Herbal Remedies for Immune Support
Astragalus, elderberry and echinacea are the herbs I reach for most when someone tells me they catch every cold that comes through their house. Each has a long record of traditional use, and each has been tested in at least some human trials, with results that range from encouraging to mixed. This article covers what the traditions claimed, what the trials found, how I prepare each herb at home in Montana, the vitamins and minerals that sit underneath all of it, and who should leave these herbs alone.
Key takeaways
- Astragalus is a tonic taken over weeks. Chinese texts stop it once a cold is underway.
- Elderberry has small positive trials and one larger negative one. Cook the berries and never eat them raw. For a child under one year, sweeten the syrup with maple syrup or sugar instead of honey.
- Pooled echinacea trials show a small reduction in cold frequency, and the result depends heavily on which product was tested.
- Vitamin C, zinc and vitamin D each have independent trial evidence behind them, and none of the herbs above does much for a person who is short on them.
- The only dose figure here is for astragalus, attributed to Bensky. Everything else is given as a preparation form or a food source.
- Anyone taking immunosuppressant medication or living with an autoimmune diagnosis should talk to their prescriber before using any of the three herbs.
I am a certified clinical herbalist, not a physician. This article describes traditional use and published research. It is educational and does not diagnose, treat or prevent any disease. Speak with your own practitioner before adding herbs to your routine, especially if you take medication, are pregnant, or manage a chronic condition.
What herbalists mean by immune support
Evidence: framing, not a clinical claim.
In Traditional Chinese Medicine the relevant idea is wei qi, the defensive qi said to circulate at the body's surface and hold off external pathogens. Western herbalism divides the same territory differently. Some herbs are tonics, the ones sold as immune strengthening herbs, taken daily over a season by people who get sick often. Others are taken at the first scratch in the throat and dropped once the illness passes. The two groups are not interchangeable, and most of the confusion I see comes from using a tonic as an acute remedy or the reverse.
None of these herbs replaces sleep, enough protein, vitamin D through a northern winter, or time outdoors. They sit on top of those things, and the nutrient section further down covers the part herbalists tend to skip.
Astragalus root (Huang Qi)
Evidence: traditional use strong. Human clinical data limited.
Astragalus mongholicus, still listed in many texts as A. membranaceus, is one of the most used tonic roots in Chinese medicine. Bensky's materia medica places it in the lung and spleen channels, where it tonifies qi and stabilizes the exterior.1 The classic picture is a person who sweats without exertion and catches whatever is going around. The same texts carry a caution that matters in practice: astragalus is not given during an exterior excess condition, meaning an active cold with fever or chills, because tonifying at that stage is said to hold the pathogen in.
Modern research has focused on the root's polysaccharides and astragalosides. Cell and animal studies report effects on macrophage and natural killer cell activity, and Block and Mead's 2003 review summarizes that work alongside echinacea and ginseng.2 Human trials are small, and many exist only in Chinese-language journals, so I rate the clinical tier as limited rather than moderate. The traditional case is far stronger than the trial case.
How I prepare it
Sliced dried root is decocted, which means simmered rather than steeped. Bensky gives 9 to 30 g of dried root per day in decoction.1 I keep a bag of the flat, tongue-shaped slices in the pantry and drop 4 slices into a pot of bone broth for the last 40 minutes of cooking, then fish them out before serving. The taste is mild and faintly sweet, and no one at the table notices it is there.
Elderberry (Sambucus nigra)
Evidence: moderate, with a mixed trial record.
European folk medicine cooked the berries into syrups and cordials for colds, and steeped the flowers as a sweat-inducing tea for fevers. Blue elderberry, Sambucus nigra ssp. cerulea, grows along creeks across western Montana and ripens in late August. I gather it every year, and it is the one herb in this article I never have to buy.
