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An ancient remedy for fatigue and depressed immunity

Astragalus

Astragalus membranaceus Fabaceae

Astragalus root is one of the leading traditional tonic remedies from China, particularly helpful cases of lowered immunity associated with fatigue.

  • How does it feel?

    Astragalus root has a sweet, slightly sour taste, like some exotic fruit, ending with a distinctly soapy sweet aftertaste.

    The sweetness of astragalus is due to both its prominent polysaccharide (complex sugar) and saponin content; the aftertaste reminds us that ‘saponin’ derives from the Latin for soap. Astragalus also lathers when shaken in water, a quality that the ancients were wise to take seriously.

  • What can I use it for?

    If you are prone to repeated colds or other viral infections or otherwise have impaired immune defences, then taking astragalus root regularly over several months has been found to improve resilience. The value of astragalus is likely to be greater if you have had blood tests that show low white blood cell counts.

    It may add further benefits if there is an allergic quality to the respiratory problems, for example they are worse in spring and summer, or when mould counts are high, in damp autumn and winter seasons.

    The symptoms above are often combined with low energies, and astragalus was a traditional remedy for chronic fatigue states. This is especially appropriate when the fatigue is judged to be ‘post-viral’ and or when it is linked to reduced appetite. Astragalus is the first-choice herb for fatigue treatment in traditional Chinese medicine.

    It is also the main herb used in hospitals for stroke recovery in China and Taiwan. As well as reinforcing its role in building resilience this points to a benefit for a wide range of circulatory problems. It can provide safe background support for other treatments for heart symptoms and circulatory problems where these are exacerbated by fatigue and low energies.

    For the optimum benefit it is probably better to look out for a dried root powder supplement, and use only liquid forms that have been carefully prepared to extract both the polysaccharides and the saponins.

  • Into the heart of Astragalus

    Astragalus is traditionally highly regarded as a tonic remedy. In the language of Traditional Chinese Medicine it was seen to tonify both active energies (qi) and those that build resilience (xue or Blood), as well as supporting the Chinese concept of the Spleen (the function controlling assimilation in this body – thus being used where fatigue is linked to decreased appetite).

  • Traditional uses

    The root has been used for many hundreds of years in Traditional Chinese Medicine as a tonic in fatigue, especially with decreased appetite, spontaneous sweating and diarrhoea. Also to reduce blood loss and improve kidney function. and to recover from postpartum fever, organ prolapse, uterine bleeding and and other severe loss of blood.

  • Traditional actions

  • What practitioners say

    Respiratory: recurrent viral infections are probably the prime use of astragalus in modern practice.

    Circulation: use as a heart tonic in recovery from a wide range of cardiovascular problems as it will help steady the heart beat and improve cardiac performance. It is specific after viral endocarditis.

    Urinary: helpful in the aftermath of kidney disease by improving urine elimination and other kidney functions

    Metabolic and inflammatory: likely particularly to benefit chronic low-level inflammatory (especially viral) conditions associated with leucopenia and other evidence of compromised immunity. Also helpful in reducing inflammatory pressures in pre-diabetes or “metabolic syndrome’, where there is also high cholesterol and related markers.

    Reproductive system: astragalus traditional reputation could be harnessed to supporting women with heavy blood loss from periods; it was also used by midwives in China to help stop postpartum bleeding.

    Viral conditions: consider astragalus in supporting regimes recovering from a wide range of viral conditions like endocarditis, cervicitis or pneumonia.

  • Research

    Much of the clinical research literature until recently has been published in China, in Chinese, and relates often to the widespread medical practice there of prescribing astragalus extracts by intravenous injection. This mode of application avoids the digestive breakdown of polysaccharides and so delivers a remedy that is not comparable with traditional oral consumption. Other research literature applies to astragalus in combination with other ingredients.

    There is also a considerable research literature that refers to laboratory studies. The difficulty with this evidence is that two key groups of constituents will not reach the tissues unaffected by their transformation in the digestive system. Polysaccharides are unlikely to survive early stomach digestion at all and the saponins will be significantly changed, including by the action of the microbiome.

