10 Best Immune-Boosting Herbs for Flu Season (That Actually Work!)

Once again, flu season is upon us—and I’m guessing many of you have already caught one of the bugs making their rounds. Fortunately, we have a plethora of God-given herbs to turn to when illness strikes. These immune-boosting, fever-reducing, congestion-clearing, headache-relieving, and virus-fighting natural remedies can help ease even the toughest symptoms. Here are 10 of the best immune-boosting herbs to keep you strong and healthy this flu season!

1. Ginger — The Warming Root That Fights Inflammation

This warming root, favoured for its spicy notes and aromatic flavours, has powerful medicinal properties that make it a go-to herb for combating flus and colds.

First, ginger contains gingerol, a bioactive compound that reduces inflammation, provides pain relief, and has anti-microbial and immune-boosting benefits. These properties make it ideal for treating a sore throat, easing a cough, and bolstering the immune system to fight off viral infections.

When heated, gingerol converts to the compound, shogaol, which has even stronger anti-inflammatory and antiviral effects. This means preparing ginger in a hot soup or tea is even better for optimal flu-fighting benefits.

Ginger Tea Preparation

Try slicing a thumb of ginger and simmering for 20 minutes in 3 cups of water. Serve in a mug with a little honey and lemon if desired.

Ginger Soup Preparation

One of my favourite soups when I’m sick is a vegetarian version of a Filipino soup known as tinola. It’s an excellent flu-busting soup full of antiviral ingredients such as garlic, ginger, and papaya. You can find plant-based versions of this recipe online.

2. Echinacea — The Classic Immune Booster

The purple coneflower, also known as echinacea, is well known for its immune-boosting properties and is a popular first defence herbal supplement to take at the onset of a cold or flu. Echinacea can reduce the chance of developing an infection by more than half, and can shorten its duration and severity.

The secret behind echinacea’s effectiveness is in its ability to stimulate the production of white blood cells. More white blood cells mean a stronger immune response against invading pathogens.

How to Take Echinacea

Echinacea can be taken in many forms, including tea, tincture, lozenge, or capsule. Remember to take it with food or plenty of water.

Echinacea is most effective when taken at the first signs of illness. It can also be combined with elderberry for maximum effectiveness.

3. Peppermint — Soothes the Respiratory Tract

This is a must-have herb during flu season for its soothing effects, refreshing taste, and natural healing power. Peppermint tea is a staple in my pantry and a favourite with my kids whenever they’re under the weather. Its pleasant flavour makes it the perfect companion for other flu-fighting herbs, enhancing both taste and effectiveness.

The active compounds menthol and eucalyptol give peppermint its signature cooling aroma and natural decongestant properties—they help open airways, loosen mucus, and make breathing easier. These same compounds also soothe sore throats and calm irritated tissues, offering a comforting sense of relief during illness.

How to Use Peppermint

Tea: Drinking Peppermint tea with a little honey is my personal favourite. I often add it with other herbs such as catnip and mullein to target a variety of symptoms.

Essential Oil: Adding peppermint oil to a diffuser is another great way to benefit from its antimicrobial and decongestant properties. Or try making your own eucalyptus peppermint salve to rub on the chest and throat.

4. Licorice Root — Soothes Coughs and Throats

This is the first herb I often reach for when I’m getting a sore throat. Its sweet taste and deeply soothing action make it an easy tea to drink.

Glycyrrhizin is the compound that gives licorice its sweet taste and powerful healing properties. It works by coating and protecting mucus membranes, such as the throat. This action eases coughs and irritated throats, and respiratory tracts.

Not only does glycyrrhizin taste good and soothe, but it’s also been shown to have antiviral activity against the flu, RSV, and coronaviruses. It’s believed it does this by hampering the virus from replicating and by supporting the immune system.

Best Ways to Take Licorice Root for Health Benefits

My favourite way to use licorice root is by making tea. You can find licorice root at a health food store or purchase the already-made tea.

Feel free to add honey for extra benefits if desired—but it’s not necessary—as licorice root is naturally sweet!

5. Mullein — Clears the Lungs and Fights Infection

Mullein is considered a weed in many parts of the world, and can be found growing in dry, sunny, open areas in temperate regions such as Europe and North America. While it’s a stubborn plant to get rid of, it’s an incredibly useful medicinal herb to have on hand.

I only discovered mullein a couple of years ago after a friend brought a bag of it over to help with a cough I’d been struggling with for some time. It worked phenomenally well, clearing up my cough within a couple of hours of taking it.

Mullein has been used for centuries to treat a variety of ailments, but it’s most popularly used for respiratory infections. Mullein’s expectorant properties help clear airways by loosening phlegm, making it easier to expel. It’s also antiviral and antibacterial, making it an excellent choice for both viral and bacterial infections.

Best Ways to Take Mullein for Respiratory Health

Tea: Steep a tablespoon of dried mullein leaves in 10 oz of boiling water. Add a lemon slice and a little honey for taste.

Tincture: Mullein can be found in tincture form from many herbal supplement providers.

Read more about the benefits of mullein tea here.

6. Yarrow — The Fever-Fighting Herb

Yarrow is a wildflower typically found in meadows and along roadsides in the northern hemisphere. It’s crowned with delicate-looking white flowers that, along with the leaves, can be used medicinally to treat a variety of health issues.

