Since ancient times, herbs have been used as natural treatments for various illnesses, including viral infections.Due to their concentration of potent plant compounds, many herbs help fight viruses and are favored by practitioners of natural medicine.At the same time, the benefits of some herbs are only supported by limited human research, so you should take them with a grain of salt.Here are 15 herbs with powerful antiviral activity.
Oregano is a popular herb in the mint family that’s known for its impressive medicinal qualities. Its plant compounds, which include carvacrol, offer antiviral properties. In a test-tube study, both oregano oil and isolated carvacrol reduced the activity of murine norovirus (MNV) within 15 minutes of exposure (1). MNV is highly contagious and the primary cause of stomach flu in humans. It is very similar to human norovirus and used in scientific studies because human norovirus is notoriously difficult to grow in laboratory settings (2). Oregano oil and carvacrol have also been shown to exhibit antiviral activity against herpes simplex virus type-1 (HSV-1); rotavirus, a common cause of diarrhea in infants and children; and respiratory syncytial virus (RSV), which causes respiratory infections (3, 4, 5).
Also a member of the mint family, sage is an aromatic herb that has long been used in traditional medicine to treat viral infections (6). The antiviral properties of sage are mostly attributed to compounds called safficinolide and sage one, which are found in the leaves and stem of the plant (7). Test-tube research indicates that this herb may fight human immunodeficiency virus type 1 (HIV-1), which can lead to AIDS. In one study, sage extract significantly inhibited HIV activity by preventing the virus from entering target cells (8). Sage has also been shown to combat HSV-1 and Indiana vesiculovirus, which infects farm animals like horses, cows, and pigs (9, 10).
Many types of basil, including the sweet and holy varieties, may fight certain viral infections. For example, one test-tube study found that sweet basil extracts, including compounds like apigenin and ursolic acid, exhibited potent effects against herpes viruses, hepatitis B, and enterovirus (11). Holy basil, also known as tulsi, has been shown to increase immunity, which may help fight viral infections. In a 4-week study in 24 healthy adults, supplementing with 300 mg of holy basil extract significantly increased levels of helper T cells and natural killer cells, both of which are immune cells that help protect and defend your body from viral infections (12).
Fennel is a licorice-flavored plant that may fight certain viruses. A test-tube study showed that fennel extract exhibited strong antiviral effects against herpes viruses and parainfluenza type-3 (PI-3), which causes respiratory infections in cattle (13). What’s more, trans-anethole, the main component of fennel essential oil, has demonstrated powerful antiviral effects against herpes viruses (14).According to animal research, fennel may also boost your immune system and decrease inflammation, which may likewise help combat viral infections (15).
Garlic is a popular natural remedy for a wide array of conditions, including viral infections. In a study in 23 adults with warts caused by human papillomavirus (HPV), applying garlic extract to affected areas twice daily eliminated the warts in all of them after 1–2 weeks (16, 17). Additionally, older test-tube studies note that garlic may have antiviral activity against influenza A and B, HIV, HSV-1, viral pneumonia, and rhinovirus, which causes the common cold. However, current research is lacking (18). Animal and test-tube studies indicate that garlic enhances immune system response by stimulating protective immune cells, which may safeguard against viral infections (19).
Peppermint is known to have powerful antiviral qualities and commonly added to teas, extracts, and tinctures meant to naturally treat viral infections. Its leaves and essential oils contain active components, including menthol and rosmarinic acid, which have antiviral and anti-inflammatory activity (24). In a test-tube study, peppermint-leaf extract exhibited potent antiviral activity against respiratory syncytial virus (RSV) and significantly decreased levels of inflammatory compounds (25).
Rosemary is frequently used in cooking but likewise has therapeutic applications due to its numerous plant compounds, including oleanolic acid (26). Oleanolic acid has displayed antiviral activity against herpes viruses, HIV, influenza, and hepatitis in animal and test-tube studies (27). Plus, rosemary extract has demonstrated antiviral effects against herpes viruses and hepatitis A, which affects the liver (28, 29).
Ginger products, such as elixirs, teas, and lozenges, are popular natural remedies — and for good reason. Ginger has been shown to have impressive antiviral activity thanks to its high concentration of potent plant compounds. Test-tube research demonstrates that ginger extract has antiviral effects against avian influenza, RSV, and feline calicivirus (FCV), which is comparable to human norovirus (43, 44, 45). Additionally, specific compounds in ginger, such as gingerols and zingerone, have been found to inhibit viral replication and prevent viruses from entering host cells (46).
The bottom line
Herbs have been used as natural remedies since ancient times. Common kitchen herbs, such as basil, sage, and oregano, as well as lesser-known herbs like astragalus and sambucus, have powerful antiviral effects against numerous viruses that cause infections in humans. It’s easy to add these powerful herbs to your diet by using them in your favorite recipes or making them into teas. However, keep in mind that most research has been conducted in test tubes and animals using concentrated extracts. Therefore, it’s unclear whether small doses of these herbs would have the same effects. If you decide to supplement with extracts, tinctures, or other herbal products, consult your healthcare provider to ensure safe usage.