    The following are clinical trials and in vitro studies that refer whole plant extracts taken alone and by mouth or to specific astragalus compounds respectively.

    Immune system: In vitro studies have found that Astragalus markedly enhanced cytotoxicity of natural killer cells, and also potentiated interleukin 2 LAK (lymphokine- activated killer) generated cell cytotoxicity. In 9 out of 10 cancer patients astragalus restored T-cell function. Several studies have demonstrated astragalus polysaccharides immune enhancing activity in vitro, and have also confirmed their effectiveness for improving responses of lymphocytes in both normal subjects and cancer patients (5).

    Astragalus also has demonstrated numerous mechanisms by which it is effective as an anti-viral , largely as a result of its effects upon the immune system and by enhancing interferon production. These effects have also been demonstrated in clinical trials where a large number of subjects with chronic viral hepatitis had a success rate of 70%. In most cases elevated glutamic pyruvic transaminase levels were normalised within 1- 2 months (5).

    Nervous system: In a preliminary randomised controlled clinical trial among patients with post-stroke fatigue astragalus was found to improve fatigue scores in comparison with placebo. It improved cognitive functioning, social functioning, and global quality-of-life scores (1).

    Cardiovascular system: In a double-blind crossover clinical trial a supplement with an extract of astragalus was found to improve cholesterol balance and reduce TNF-α (a marker of inflammation) in patients with metabolic syndrome (a precursor to diabetes) (2). Benefits for heart function were also seen when astragalus was added to standard prescriptions in cases of postmenopausal women with metabolic syndrome (3). 

    A diuretic action has been observed in a small placebo-controlled study on healthy men, astragalus increased urinary sodium and chloride excretion during the first 4 hours although not at 12 hours. Test results indicated enhanced kidney responses to endogenous atrial natriuretic peptide. A key saponin astragaloside IV was ruled out as the active principle (4).

  • Did you know?

    Astragalus is derived from a Greek word to describe its reputation for increasing production of goat milk.

Additional information

  • Botanical description

    Astragalus is a perennial herb growing up to 150 cm high. The leaves are elliptic, pinnate, with many leaflets.

    The racemes are axillary, the calyx is 5 mm long and tubular. The root is flexible, long and covered with a tough, wrinkled, yellowish-brown epidermis. The woody interior is of a yellowish-white colour. Astragalus resembles and is closely related taxonomically to licorice.

  • Common names

    • Membranous milk-vetch root (Eng)
    • Huang qi (Chin)

    Alternate botanical names: The Pharmacopoeia of the People’s
    Republic of China includes both Astragalus membranaceus and A.
    membranaceus var. mongholicus (synonym: A. mongholicus) in its
    definition of astragalus. The Japanese Pharmacopoeia officially also
    permits substitutes including A. chrysopterus, A. floridus and A.
    tongolensis. The source of gum tragacanth is another species from
    mountainous areas of Iran and Iraq.

  • Safety

    Astragalus is safe for use during pregnancy and lactation (5).

    No adverse reactions are expected. There are some reviews suggesting that astragalus could disrupt the body’s response to acute infections. However these are theoretical assumptions based on laboratory studies which cannot mimic the digestive effects on the polysaccharide and saponin constituents.

  • Interactions

    None known

  • Contraindications

    None known

  • Preparation

    • Powdered dried root
    • Decoction
    • Tincture
    • Capsule
    • Liquid extract
  • Dosage

    Decoction: 10 to 30 g/day of the dried root as a decoction.

    Powdered dried: 10 to 30 g/day of the dried root as a powder.

    Liquid extract (1:2) : 4-8ml per day.

    Tincture (1:5 40%): Take 2-4ml three times a day.

    Larger doses are used in Traditional Chinese Medicine, for example, to treat paralysis (5).

