A Guide to Common Medicinal Herbs
Here's a look at some of the more common medicinal herbs. Most herbs have not been
completely tested to see how well they work or to see if they interact with other
herbs, supplements, medicines, or foods. Products added to herbal preparations may
also cause interactions. Be aware that "natural" does not mean "safe." It's important
to tell your healthcare providers about any herb or dietary supplement you are using.
Chamomile
(Flower)
Considered by some to be a cure-all, chamomile is commonly used in the U.S. as ananxiolytic
and sedative for anxiety and relaxation. It is used in Europe for wound healing and
to reduce inflammation or swelling. Few studies have looked at how well it works for
any condition. Chamomile is used as a tea or applied as a compress. It is considered
safe by the FDA. It may increase drowsiness caused by medicines or other herbs or
supplements. Chamomile may interfere with the way the body uses some medicines, causing
too high a level of the medicine in some people. As with any medicinal herb, talk
with your healthcare provider before taking it.
Echinacea
(Leaf, stalk, root)
Echinacea is commonly used to treat or prevent colds, flu, and infections, and for
wound healing. More than 25 published studies looked at how well Echinacea worked
to prevent or shorten the course of a cold, but none were conclusive. A 2014 study
compared Echinacea with a placebo for treating colds. Results found that Echinacea
did not have any effect on a cold. Other studies have also shown that long-term use
can affect the body's immune system. It should not be used with medicines that can
cause liver problems. People allergic to plants in the daisy family may be more likely
to have an allergic reaction to Echinacea. The daisy family includes ragweed, chrysanthemums,
marigolds, and daisies.
Feverfew
(Leaf)
Feverfew was traditionally used to treat fevers. It is now commonly used to prevent
migraines and treat arthritis. Some research has shown that certain feverfew preparations
can prevent migraines. Side effects include mouth ulcers and digestive irritation.
People who suddenly stop taking feverfew for migraines may have their headaches return.
Feverfew should not be used with nonsteroidal anti-inflammatory medicines because
these medicines may change how well feverfew works. It should not be used with warfarin
or other anticoagulant medicines.
Garlic
(Cloves, root)
Garlic is used for lowering cholesterol and blood pressure. It has antimicrobial effects.
Reports from small, short-term, and poorly described studies show that it may cause
small reductions in total and LDL cholesterol. But German research results on garlic's
cholesterol-lowering effect have been distorted for a positive effect, the FDA says.
Researchers are currently exploring garlic's possible role in preventing cancer. The
FDA considers garlic safe. It should not be used with warfarin, because large amounts
of garlic may affect clotting. For the same reason, large amounts should not be taken
before dental procedures or surgery.
Ginger
(Root)
Ginger is used to ease nausea and motion sickness. Research suggests that ginger can
relieve nausea caused by pregnancy or chemotherapy. Other areas under investigation
are in surgery and for nausea caused by motion. Reported side effects include bloating,
gas, heartburn, and nausea.
Gingko
(Leaf)
Ginkgo leaf extract has been used to treat a variety of conditions such as asthma,
bronchitis, fatigue, and tinnitus. It is also used to improve memory and to prevent
dementia and other brain disorders. Some studies have supported its slight effectiveness.
But exactly how gingko works isn't understood. Only extract from leaves should be
used. Seeds contain ginkgo toxin. This toxin can cause seizures and, in large amounts,
death. Because some information suggests that ginkgo can increase the risk of bleeding,
it should not be used with nonsteroidal anti-inflammatory medicines, anticoagulants,
anticonvulsant medicines, or tricyclic antidepressants.
Ginseng
(Root)
Ginseng is used as a tonic and aphrodisiac, even as a cure-all. Research is uncertain
how well it works, partly because of the difficulty in defining "vitality" and "quality
of life." There is a large variation in the quality of ginseng sold. Side effects
are high blood pressure and tachycardia. It's considered safe by the FDA, but shouldn't
be used with warfarin, heparin, nonsteroidal anti-inflammatory medicines, estrogens,
corticosteroids, or digoxin. People with diabetes should not use ginseng.
Goldenseal
(Root, rhizome)
Goldenseal is used to treat diarrhea, and eye and skin irritations. It is also used
as an antiseptic. It is also an unproven treatment for colds. Goldenseal contains
berberine, a plant alkaloid with a long history of medicinal use in both Ayurvedic
and Chinese medicine. Studies have shown that goldenseal is effective for diarrhea.
But it's not recommended because it can be poisonous in high doses. It can cause skin,
mouth, throat, and gastric irritation. It is also not recommended because of the plant's
endangered species status.
Milk thistle
(Fruit)
Milk thistle is used to treat liver conditions and high cholesterol, and to reduce
the growth of cancer cells. Milk thistle is a plant that originated in the Mediterranean
region. It has been used for many different illnesses over the last several thousand
years, especially liver problems. Although study results are uncertain, some promising
information exists.
Saint John's wort
(Flower, leaf)
Saint John's wort is used as an antidepressant. Recent studies have not confirmed
that there is more than a slight effect on depression. More research is needed to
determine the best dose. A side effect is sensitivity to light, but this is only noted
in people taking large doses of the herb. St. John's work can cause a dangerous interaction
with other commonly used medicines. Always talk with your healthcare provider before
using this herb.
Saw palmetto
(Fruit)
Saw palmetto is used to treat benign prostatic hypertrophy (BPH). But recent studies
have not found it to work well for this condition. Side effects are digestive upset
and headache, both mild.
Valerian
(Root)
Valerian is used to treat sleeplessness and to reduce anxiety. Research suggests that
valerian may be a helpful sleep aid, but there are no well-designed studies to confirm
the results. In the U.S., valerian is used as a flavoring for root beer and other
foods. As with any medicinal herb, talk with your healthcare provider before taking
it.
