The Best Herbs to Support Your Immune System this Cold & Flu Season
Written by Juliet Blankespoor and Meghan Gemma
Photography by Juliet Blankespoor
Winter is rife with viral booby-traps—there’s a head cold and cough waiting at every gas station pump and pin pad across the land. A robust immune system is adept at navigating pathogenic obstacles, but some scenarios call for a boost, herbal-style. When I know I’ve been exposed to a cold or the flu, I don’t waste a moment in reaching for my tried-and-true herbs to support the immune system.
Herbal immune stimulants support our immune system in fighting infection.
Immune stimulants—also called immunostimulants—help the body resist illness after exposure to a pathogen and during the initial stages of an infection. Immunostimulants augment our bodies’ innate antimicrobial efforts, primarily by affecting white blood cell activity. Antimicrobial herbs are often taken alongside immune-stimulating herbs because they fight microbial infection directly.
This class of herbs can also be called on to stimulate immune activity throughout the duration of an infectious illness, which can ultimately help a person get over the sickness more quickly. Contrary to popular belief, these are not herbs we take daily to support wellness. In contrast to immune stimulants (taken for a few weeks tops), daily immune remedies are called immune tonics and immunomodulators. Learning the different classes of immune herbs is essential for every herbalist!
Over the years, I’ve seen where and when immune stimulants are warranted to seriously hype up the immune system. These are situations where my family or I are exposed to a high level of pathogens, often in stressful situations (and stress is known to dampen the immune response).
When herbal immunostimulants are a good idea:
- Flying on an airplane
- Caring for a sick family member
- Attending a four-year-old’s birthday party in January
- Feeling the first signs of a cold
- Fighting an infectious illness, like a cold or the flu
- The first few weeks of back-to-school
- Attending holiday gatherings
- Going to see any Pixar movie
Immunostimulating herbs have an immediate but short-lived effect, and thus need to be re-administered frequently to maintain their effectiveness. In my experience, higher doses of these herbs are often needed to treat infection. If you have an autoimmune condition, please be aware that immune-stimulating herbs have the potential to increase autoimmunity, although this is more the exception than the rule. This is something I have seen only rarely, but it does occur.
Foundational self-care is even more essential than taking immune-stimulating herbs.
Remember, herbs are handy allies, but it’s all too easy to “prop ourselves up” with immune stimulants while we continue to neglect the care of our body, emotions, or spirit. If we consistently ignore the basics of good sleep, nutrition, hydration, and lifestyle, we have missed the point.
See our in-depth article on Herbs for the Immune System for basic tips on staying healthy this winter. You’ll also find loads of essential information on the full spectrum of immune-boosting herbs, including immune tonics and herbal antimicrobials!
Get to know each immune remedy intimately, and be sure of your identification!
Please note that this article is introductory in scope and doesn’t fully cover each medicinal. If you plan to forage any of these herbs, you’ll need to seek out identification tips. You’ll also need to learn foraging ethics and receive guidance before you harvest any plant from the wild! There are deadly poisonous plants out there, so proper identification is paramount. See our blog articles on Foraging and Wildcrafting and our 10 Essentials of Herbal Safety Guide for more guidance.
Safety First: Learn When to Seek Medical Care
Also, it’s important to realize that herbs aren’t always the only support you might need to combat infections. Antibiotics and conventional medical care have their place, especially with babies, young children, and elders, as well as in the case of serious infections. For a list of warning signs that indicate the need for medical care, please visit our comprehensive article on Herbs for the Immune System.
Top 5 Herbs for Boosting the Immune System:
- Spilanthes, Toothache Plant, or Paracress (Acmella oleracea, Asteraceae)
- Echinacea (Echinacea purpurea; E. angustifolia, Asteraceae)
- Japanese Honeysuckle (Lonicera japonica, Caprifoliaceae)
- Prickly Ash, Toothache Tree, or Hercules’ Club (Zanthoxylum clava-herculis, Z. americanum, Rutaceae)
- Garlic (Allium sativum, Amaryllidaceae)

