Astragalus

Astragalus membranaceus

Family: Fabaceae Part used: Root

Key Compounds

• Astragaloside I
• Astragaloside II
• Astragaloside III
• Astragaloside IV
• Cycloastragenol
• Astragalus polysaccharides (APS)
• Calycosin
• Formononetin
• Ononin
• Astragalin
• Kumatakenin
• Betaine

Traditional Use

• Classical TCM qi tonic — 黄耆 (huangqi in Chinese, ōgi in Japanese) used for over 2,000 years as the primary herb for wei qi (defensive energy), surface protection, and immune resilience; appears in the *Shennong Bencao Jing* as superior-class medicine
• Classical kampo medicine — 黄耆 (ōgi) is a Japanese Pharmacopoeia-approved crude drug appearing in kampo formulas for qi deficiency, fatigue, digestive weakness, and surface conditions; covered under Japan's national health insurance when prescribed as part of a kampo formula
• Immunomodulatory research — astragalus polysaccharides (APS) stimulate macrophage and natural killer cell activity in laboratory and clinical studies; multiple Chinese clinical trials on adjuvant use alongside cancer chemotherapy showing reduced side effects and maintained immune function
• Telomerase activation research — astragaloside IV and its aglycone cycloastragenol shown to activate telomerase in laboratory studies; basis for commercial supplements claiming anti-aging properties; evidence remains primarily in vitro and animal studies with limited human data
• Culinary medicinal — added to soups and broths during cooking in Chinese and Korean food traditions; the root is simmered for 45–60 minutes and removed; long-standing food-medicine hybrid practice

Astragalus root, when dried and sliced for commercial sale, looks like a tongue depressor.

Flat, pale golden-yellow, fibrous, slightly sweet-smelling. It does not look like a medicine. It looks like something a pharmacist would use to hold your tongue down while checking your throat. This is, in fact, a practical identification feature: when you order dried astragalus root and it arrives as neat flat slices in a bag, that is what you ordered.

The plant has been used as a qi tonic in Chinese medicine for over 2,000 years. It is the primary herb for what the classical texts describe as wei qi — the defensive energy that protects the body’s surface and maintains immune resilience. When people got tired easily, caught colds repeatedly, or felt depleted after illness or hard work, astragalus was part of the prescription. It still is.

Meet the plant

A perennial herb, 30–100 cm, with pinnate compound leaves and small purple to white flowers. It is a legume — in the Fabaceae family alongside licorice, codonopsis, peas, and clover. The root is harvested after 4–7 years of growth. The older the root, the higher the astragaloside content, and the more expensive the commercial material.

The genus Astragalus is one of the largest plant genera on earth — over 3,000 species. Most are medicinally unremarkable. The medicinal astragalus is A. membranaceus or the closely related A. mongholicus, which are treated as equivalent in most herbal literature.

The defensive medicine

The classical Chinese medical framework describes two kinds of qi relevant to immune function: ying qi, which circulates inside the body, and wei qi, the defensive energy that circulates near the surface and protects against external pathogenic influences. Astragalus tonifies wei qi specifically. This is why it is prescribed for people who catch colds frequently, who heal slowly, who sweat spontaneously (a sign of wei qi weakness in classical theory), and who feel generally permeable to illness.

The classical text Shennong Bencao Jing (1st century CE) classifies astragalus in the superior category — herbs appropriate for long-term daily use. The same text notes it “tonifies the deficiency and weakness of the five internal organs.”

The classical observations are aligned, in a broad way, with what modern research has found: astragalus polysaccharides stimulate immune cell activity. The mechanism was not known in the Han dynasty. The observation that the root made depleted people more robust over time was.

The telomere story

In 2007, a supplement called TA-65 was launched. Its active compound was cycloastragenol — the aglycone of astragaloside IV, one of the cycloartane triterpenoid saponins in astragalus root.

Laboratory studies had shown that astragaloside IV activated telomerase. Telomerase extends telomeres — the protective caps on chromosome ends that shorten with each cell division. Telomere shortening is associated with cellular aging. Longer telomeres, theoretically, means slower cellular aging.

TA-65 was priced at hundreds to thousands of dollars per month and marketed with claims about reversing cellular aging. It attracted significant media coverage and significant scientific scepticism.

The problem was the evidence base. The studies showing telomerase activation were primarily in cell cultures and mice. The available human studies were small, short, and funded by the supplement manufacturer. No large independent trial has demonstrated that supplemental astragaloside IV extends human telomeres to clinically meaningful degree.

The biology is genuinely interesting. The commercial claims were not supported by the clinical evidence available. The supplement market moved on. Astragalus root itself — as a traditional tonic at accessible doses — continued to be used precisely as it had been for 2,000 years, without the telomere story attached.

The chemistry

Astragalosides are the defining compounds — cycloartane-type triterpenoid saponins. Astragaloside IV is the most studied (telomerase activation). Astragalosides I–III have various biological activities. Cycloastragenol is the aglycone (sugar-stripped form) of astragaloside IV and is more bioavailable.