The trial record is the most interesting part. In 2004, Zakay-Rones and colleagues gave elderberry syrup to 60 adults with confirmed influenza and reported symptom relief about four days earlier than placebo, in a trial paid for by the manufacturer of the syrup.3 In 2016, Tiralongo's team followed 312 economy-class air travelers taking elderberry extract capsules, and those who caught a cold had it for fewer days and rated it milder.4 A 2019 meta-analysis pooled 4 randomized trials covering 180 people and found shorter symptom duration.5 Then in 2020, Macknin and colleagues ran the largest independent trial to date, 87 emergency room patients with influenza, and found no difference from placebo at all.6 The early trials were small and mostly industry-funded, and the largest independent one was negative, so I treat elderberry as promising rather than proven.
How I prepare it
Strip the berries from the stems, cover with water, and simmer 20 minutes before straining and sweetening. Raw berries, leaves, stems and bark contain cyanogenic glycosides, and eating berries raw or undercooked causes nausea and vomiting. Cooking breaks those compounds down. I sweeten with honey for adults and older children, and with maple syrup or sugar when the syrup is for a child under one year.
Elderberry Syrup Recipe and Herbal Monograph
The syrup recipe with a cups and grams toggle, the poisonous look-alikes, why the berries must be cooked, contraindications, and the full trial record with funding labelled.
Echinacea (E. purpurea, E. angustifolia)
Evidence: moderate for a small preventive effect. Results vary widely by product.
Plains nations including the Lakota, Cheyenne and Kiowa chewed echinacea root for sore throat and toothache and applied it to bites and wounds. Eclectic physicians took it up in the 1880s, and by the turn of the century it was the most prescribed botanical in that school. The full traditional and clinical record is in my echinacea monograph, so this section stays on the immune question.
The 2014 Cochrane review is the reference point. Karsch-Völk and colleagues examined 24 double-blind trials with 4,631 participants. No single trial showed a significant preventive effect, but the pooled data pointed to a reduction in cold incidence of 10 to 20 percent, and the authors judged that the products tested were too different from one another to treat as one intervention.7 Shah's 2007 meta-analysis reported larger numbers, a 58 percent drop in odds and 1.4 fewer days of illness, and was criticized for pooling unlike studies.8 Between the two, a small effect is the fair reading.
The product question is not a footnote. Trials have used E. purpurea aerial parts, E. angustifolia root, pressed juice, alcohol tinctures and dried extracts, and these are not the same medicine. When I recommend echinacea I name the species and the plant part, and I use it at onset rather than daily through a season.
How I prepare it
In my own kitchen it is a tincture. I keep a bottle of echinacea root tincture and, at the first scratch in the throat, add two dropperfuls to a glass of water. That is a description of what I do, not a dose recommendation for anyone else. I use a tincture rather than dried root because I reach for echinacea only when a cold is starting, which is not often, and a tincture keeps for years on the shelf while dried root loses its tingle within a year or two. That way I never have to keep a rotating supply of fresh root on hand for something I use so rarely. The root, fresh or tinctured, should tingle on the tongue. The tingling comes from alkylamides, and its absence in a product tells you something about how it was made.
Types of Herbal Preparations
Why astragalus is decocted, elderberry is made into syrup and echinacea into tincture, plus glycerites, oxymels, oils and salves, with shelf life for each.
How I use them across a cold season
Evidence: clinical practice, not trial data.
From October onward, astragalus goes into broth or a decoction 3 to 4 times a week. That continues until the first sign of illness, at which point it stops, following the Chinese caution about tonifying during an exterior condition. Echinacea tincture and elderberry syrup take over for the first days of a cold. Once the fever has gone and the worst is past, astragalus comes back. Nothing in this rhythm is a treatment claim. It is the sequence traditional practice suggests and the one I follow at home.
Immune support tea: what goes in it and how to make it
Evidence: preparation method, not a clinical claim.
Most immunity tea sold in a box is echinacea and elderberry with ginger, lemon peel or hibiscus for flavor. Those blends steep in a mug for five minutes, which works for the flowers and leaves but wastes the roots. Astragalus root and echinacea root need 20 to 30 minutes at a simmer to extract their polysaccharides, and elderberries need to be cooked anyway. At home I make the roots as a decoction in a saucepan and add the soft ingredients, elderflower, lemon balm or peppermint, for the last five minutes with the heat off. An elderberry and echinacea tea made this way tastes tart and earthy and takes honey well.
