The homeopathic mixture oscillococcinum is very popular in Europe, where it originated, and has gained increasing popularity in the U.S. Studies have shown that oscillococcinum may reduce the duration of the flu and the severity of some symptoms, but there is no evidence that it prevents the flu.
Garlic contains allicin, a compound that has been shown to have antiviral properties. One small study suggests it might help prevent colds, although evidence is mixed. Fresh, uncooked garlic is the most potent form. If you would rather use a supplement, look for one that contains 1.3% allicin. Garlic supplements can raise the risk of bleeding, so people taking blood thinners should ask their doctor before taking them.
Although echinacea has been touted to prevent or fight a cold, recent studies are conflicting as to whether it is beneficial for a cold or the flu. Studies have been done to examine whether echinacea can prevent, reduce the severity, and decrease the duration of illness. Unfortunately, none of these studies have shown a positive benefit. One criticism of the studies is that there are differing opinions regarding the best echinacea species, plant part, active componet, and the dose.
If you want to try echinacea supplements, pick a brand that uses the stems, leaves, and flowers of the Echinacea purpurea plant rather than the root. Don't take echinacea for more than eight weeks -- research suggests that using it for a long period of time may damage the immune system. People who are allergic to ragweed should not take echinacea.
Some research shows elderberry extracts might help reduce flu symptoms when given within the first 24 to 48 hours of symptoms. There are no known side effects of elderberry extract supplements when taken for up to five days. Ingesting the elderberry plant itself should be avoided, as it can cause nausea, vomiting, and diarrhea.
Other herbal remedies that may help when you have flu include:
- Lozenges containing licorice and slippery elm (may help ease sore throats and coughs from post-nasal drip)
- Ginger tea (for nausea)