  • Plant parts used

    Root

  • Constituents

    • Triterpenoid saponins (including astragalosides I to VIII)
    • Polysaccharides.
    • Isoflavonoids (including formononetin)
    • Phytosterols
    • Essential oil
  • Habitat

    Astragalus is native to the northern and eastern parts of China, as well as Mongolia and Korea. Growing in dry, sandy soil, often found in Mountain thickets, steppes, meadows, coniferous forests; montane belt at altitudes of 800 – 2000 metres.

  • Sustainability

    The IUCN Red List of Threatened Plants Status has no status for A. Membranaceous. The endangered rating of this plant is unclear, however this plant has been included in the China Rare Endangered Plant directory (7).

  • Quality control

    Traditionally, astragalus is taken as the powdered dried root or decoction. Water will extract the polysaccharides that are likely to be important to the plant’s benefits. Hot water extracts will also contain saponins. Alcoholic tinctures and extracts will contain only low levels of polysaccharides and only saponins if relatively high alcohol ratios are used.

    The Pharmacopoeia of the People’s Republic of China includes both Astragalus membranaceus and A. membranaceus var. mongholicus (synonym: A. mongholicus) in its definition of astragalus. The Japanese Pharmacopoeia officially also permits substitutes including A. chrysopterus, A. floridus and A. tongolensis.

    Herbal Medicines are often extremely safe to take, however it is important to supply herbal medicines from a reputed supplier. Sometimes herbs bought from unreputable sources are contaminated, adulterated or substituted with incorrect plant matter.

    Some important markers for quality to look for would be to look for certified organic labelling, ensuring that the correct scientific / botanical name is used and that suppliers can share the source of ingredients used in the product. 

    A supplier should also be able to tell you where the herbs have come from. There is more space for contamination and adulteration where supply chain is unknown. 

  • How to grow

    Growing Astragalus from seed is more difficult than other herbs. It is a perennial herb that prefers partial shade and well drained-dry soil (6).

    • The seeds require a minimum three week cold stratification period. To further aid germination, soak the seeds in water or scarify the seed coat with fine grade sandpaper before sowing. Seeds can take as long as nine weeks to sprout. 
    • Astraglaus prefers full sun to partial shade, in a well-drained sandy loam, neutral to alkaline pH and dry soil.
    • Astragalus herb plants can be directly seeded in the garden, but the general recommendation is to give them a head start by sowing indoors during late winter. Transplant seedlings as soon as the danger of frost has passed. 
    • Astragalus forms a taproot which can be harvested from a mature plant. it can take anywhere from two to four years for the taproot to grow to a usable size, roots of any age can be harvested. Older roots are considered more potent.
  • Recipe

    Winter Tonic Elixir

    This is a fun and easy-to-make ‘winter tonic elixir’ with a mix of herbs that raise your energy and warm you to the core.

    Ingredients:

    • Brandy 700ml/25fl oz
    • Amaretto 300ml/10fl oz
    • Ginseng root 20g/3/4oz
    • Astragalus 10g/1/3oz
    • Cinnamon bark 10g (about 2 quills)
    • Ashwagandha 5g
    • Ginger root powder 5g
    • Rosemary 2 sprigs
    • Orange peel 5g

    This makes 1 litre/35fl oz of tasty tincture.

    Method:

    • Blend the liquids and soak the herbs in it for 1 month and then strain. Bottle half for you and half for a friend.
    • Sip on cold winter nights to raise your spirits and keep you strong.