The herbal tea blends in my shop are built on these plants, and each product note tells you which ones need simmering and which can steep.
Vitamins, minerals and water
Evidence: moderate for vitamin C, zinc and vitamin D, from independent pooled trials. Hydration rests on physiology and tradition, not trials.
No herb in this article does much for a person who is short on the nutrients the immune system runs on. I would rather a client addressed these first and then looked at herbal support second.
Vitamin C
The Cochrane review by Hemilä and Chalker pooled 29 trials with 11,306 participants. Regular vitamin C did not reduce how often the general population caught colds, but it shortened them modestly, by about 8 percent in adults and 14 percent in children, and in people under heavy physical stress such as marathon runners, skiers and soldiers on winter exercise it cut the number of colds in half.10 Taking it only after a cold had started showed no consistent benefit. Wild rose hips grow on the same creek banks as the elderberry here and are the richest food source I know of. Bell peppers, citrus, raw sauerkraut and potatoes cover it the rest of the year.
Zinc
Hemilä's 2017 analysis pooled three trials of zinc acetate lozenges and found colds ended about a third sooner when the lozenges were started within the first day.11 The form and the timing both mattered, and the lozenge has to dissolve in the mouth rather than be swallowed. For daily intake I point people to food before supplements. Oysters, beef, lamb and liver carry zinc in a form the body absorbs well. Pumpkin seeds and legumes carry it alongside phytates that block much of it.
Vitamin D
Martineau and colleagues reanalyzed individual data from 25 trials and 11,321 participants in the BMJ in 2017 and found that daily or weekly vitamin D reduced the risk of acute respiratory infection, with the largest effect in people who started out deficient.12 In Montana the sun sits too low from November through February for skin to make any, and the same is true across the northern half of the country. Cod liver oil, egg yolks, fatty fish and liver are the food sources. Whether to supplement, and how much, is a conversation for your practitioner and a blood test, not an article.
Water
The lining of the nose and throat is the first barrier a virus meets, and it works only while it is moist. Heated indoor air and altitude dry it out, and both apply for most of us through winter. No trial has tested hydration against colds, so this rests on physiology and on every tradition I have trained in, all of which advocate giving a sick person some warm fluids. The astragalus broth from earlier in this article covers two of these needs in one go.
Who should not use these herbs
Evidence: safety literature and traditional cautions, labelled where they differ.
This section, like the rest of the article, is for educational purposes and is not medical advice. It cannot account for your health history or your medications, and it is not a substitute for a conversation with your own practitioner.
- Immunosuppressant medication. Transplant drugs, biologics and similar prescriptions are designed to lower immune activity. All three herbs have been studied for raising it in cell and animal work. A prescriber conversation comes before any use.
- Autoimmune diagnosis. Textbook cautions against echinacea and astragalus in autoimmune disease are precautionary and rest on mechanism rather than on documented harm in trials. I still follow them.
- Asteraceae allergy. Echinacea is in the daisy family. Anyone who reacts to ragweed, chamomile or chrysanthemum should skip it.
- Raw elderberry. Berries, leaves, stems and bark contain cyanogenic glycosides. Cook the berries, discard everything else.
- Children. A 2003 randomized trial of 407 children aged 2 to 11 found echinacea no better than placebo for cold symptoms and associated with more rash.9 Cooked elderberry syrup is widely given to children. For a child under one year, sweeten it with maple syrup or sugar rather than honey.
- Pregnancy. Safety data for all three are thin. Astragalus appears in some classical Chinese formulas used during pregnancy, but that is a prescribed context and not a reason to self-select it.
Frequently asked questions
Which herb is best for immune support?
It depends on timing. Astragalus is taken over a season by people who get sick often. Echinacea and elderberry are taken at the first sign of a cold and stopped when it passes.
Who should not take echinacea?
Anyone allergic to plants in the daisy family, anyone on immunosuppressant medication, and anyone with an autoimmune diagnosis unless a prescriber has cleared it. A 2003 trial found no benefit in children aged 2 to 11 and more rash, so I do not recommend it for that age group.
Who should not take astragalus?