Spilanthes (Acmella oleracea) is the first immune stimulating herb I reach for.
1. Spilanthes, Toothache Plant, or Paracress (Acmella oleracea, Asteraceae)
Parts Used: Leaves, stems, and flowers
Preparations: Tincture, tea, nibble
Herbal Actions:
- Immunostimulant
- Antimicrobial
- Anti-inflammatory
- Sialagogue (stimulates salivation)
Spilanthes has been one of my top ten herbal allies for the past two decades—I became a devotee the first year I began growing it and using it for medicine. Its leaves and gumdrop-shaped flowers can be called upon for a wide spectrum of infectious illnesses; including colds, flu, sinus infections, and ear infections. Clinical studies demonstrate that spilanthes has strong effects against pathogenic bacteria.
One of the most common ways I use spilanthes is to augment the body’s internal immune defenses. I typically combine it with other immune-stimulating herbs like echinacea (Echinacea purpurea) and honeysuckle (Lonicera japonica). At the first sign of an achy throat or the sniffles, I add spilanthes to homemade saline gargles and neti pot solutions, along with goldenseal (Hydrastis canadensis).
Remember that higher doses—to the tune of 3 to 4 droppersful of the tincture every few hours for the first day or two—are often necessary to fight infection and avoid antibiotic use. If an infection does take hold, I add other antimicrobial herbs like usnea (Usnea spp.), goldenseal (Hydrastis canadensis), and honeysuckle (Lonicera japonica) to the formula.
Be forewarned that the tincture and fresh plant will set your mouth to drool! Spilanthes is a traditional toothache remedy because of its antimicrobial, numbing, and stimulating qualities. Along with the stimulation of blood to the gums, the herb will also prompt copious salivation.

Echinacea (Echinacea purpurea) is one of the easiest-to-grow immune herbs.
2. Echinacea (Echinacea purpurea; E. angustifolia, Asteraceae)
Parts Used: Roots, flowering tops, aboveground parts gathered in full bloom
Preparations: Tincture, decoction (roots), infusion (leaves and flowers)
Herbal Actions:
- Immunostimulant
- Antimicrobial
- Anti-inflammatory
- Anticatarrhal (decongestant)
- Lymphagogue
- Sialagogue (stimulates salivation)
- Alterative
The roots, seeds and fresh flowers of echinacea are all medicinal and make a tingly tasting, immune-stimulating tea or tincture. Echinacea can be used to fight any infection in the body, but is particularly effective against infections of the upper respiratory tract. I use it as a short-term remedy for warding off colds and flu. Studies show that echinacea is safe and effective against the common cold and that it is protective against lowered immunity due to stress.
Herbalist Rosemary Gladstar reminds us that echinacea is both “preventative and curative.”1 Unfortunately, many people stop taking it once they are sick, thinking it can’t help them anymore. However, echinacea stimulates many aspects of our immune system to fight infection more quickly and continues to be an important ally even once we become ill. I often combine it with spilanthes (Acmella oleracea) to round out its immunostimulating qualities.

Echinacea purpurea growing at Gaia Herb Farm in Brevard, NC.
Echinacea is readily available anywhere herbal teas and tinctures are sold. Please only buy the cultivated root, as several echinacea species have been over-harvested from the wild. If you make your own medicines, I recommend using freshly harvested echinacea from the garden rather than dried, as I find the fresh preparations to be more potent. I like to combine the root tincture with the seed tincture in equal parts.

Japanese honeysuckle (Lonicera japonica) is both antimicrobial and immune stimulating.
3. Japanese Honeysuckle (Lonicera japonica, Caprifoliaceae)
Parts Used: Floral buds, opened flowers, stems, and leaves
Preparations: Tincture, decoction, infusion, honey, syrup, poultice, douche, and compress
Herbal Actions:
- Immunostimulant
- Antiviral
- Antibacterial
- Anticatarrhal (decongestant)
- Expectorant
- Anti-inflammatory
- Astringent
- Diuretic
- Antioxidant
I use Japanese honeysuckle flowers to address hot, inflamed conditions like head colds and the flu, as well as a range of related infections—laryngitis, sinusitis, tonsillitis, pneumonia, bronchitis, croup, and whooping cough. The fresh blooms are powerfully antimicrobial, cooling, and anti-inflammatory—making them specific for malaise and feverish conditions.
I’ve been using the flowers medicinally for over thirty-five years and continue to be impressed by their efficacy.
They are one of the most widely used medicinal herbs in the world, especially in China, where the herb is decidedly popular, both with trained herbalists and as an over-the-counter herbal medicine. Japanese honeysuckle’s popularity amongst Western herbalists primarily comes from being inspired by traditional Chinese herbalists.
For a scientific review of Japanese honeysuckle’s antimicrobial benefits, visit this link.
Japanese honeysuckle is a common invasive plant in eastern and central North America. Still, you won’t find its medicine readily available in commerce except in establishments selling Chinese medicine or perhaps in a local apothecary specializing in bioregional herbs.