Astragalus polysaccharides (APS) are the immunomodulatory fraction. Multiple structural types have been identified; they stimulate macrophages, increase NK cell activity, and promote interferon production. These are the compounds behind the immune-support applications.

Isoflavones — calycosin and formononetin — contribute anti-inflammatory and antioxidant activity. Calycosin in particular has been studied for cardiovascular protection.

What people actually do with it

In broth and soup: The traditional and arguably most pleasant form. Add 10–20 g of dried sliced root to chicken soup, pork bone broth, or congee. Simmer 45–60 minutes. Remove the root (or leave it — it is edible but fibrous). The broth will be slightly sweeter and the medicinal compounds will infuse the liquid. This is a traditional food-medicine practice in Chinese and Korean cooking. Add alongside codonopsis root, goji berries, and jujube dates for the classical qi-tonifying broth.

Decoction: 10–30 g simmered in 500 mL water for 30–45 minutes. Mildly sweet, slightly earthy, more palatable than most medicinal decoctions. Traditional dose in classical formulas is higher than Western supplement doses.

Extract capsules: Standardised to astragaloside IV content. 500–1,500 mg daily of standardised extract. Ensure the product specifies the species (A. membranaceus or A. mongholicus) — generic “astragalus” may be a different species.

In kampo formulas: Prescribed by Japanese doctors and kampo practitioners as part of classical formulas. Covered by Japanese national health insurance. Ōgi-kenchu-to (黄耆建中湯) and related formulas are prescribed for fatigue and digestive weakness.

Could you grow this yourself?

Yes. Astragalus is more tolerant of Japanese conditions than most people assume.

The plant prefers well-drained soil, full sun to partial shade, and moderate moisture. It grows in northeast China and Siberia — conditions compatible with most of Honshu and Hokkaido. Seeds germinate readily (scarify or soak in warm water overnight before planting). The root is harvested after 4+ years.

The vine grows to about 1 metre with minimal support. It is a legume, which means it fixes nitrogen and improves soil while growing. The flowers are small and not showy. In autumn of year 4–5, dig the root carefully — it is long and fragile. Clean, dry, and slice for storage.

Commercial Chinese astragalus is grown primarily in Gansu, Inner Mongolia, and Shanxi at scale. Home-grown root will have variable astragaloside content and cannot be standardised. But the cooking tradition does not require standardised extract — it requires the root.

Astragalus (黄耆/ōgi) in Japan

Japan’s relationship with astragalus is primarily through the kampo medical system rather than the supplement market.

黄耆 (ōgi) is a Japanese Pharmacopoeia-approved crude drug with a long history in classical Japanese herbal medicine. It appears in Ōgi-kenchu-to, Bōi-ōgi-to, Bōfūtsū-shōsan, and other classical formulas prescribed through Japan’s national health insurance system. Japanese doctors trained in both Western and kampo medicine prescribe these formulas for fatigue, digestive weakness, spontaneous sweating, and recurrent infections. The coverage under NHI means astragalus is available to patients without supplement prices.

The supplement market for astragalus exists in Japan — standardised extract capsules are available — but it is smaller than for some other TCM herbs because the kampo route provides an alternative. The telomere marketing wave (TA-65 and related products) was less prominent in Japan than in North American markets.

The culinary tradition — adding the root to soup — is present in Japanese households influenced by Chinese and Korean cooking, but is not deeply embedded in traditional Japanese food culture in the way it is in Chinese and Korean homes.

Things you’re probably wondering

What is the difference between astragalus and codonopsis? Both are qi tonics; both appear in classical formulas. Astragalus (ōgi) focuses more on wei qi and immune/surface defence. Codonopsis (tōjin) focuses more on the spleen-stomach digestive axis. They are frequently combined.

What is the telomere story? Astragaloside IV activates telomerase in laboratory studies. A supplement (TA-65) was marketed on this basis. Human clinical evidence is limited. The biology is interesting; the commercial claims ran significantly ahead of the evidence.

Can you cook with it? Yes — traditional practice. Add dried sliced root to soups and broths during cooking, simmer 45–60 minutes, remove before eating. Standard approach in Chinese and Korean herbal cooking traditions.

Where can you find it in Japan? As ōgi in kampo formulas through hospitals and clinics (NHI covered). As dried root at TCM pharmacies. As supplement capsules at natural food stores and supplement retailers.

Botanical details

The full compound list

See Also

• Codonopsis — paired qi tonic; the two are often combined in classical kampo and TCM formulas
• Reishi — another superior-class medicine with immune-modulating polysaccharides
• Eleuthero — adaptogen with overlapping immune and fatigue-recovery applications

References

• Bensky, D. et al. (2004). Chinese Herbal Medicine: Materia Medica (3rd ed.). Eastland Press.
• Zhao, L.H. et al. (2015). Astragalus membranaceus: Overview of its immunomodulatory effects. Journal of Ethnopharmacology, 172, 337–342.
• Harley, C.B. et al. (2011). A natural product telomerase activator as part of a health maintenance program. Rejuvenation Research, 14(1), 45–56.
• Liu, P. et al. (2017). Astragalus polysaccharides and astragaloside IV: Mechanisms and pharmacological activities. Phytomedicine, 29, 89–100.