Chinese texts stop it during an active cold with fever or chills. The same cautions as echinacea apply for immunosuppressant medication and autoimmune disease, and there is not enough safety data to self-select it in pregnancy.
What is the best time of day to take astragalus?
No trial has tested time of day. Traditional decoctions are drunk warm in divided doses through the day, and because astragalus is a tonic, taking it consistently matters far more than the hour.
Can I take astragalus and echinacea together?
Herbalists usually do not combine them, because astragalus is paused during an acute cold while echinacea is used only during one. They belong to different windows in the season.
Can you take elderberry and echinacea together?
Yes. Both are onset herbs and are commonly combined in syrups and teas at the start of a cold. No interaction between the two has been reported. The daisy-family allergy caution for echinacea still applies.
Is elderberry safe for kids?
Cooked elderberry syrup is widely given to children. Never give raw berries, and for a child under one year use maple syrup or sugar in place of honey. The one trial that included children, from age 5 upward, found no benefit over placebo, so treat it as a traditional remedy rather than a proven one.
Can you take elderberry while pregnant?
Cooked elderberries eaten as food have a long history. Concentrated extracts and daily syrup have no pregnancy safety trials behind them, so ask your midwife or practitioner before using them.
Do vitamin C and zinc work for colds?
Pooled trials show regular vitamin C shortens colds modestly and zinc acetate lozenges started on the first day shorten them by about a third. Neither has been shown to stop a cold from starting in the general population.
Sources
- Bensky D, Clavey S, Stöger E. Chinese Herbal Medicine: Materia Medica, 3rd ed. Eastland Press, 2004. Huang Qi entry. ↩
- Block KI, Mead MN. Immune system effects of echinacea, ginseng, and astragalus: a review. Integrative Cancer Therapies. 2003;2(3):247-267. doi:10.1177/1534735403256419 ↩
- Zakay-Rones Z, Thom E, Wollan T, Wadstein J. Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infections. Journal of International Medical Research. 2004;32(2):132-140. doi:10.1177/147323000403200205. Manufacturer-funded. ↩
- Tiralongo E, Wee SS, Lea RA. Elderberry supplementation reduces cold duration and symptoms in air-travellers: a randomized, double-blind placebo-controlled clinical trial. Nutrients. 2016;8(4):182. doi:10.3390/nu8040182 ↩
- Hawkins J, Baker C, Cherry L, Dunne E. Black elderberry (Sambucus nigra) supplementation effectively treats upper respiratory symptoms: a meta-analysis of randomized, controlled clinical trials. Complementary Therapies in Medicine. 2019;42:361-365. doi:10.1016/j.ctim.2018.12.004 ↩
- Macknin M, Wolski K, Negrey J, Mace S. Elderberry extract outpatient influenza treatment for emergency room patients ages 5 and above: a randomized, double-blind, placebo-controlled trial. Journal of General Internal Medicine. 2020;35(11):3271-3277. doi:10.1007/s11606-020-06170-w ↩
- Karsch-Völk M, Barrett B, Kiefer D, Bauer R, Ardjomand-Woelkart K, Linde K. Echinacea for preventing and treating the common cold. Cochrane Database of Systematic Reviews. 2014;(2):CD000530. doi:10.1002/14651858.CD000530.pub3 ↩
- Shah SA, Sander S, White CM, Rinaldi M, Coleman CI. Evaluation of echinacea for the prevention and treatment of the common cold: a meta-analysis. Lancet Infectious Diseases. 2007;7(7):473-480. doi:10.1016/S1473-3099(07)70160-3 ↩
- Taylor JA, Weber W, Standish L, et al. Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial. JAMA. 2003;290(21):2824-2830. doi:10.1001/jama.290.21.2824 ↩
- Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database of Systematic Reviews. 2013;(1):CD000980. doi:10.1002/14651858.CD000980.pub4 ↩
- Hemilä H. Zinc lozenges and the common cold: a meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage. JRSM Open. 2017;8(5):2054270417694291. doi:10.1177/2054270417694291 ↩
- Martineau AR, Jolliffe DA, Hooper RL, et al. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ. 2017;356:i6583. doi:10.1136/bmj.i6583 ↩