    Recipe from Cleanse, Nurture, Restore by Sebastian Pole

  • References

    1. Liu CH, Tsai CH, Li TC, et al. (2016) Effects of the traditional Chinese herb Astragalus membranaceus in patients with poststroke fatigue: A double-blind, randomized, controlled preliminary study. J Ethnopharmacol. 194: 954-962
    2. Fernandez ML, Thomas MS, Lemos BS, et al. (2018) TA-65, A Telomerase Activator improves Cardiovascular Markers in Patients with Metabolic Syndrome. Curr Pharm Des. 24(17): 1905-1911
    3. Li NY, Yu H, Li XL, et al. (2018) Astragalus Membranaceus Improving Asymptomatic Left Ventricular Diastolic Dysfunction in Postmenopausal Hypertensive Women with Metabolic Syndrome: A Prospective, Open-Labeled, Randomized Controlled Trial. Chin Med J (Engl). 131(5): 516-526
    4. Ai P, Yong G, Dingkun G, et al. (2008) Aqueous extract of Astragali Radix induces human natriuresis through enhancement of renal response to atrial natriuretic peptide. J Ethnopharmacol. 2008;116(3):413-421.
    5. Bone, K. and Mills, S. (2013). Principles and practice of phytotherapy modern herbal medicine. 2nd ed. Edinburgh Churchill Livingstone, Elsevier.
    6. www.gardeningknowhow.com. (n.d.). StackPath. [online] Available at: https://www.gardeningknowhow.com/edible/herbs/astragalus/astragalus-herb-plants.htm [Accessed 20 Sep. 2022].
    7. Yang, M., Li, Z., Liu, L., Bo, A., Zhang, C. and Li, M. (2020). Ecological niche modeling of Astragalus membranaceus var. mongholicus medicinal plants in Inner Mongolia, China. Scientific Reports, 10(1). doi:10.1038/s41598-020-69391-3.
Aromatic
An ‘aromatic’ remedy, high in volatile essential oils, was most often associated with calming and sometimes ‘warming’ the digestion. Most kitchen spices and herbs have this quality: they were used both as flavouring and to ease the digestion of sometimes challenging pre-industrial foods. Many aromatics are classed as ‘carminatives’ and are used to reduce colic, bloating and agitated digestion. They also often feature in respiratory remedies for colds, chest and other airway infections. They are also classic calming inhalants and massage oils, and are the basis of aromatherapy for their mental benefits.
Astringent taste
The puckering taste you get with many plants (the most familiar is black tea after being stewed too long, or some red wines) is produced by complex polyphenols such as tannins. Tannins are used in concentrated form (eg from oak bark) to make leather from animal skins. The process of ‘tanning’ involves the coagulation of relatively fluid proteins in living tissues into tight clotted fibres (similar to the process of boiling an egg). Tannins in effect turn exposed surfaces on the body into leather. In the case of the lining of mouth and upper digestive tract this is only temporary as new mucosa are replenished, but in the meantime can calm inflamed or irritated surfaces. In the case of open wounds tannins can be a life-saver – when strong (as in the bark of broadleaved trees) they can seal a damaged surface. One group of tannins, the reddish-brown ‘condensed tannins’ are procyanidins, which can reduce inflammation and oxidative damage.
Bitter
Bitters are a very complex group of phytochemicals that stimulate the bitter receptors in the mouth. They were some of the most valuable remedies in ancient medicine. They were experienced as stimulating appetite and switching on a wide range of key digestive functions, including increasing bile clearance from the liver (as bile is a key factor in bowel health this can be translated into improving bowel functions and the microbiome). Many of these reputations are being supported by new research on the role of bitter receptors in the mouth and elsewhere round the body. Bitters were also seen as ‘cooling’ reducing the intensity of some fevers and inflammatory diseases.
Blue-purple colouring
Any fruits with a blue-purple colouring contain high levels of the polyphenols known as anthocyanins. These work 1) on the walls of small blood vessels, helping to maintain capillary structure to reduce a key stage in inflammation, and improving the microcirculation to the tissues; 2) to improve retinal function and vision; 3) to support connective tissue repair around the body.
Cooling
Traditional ‘cold’ or cooling’ remedies often contain bitter phytonutrients such a iridoids (gentian), sesiquterpenes (chamomile), anthraquinones (rhubarb root), mucilages (marshmallow), some alkaloids and flavonoids. They tend to influence the digestive system, liver and kidneys. Cooling herbs do just that; they diffuse, drain and clear heat from areas of inflammation, redness and irritation. Sweet, bitter and astringent herbs tend to be cooling.
Hot