Japanese Honeysuckle blooms (Lonicera japonica)
Harvesting your own honeysuckle flowers is easy and pleasurable as long as you are sure of your identification. The flowers can be gathered both as buds and as opened blooms and tinctured fresh in alcohol. In Chinese medicine, the buds are considered the most potent, but I find the buds and the freshly opened flowers to be similar medicinally. Honeysuckle is also effective as a tea; try combining it with lime blossom (Tilia spp.) and lemon verbena (Aloysia citrodora) to improve its flavor.
Though many honeysuckle species have been used medicinally across North America, Europe, and Asia, their uses—and the parts employed—vary. The biochemistry of the genus is also diverse; for example, some species have poisonous berries, and others have leaves or bark that may cause extreme digestive distress.
Therefore, it’s important not to generalize the medicinal qualities of all honeysuckles. This article focuses solely on Japanese honeysuckle, so don’t apply this information to other species! See our links for identification tips at the bottom of this plant profile, and remember that Japanese honeysuckle is a woody vine and not a shrub!
Japanese honeysuckle is native to eastern Asia but is invasive in much of the world. Do not plant Japanese honeysuckle as it’s seriously invasive. Harvesting it for medicine is one way to slow its spread!
Here are some resources to help you properly identify Japanese honeysuckle:

Prickly Ash (Zanthoxylum clava-herculis, Z. americanum) was once widely used as an immune stimulant, but is lesser known today.
4. Prickly Ash, Toothache Tree, or Hercules’ Club (Zanthoxylum clava-herculis, Z. americanum, Rutaceae)
Parts Used: Bark and berries
Preparations: Tincture, decoction
Herbal Actions:
- Immunostimulant
- Lymphagogue
- Antimicrobial
- Diaphoretic
- Circulatory stimulant
- Sialagogue (stimulates salivation)
- Antirheumatic
- Astringent
- Antibacterial
- Antiprotozoal
Prickly ash may be less familiar to you than the other herbs featured in this article, yet it’s one of our finest lymphatic herbs, immune stimulants, and circulatory stimulants.
Prickly ash’s name is derived from its leaf arrangement bearing a loose resemblance to the unrelated ash tree (Fraxinus spp.) and its formidable thorns, found along its branches and trunk. The tree’s fearsome armament inspired its alternate name, Hercules’ club. (Note: the common name Hercules’ club is also used for the unrelated Aralia spinosa.)
When I was in college one of my botany professors pulled a prank on me in front of my classmates. He invited us to try some of the tree’s fruits, and being an adventurous fledgling herbalist, I gamely chewed on a handful.
Immediately, my mouth became tingly and numb. I began drooling, bent over in an attractive spit-hunch to release the flood of saliva upon the ground. That experience was an unforgettable introduction into the profound physiological effect of alkamides, immune-stimulating and saliva-inducing compounds that are also shared by echinacea and spilanthes. This distinct mouth-numbing quality prompted yet another common name— toothache tree.
Prickly ash’s yellow bark played prominently into the materia medica of Native Americans and subsequently the European settlers, due to its wide medicinal applications, including powerful antimicrobial qualities. The bark is colored yellow by a potent antimicrobial alkaloid, berberine, which is also found in goldenseal (Hydrastis canadensis), barberry (Berberis, multiple species) and Oregon grape root (Mahonia, multiple species).
The tea and tincture of the bark are used in a similar fashion. Be warned that the tea is tingly and strong tasting. Many herbalists put a small amount of prickly ash in their herbal combinations as an adjuvant—an herb that directs, or orchestrates, the actions of the other herbs in a formula. Think: botanical rabble-rouser.

Prickly Ash (Zanthoxylum clava-herculis, Z. americanum).
Prickly ash bark is taken in small amounts tonically to move the lymphatic system, innervate the immune system and stimulate circulation. In larger amounts, it is used to treat varied acute digestive issues, and is especially helpful in treating transient, foodborne gastric infections.
Toothache tree can be used to numb the gums in dental infections, and also offers antibacterial assistance. The bark can be used topically—chew on twigs or brush with the powder daily to improve gum health in periodontal disease. Toothache tree’s oral benefits stem from increased circulation and tightening loose gums, as well as its antimicrobial qualities.
Various species in the Zanthoxylum genus produce spicy fruits called Szechuan pepper, a pungent spice used in Asian cuisine, notably Chinese five-spice powder. Many other species are used medicinally in India, China, Korea and Japan. Both Z. americanum and Z. clava-herculis are considered interchangeable medicinally.

A handful of garlic (Allium sativum), one of the finest kitchen herbs for boosting immunity.
5. Garlic (Allium sativum, Amaryllidaceae)
Parts Used: Bulb
Preparations: Raw, tincture, fire cider and other infused vinegars, honey, oil
Herbal Actions:
- Immunostimulant
- Immune tonic
- Antimicrobial
- Diaphoretic
- Hypotensive (lowers blood pressure)
Herbalist David Hoffman writes that: “Used daily, garlic aids and supports the body in ways that no other herb can match.”2 Among its many gifts, garlic is one of our finest remedies for supporting immune health—it’s an essential staple in my kitchen as a potent immune stimulant and antimicrobial herb (it both kills pathogens and boosts immunity).
It can be highly effective in preventing infections such as the common cold and flu, as well as combating pathogens if an illness takes hold. Clinical studies support the ancient folk wisdom that garlic does indeed activate the immune system.
Pungent and warming, garlic helps to break up mucus in the body; it’s specifically beneficial for respiratory congestion. Raw garlic is the most effective preparation for avoiding and treating acute infections. Crush or chop a clove and allow it to “wilt” by leaving it alone on the cutting board for 10-15 minutes. Then add to honey, oil*, soup, vinegar, or tea.