One of yarrow’s impressive properties is that of an immune booster. Like echinacea, it’s best taken when the first symptoms of a cold or flu appear. When taken early, it’s been known to alleviate a cold within the first 24 hours of illness.

Yarrow is also an effective fever reducer. Drinking a cup of yarrow tea induces sweating, which lowers body temperature.

How to Use Yarrow

I make tea with dried yarrow and add honey and lemon. Learn how to make yarrow tea here.

Dried yarrow can be found at health food stores and online retailers.

Safety Precautions

While yarrow tea is safe for most people, certain individuals should avoid using it:

Pregnant women should not take yarrow as it can stimulate uterine contractions.

People on blood-thinning medications and those with bleeding disorders should not consume yarrow tea.

7. Catnip – Calming Herb that Supports Recovery

This amazing herb is not just for cats! It has incredible healing applications that most are unaware of. I grow catnip every summer in my garden because of how often we use it throughout the year. I find my own crop is more potent than what I can find in stores.

Because of how safe and effective catnip is, it’s one of my favourite herbs to use when my kids are sick. It’s antimicrobial, breaks fevers, soothes sore throats, and loosens phlegm, perfect for viral and bacterial infections. Combine this with its pain-relieving and mild sedative properties, and you have an all-star flu-buster!

How to Use Catnip

Catnip is easily made into a warm, soothing tea. Find out how to make catnip tea here.

8. Lemon Balm – Calming and Antiviral

A refreshing-tasting, citrusy herb, lemon balm is a member of the mint family and has several healing properties. Historically, it has been used to alleviate feelings of stress, anxiety, and depression due to its ability to relax the nervous system; however, it also has strong antiviral properties, making it an ideal herb to reach for when you’re feeling sick with a cold or flu. Lemon balm tea is especially effective against the shingles and herpes viruses, and can be taken internally or applied topically to affected areas.

Lemon balm is also high in infection-fighting antioxidants like rosmarinic acid and the phenolic compound eugenol, which supports immune function by reducing inflammation in the body. These compounds are also responsible for easing headaches and tension, another common side effect of viral infections.

How to Use Lemon Balm

You might have guessed that making tea from fresh or dried lemon balm is one of the best ways to use this herb when you’re sick. Learn how to make lemon balm tea here.

9. Cayenne Pepper – Warming Circulation Booster

By far one of the most useful herbs out there, cayenne pepper can be used for a variety of ailments to both heal illness and alleviate symptoms.

It has been used historically in the Caribbean and Latin America for febrile illnesses, including the deadly yellow fever, with good results.¹ When taken internally, cayenne pepper induces sweating, which reduces a fever and expels toxins from the body. This helps the body clear itself of invading pathogens—speeding recovery.

Cayenne pepper is also an excellent circulation stimulator, delivering immune cells, nutrients, and oxygen to where they are needed. This supports the immune system by moving white blood cells to areas of infection faster, promoting recovery.

Furthermore, its antimicrobial properties help knock out various infections while helping ease the symptoms. Studies have shown that capsaicin, the compound that’s responsible for cayenne’s heat, inhibits the growth of certain bacteria, fungi, and viruses. It’s been found to be particularly effective against the more antibiotic-resistant gram-negative bacterial strains.² Drinking cayenne pepper in a warm tea also helps loosen phlegm and clear mucous. It’s a good way to relieve sinus congestion and clear the airways to make breathing easier.

How to Use Cayenne Pepper

My favourite way to take cayenne pepper is in a honey lemon tea as follows:

Add 1/4 – 1 tsp of cayenne pepper to a mug of boiling water with the juice of half a lemon and honey to taste. Drink warm for best results.

10. Chickweed – A Nourishing Tonic for Recovery

If you’ve never heard of this one, you might be scratching your head. Chickweed—yes, chickweed, that pesky garden weed—is a fabulous herbal treatment for coughs and colds. It contains mucilage, a gelatinous substance, that coats any tissues it comes in contact with, making it soothing to sore throats and dry coughs. Chickweed also has expectorant properties, which help loosen and expel phlegm from the airways. In cases of bronchitis, chickweed promotes lymphatic drainage, which helps remove toxins from the body.

How to Use Chickweed

Chickweed can be used on its own or with other herbs to maximize its effects. Try combining it with mullein to treat coughs and respiratory infections, or with catnip to combat the flu.

Learn how to make a healing chickweed tea here.

Staying Healthy Naturally This Flu Season

Having an arsenal of natural, immune-supporting herbs in your home medicine cabinet can help you face cold and flu season with confidence. These powerhouse botanicals are virus-fighting, health-promoting allies that support your body’s natural defences and help you recover faster. From soothing herbs like chickweed and licorice that ease symptoms to immune boosters such as echinacea and yarrow that strengthen resistance, these time-tested herbal remedies can help you stay healthy and strong all season long.

1. Kloss, J. (2004). Back To Eden: The Classic Guide to Herbal Medicine, Natural Foods, and Home Remedies since 1939 (2nd ed., pp. 106-115). Lotus Press. ↩︎
2. Periferakis AT, Periferakis A, Periferakis K, Caruntu A, Badarau IA, Savulescu-Fiedler I, Scheau C, Caruntu C. Antimicrobial Properties of Capsaicin: Available Data and Future Research Perspectives. Nutrients. 2023 Sep 22;15(19):4097. doi: 10.3390/nu15194097. PMID: 37836381; PMCID: PMC10574431. ↩︎