Traditional ‘hot’ or ‘heating’ remedies, often containing spice ingredients like capsaicin, the gingerols (ginger), piperine (black or long pepper), curcumin (turmeric) or the sulfurous isothiocyanates from mustard, horseradich or wasabi, generate warmth when taken. In modern times this might translate as thermogenic and circulatory stimulant effects. There is evidence of improved tissue blood flow with such remedies: this would lead to a reduction in build-up of metabolites and tissue damage. Heating remedies were used to counter the impact of cold, reducing any symptoms made worse in the cold. .
Mucilaginous
Mucilages are complex carbohydrate based plant constituents with a slimy or ‘unctuous’ feel especially when chewed or macerated in water. Their effect is due simply to their physical coating exposed surfaces. From prehistory they were most often used as wound remedies for their soothing and healing effects on damaged tissues. Nowadays they are used more for these effects on the digestive lining, from the throat to the stomach, where they can relieve irritation and inflammation such as pharyngitis and gastritis. Some of the prominent mucilaginous remedies like slippery elm, aloe vera and the seaweeds can be used as physical buffers to reduce the harm and pain caused by reflux of excess stomach acid. Mucilages are also widely used to reduce dry coughing. Here the effect seems to be by reflex through embryonic nerve connections: reduced signals from the upper digestive wall appear to translate as reduced activity of airway muscles and increased activity of airway mucus cells. Some seed mucilages, such as in psyllium seed, flaxseed (linseed) or guar bean survive digestion to provide bulking laxative effects in the bowel. These can also reduce rate of absorption of sugar and cholesterol. .
New-mown hay aroma
The familiar country odour of haymaking, of drying grass and other plants, is largely produced by coumarins (originally isolated from tonka beans – in French coumarou) and widely used in perfumery. They are chemically categorised as benzopyrone lactones and are important phytochemicals, with strong antioxidant activity in the laboratory and likely effects in modulating inflammation. They were most often associated with the calming effect linked to their use in stuffing mattresses and pillows and plants, high In coumarins were commonly used for these properties.
Resinous
Resins are most familiar as tacky discharges from pine trees (and as the substance in amber, and rosin for violin bows). They were most valued however as the basis of ancient commodities like frankincense and myrrh (two of the three gifts of the Three Wise Men to the baby Jesus) and getting access to their source was one benefit to Solomon for marrying the Queen of Sheba (now Ethiopia). Resins were the original antiseptic remedies, ground and applied as powders or pastes to wounds or inflamed tissues, and were also used for mummification. With alcohol distillation it was found that they could be dissolved in 90% alcohol and in this form they remain a most powerful mouthwash and gargle, for infected sore throats and gum disease. They never attracted much early research interest because they permanently coat expensive glassware! For use in the mouth, gums and throat hey are best combined with concentrated licorice extracts to keep the resins in suspension and add extra soothing properties. It appears that they work both as local antiseptics and by stimulating white blood cell activity under the mucosal surface. They feel extremely effective!
Salty
The salty flavour is immediately distinctive. A grain dropped onto the tongue is instantly moistening and a sprinkle on food enkindles digestion. This easily recognisable flavour has its receptors right at the front of the tongue. The salty flavor creates moisture and heat, a sinking and heavy effect which is very grounding for the nervous system and encourages stability. People who are solid and reliable become known as ‘the salt of the earth'.
Sharpness
The sharp taste of some fruits, and almost all unripe fruits, as well as vinegar and fermented foods, is produced by weak acids (the taste is generated by H+ ions from acids stimulating the sour taste buds). Sour taste buds are hard-wired to generate immediate reflex responses elsewhere in the body. Anyone who likes the refreshing taste of lemon or other citrus in the morning will know that one reflex effect is increased saliva production. Other effects are subjective rather than confirmed by research but there is a consistent view that they include increased digestive activity and contraction of the gallbladder.
Sweet
In the days when most people never tasted sugar, ‘sweetness’ was associated with the taste of basic foods: that of cooked vegetables, cereals and meat. In other words sweet was the quality of nourishment, and ‘tonic’ remedies. Describing a remedy as sweet generally led to that remedy being used in convalescence or recovery from illness. Interestingly, the plant constituents most often found in classic tonics like licorice, ginseng are plant steroids including saponins, which also have a sweet taste.

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