity to sunlight. Other side effects can include anxiety, dry mouth, dizziness, gastrointestinal symptoms, fatigue, headache, or sexual dysfunction. Research shows that St. John's wort interacts with some drugs. The herb affects the way the body processes or breaks down many drugs; in some cases, it may speed or slow a drug's breakdown. Drugs that can be affected include: Indinavir and possibly other drugs used to control HIV infection, Irinotecan and possibly other drugs used to treat cancer, Cyclosporine, which prevents the body from rejecting transplanted organs, Digoxin, which strengthens heart muscle contractions, Warfarin and related anticoagulants, Birth control pills and Antidepressants. When combined with certain antidepressants, St. John's wort may increase side effects such as nausea, anxiety, headache, and confusion. St. John's wort is not a proven therapy for depression. If depression is not adequately treated, it can become severe. Anyone who may have depression should see a health care provider. There are effective proven therapies available. It is important to inform your health care providers about any herb or dietary supplement you are using, including St. John's wort. This helps to ensure safe and coordinated care.
Thunder God Vine (Tripterygium wilfordii)	Thunder god vine has been used in traditional Chinese medicine for conditions involving inflammation or overactivity of the immune system. Orally, thunder god vine is taken for excessive menstrual periods or autoimmune diseases, including rheumatoid arthritis, multiple sclerosis, and lupus. Thunder god vine preparations are also applied to the skin for rheumatoid arthritis.	Thunder god vine can cause severe side effects and can be poisonous if it is not carefully extracted from the skinned root. Other parts of the plant-including the leaves, flowers, and skin of the root-are highly poisonous and can cause death. The extract of thunder god vine used in the NIAMS study was well tolerated. However, thunder god vine can cause diarrhea, upset stomach, hair loss, headache, menstrual changes, and skin rash. Thunder god vine has been found to decrease bone mineral density in women who take the herb for 5 years or longer. This side effect may be of particular concern to women who have osteoporosis or are at risk for the condition. Thunder god vine decreases sperm count and so may be associated with male infertility. Tell your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
Turmeric (Curcuma longa)	In traditional Chinese medicine and Ayurvedic medicine turmeric has been used to aid digestion and liver function, relieve arthritis pain, and regulate menstruation. Turmeric has also been applied directly to the skin for eczema and wound healing. Today, turmeric is used for conditions such as heartburn, stomach ulcers, and gallstones. It is also used to reduce inflammation, as well as to prevent and treat cancer.	Turmeric is considered safe for most adults. High doses or long-term use of turmeric may cause indigestion. In animals, high doses of turmeric have caused liver problems. No cases of liver problems have been reported in people. People with gallbladder disease should avoid using turmeric as a dietary supplement as it may worsen the condition. Tell your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
Valerian (Valeriana officinalis)	Valerian has long been used for sleep disorders and anxiety. Valerian has also been used for other conditions, such as headaches, depression, irregular heartbeat, and trembling.	Studies suggest that valerian is generally safe to use for short periods of time (for example, 4 to 6 weeks). No information is available about the long-term safety of valerian. Valerian can cause mild side effects, such as headaches, dizziness, upset stomach, and tiredness the morning after its use. Tell your health care providers about any herb or dietary supplement you are using, including valerian. This helps to ensure safe and coordinated care.
Yohimbine (Pausinystalia yohimbe)	Yohimbe bark has traditionally been used in Africa as an aphrodisiac (to increase sexual desire). The herb is currently used for sexual dysfunction, including erectile dysfunction in men.	Yohimbe has been associated with high blood pressure, increased heart rate, headache, anxiety, dizziness, and sleeplessness. Yohimbe can be dangerous if taken in large doses or for long periods of time. People should use caution if taking yohimbe with MAO inhibitors or medicines for high blood pressure. Yohimbe should not be combined with tricyclic antidepressants or phenothiazines (a group of medicines used mostly for mental health conditions such as schizophrenia). People with kidney problems and people with psychiatric conditions should not use yohimbe. Tell your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.

HERB NAMES:   A - E   |   F - K   |   L - Y  

For more information on herbs:

National Center for Complementary and Alternative Medicine (NCCAM)

Sources:
Herbs at a Glance - National Center for Complimentary and Alternative Medicine.
Dietary Fact Sheets - US Army Center for Health Promotion and Preventive Medicine
What Patients Need to Know About Herbal Therapy - Veterans Affairs Palo Alto Health Care System