Garlic scapes (Allium sativum).
Garlic is metabolized via the bloodstream, so applying garlic oil to the bottoms of the feet is an effective way to get its medicine flowing through the body (an especially great application for kiddos!).
Garlic doubles as an immune tonic, which means that it can be taken regularly to bolster the immune system over time. One clove per day, minced and added to food raw, is optimal.
My favorite garlicky preparation is fire cider—a sweet and spicy tonic made with apple cider vinegar. I recommend trying our rich red recipe for Hibiscus Pomegranate Fire Cider. I like spooning it over salads, and always take a tablespoon or two when I feel a sore throat or runny nose coming on. Also, check out my Homemade Medicinal Garlic Sauce, one of my students’ favorite recipes from our online programs. It is also responsible for keeping our family healthy throughout the cold and flu season.
References
- Gladstar R. Rosemary Gladstar’s Herbal Recipes for Vibrant Health: 175 Teas, Tonics, Oils, Salves, Tinctures, and Other Natural Remedies for the Entire Family. Storey Pub.; 2008.
- Hoffmann D, FNIMH, AHG. Medical Herbalism: The Science and Practice of Herbal Medicine. Inner Traditions / Bear & Co; 2003.
Looking for more blog articles on herbs for the immune system? We’ve compiled our most comprehensive free herbal resources on the subject, and they’re all right here for your convenience.

JULIET BLANKESPOOR is the founder, primary instructor, and Creative Director of the Chestnut School of Herbal Medicine, an online school serving thousands of students from around the globe. She's a professional plant-human matchmaker and bonafide plant geek, with a degree in botany and over 30 years of experience teaching and writing about herbalism, medicine making, and organic herb cultivation. Juliet’s lifelong captivation with medicinal weeds and herb gardening has birthed many botanical enterprises over the decades, including an herbal nursery and a farm-to-apothecary herbal products business.
These days, she channels her botanical obsession through her writing and photography in her online programs, on her personal blog Castanea, and in her new book, The Healing Garden: Cultivating and Handcrafting Herbal Remedies. Juliet and her family reside in a home overrun with houseplants and books in Asheville, North Carolina.

MEGHAN GEMMA is one of Chestnut School of Herbal Medicine's primary instructors through her written lessons, sharing herbal and wild foods wisdom from the flowery heart of the school to an ever-wider field of herbalists, gardeners, healers, and plant lovers.
She began her journey with the Chestnut School in 2010—as an intern and manager at the Chestnut Herb Nursery and then as a plant-smitten student “back in the day” when the school’s programs were taught in the field, and later she became part of the school’s writing team. Meghan lives in the Ivy Creek watershed, just north of Asheville, North Carolina.
Interested in becoming a contributor?
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Dr. Farah Saeed says:
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Joe Maxwell says:
I’m sorry, but this information and the wording of the title are simply incomprehensible to me. WHY (!) would you want to “stimulate” the immune system against cold and flu viruses? With notable exceptions (SARS and MERS), cold and flu viruses do very little damage to human tissue. It is rather the body’s OVER-REACTIVE response to these viruses in many people that cause the severest of damage, and in some cases an even potentially fatal cytokine storm.
Sarah Sorci says:
We appreciate this dialogue, Joe! As mentioned in this article, there are some instances where immune stimulants might be contraindicated or at least should be used more cautiously (like with autoimmunity). But for most healthy people, immune-stimulating herbs can help to shorten the duration of a cold or flu and shouldn’t be concerning. We haven’t seen any documented cases of immune-stimulating herbs causing a cytokine storm, but we’re always happy to incorporate new science-based information into our articles.
To go a little deeper into your question, immune-supportive compounds have been part of traditional diets and lifestyles around the world for hundreds or thousands of years. Some argue that the removal of this diverse array of phytochemicals from the modern diet may be partly responsible for autoimmune conditions, allergies, and other overactive immune responses that we see. Guido Mase has an excellent book that explores this topic, and he shares some relevant research that’s been done: The Wild Medicine Solution.
You might be interested in our Introduction to Immune Stimulants, Immunomodulators, and Antimicrobials article on Blog Castanea. The polysaccharides found in medicinal mushrooms and other immunomodulating herbs and wild foods are a big topic in Mase’s book.