Astragalus (Hwanggi, 황기)
Qi tonic of the Silk Road, so far more soup than medicine
Evidence grade 2 of 5, Thin. Read how the Atlas grades evidence.
Both bodies of trial data are weaker than their headlines. Sheng and colleagues (Integrative Cancer Therapies, 2025) pooled 8 RCTs and 804 patients for cancer-related fatigue and found a large effect (SMD -1.63), while grading the evidence low for fatigue and very low for quality of life, citing inadequate blinding and concealment. Zhang and colleagues (J Ethnopharmacol, 2019) pooled 32 RCTs for albuminuria in diabetic kidney disease and reported reductions, again at low quality, with heterogeneity and publication bias, and mostly using an injectable extract rather than the oral root. Nearly all are small, single-center, Chinese. NCCIH holds that there is not sufficient reliable evidence to know whether astragalus helps any condition.
Reference only. Not medical advice.
What can go wrong
Oral astragalus appears reasonably safe in food and tea amounts. NCCIH notes doses up to 60 g daily have been used for up to four months, though no thorough safety evaluation stands behind that figure. Because the polysaccharides stimulate immune activity in laboratory models, NCCIH advises people with autoimmune disease to avoid it and warns of interaction with immunosuppressant drugs, which matters for transplant patients. Animal data raise questions about fetal toxicity, so pregnancy is not a setting for it. Supply quality is a problem. Radix Astragali is substituted with Radix Hedysarum, and value-chain reviews describe purity standards failing to keep pace with demand, producing material with insufficient marker compounds, pesticide residues and heavy metals. The genus also includes the toxic North American locoweeds, which share a name and nothing else.
Astragalus is the dried root of Astragalus membranaceus, a legume of the dry uplands of northern China, Korea, Mongolia and Siberia. Korean medicine knows it as hwanggi, Chinese medicine as huang qi, Japanese Kampo as ogi. In all three systems it is the archetypal qi tonic, given for fatigue, poor appetite, weak digestion, spontaneous sweating and slow-healing wounds, and it functions as a food as much as a drug. Korean households simmer the sliced root in samgyetang, the ginseng chicken soup eaten during the hottest weeks of summer. Modern research has concentrated on two uses, cancer-related fatigue and diabetic kidney disease, and both have produced meta-analyses that favor astragalus while the reviewing authors rate the underlying trials as low quality. NCCIH's position is that there is not sufficient reliable evidence to know whether astragalus is useful for any health condition. The root is broadly well tolerated, though it is not inert for people taking immunosuppressant drugs.
Root tonic used across East Asia for fatigue and immunity; meta-analyses for cancer fatigue and kidney disease favor it, but the reviewers themselves rate the trials low quality.
How it is supposed to work
The root carries cycloartane saponins (astragalosides), isoflavones such as calycosin and formononetin, and large polysaccharides. Astragaloside IV is the pharmacopoeial marker and the best studied, with animal and cell work reporting antioxidant and podocyte-protective effects that would fit the kidney findings. Polysaccharides show immunomodulating activity in lab models, the source of the immune-booster framing. Whether any of this reaches useful concentrations by mouth is unestablished, and astragaloside IV's oral bioavailability is poor.
What people get wrong
Often saidAstragalus boosts the immune system.
ActuallyImmunomodulating activity is documented in cell and animal models, but no human trial has shown that it prevents or shortens infections. NCCIH advises people with autoimmune disease to avoid astragalus for precisely the same theoretical reason, which shows how little the phrase settles.
Often saidThe kidney trials prove that oral astragalus protects kidneys.
ActuallyThe 2019 meta-analysis rested largely on an injectable astragalus preparation given alongside standard care in Chinese hospitals, was rated low quality with significant publication bias, and its authors specifically called for trials of the oral form. It does not transfer to retail capsules.
Often saidTwo thousand years of safe use makes modern testing unnecessary.
ActuallyLong food use supports general tolerability, and it detects nothing about the interaction with immunosuppressant drugs, which did not exist for most of that history, or about the adulteration of commercial Radix Astragali with Hedysarum root, which is a supply-chain problem of the last few decades.
Who profits, and who pushes back
National Center for Complementary and Integrative Health (NCCIH)
States there is not sufficient reliable scientific evidence to know whether astragalus is useful for any health condition, advises people with autoimmune diseases to avoid it because it might worsen symptoms, and flags possible interaction with immunosuppressive medications.
Xia Sheng and colleagues
Report that astragalus reduced cancer-related fatigue across 8 RCTs and 804 patients, while grading the evidence low for fatigue and very low for quality of life, and concluding that the evidence is not yet adequate to provide strong support for clinical use.
Lei Zhang, Johannah Shergis and colleagues
Report short-term reductions in albuminuria and proteinuria with adjunctive astragalus preparations, while cautioning that the evidence is low quality with significant heterogeneity and publication bias, and calling for trials of the oral form on patient-important outcomes.
Authors of the 2020 Radix Astragali value-chain review, Frontiers in Pharmacology
Describe purity and identification standards failing to keep pace with expanding demand, yielding supply chains affected by adulteration, insufficient active ingredient, excessive pesticide residues and heavy metals.
Where the research comes from
Most of the published research on this comes from one place. 100% of it is from Native to the dry uplands of northern China, Korea, Mongolia and Siberia; carried along Silk Road corridors into Central Asia, and into Western supplement retail in the twentieth century. Findings that no unrelated group has reproduced are weaker than the study count makes them look.
| Place | Share of published research |
|---|---|
| Native to the dry uplands of northern China, Korea, Mongolia and Siberia; carried along Silk Road corridors into Central Asia, and into Western supplement retail in the twentieth century | 100% |
How we got here
Both Astragalus membranaceus and its variety mongholicus are accepted as official Radix Astragali, so one trade name covers two botanical sources from different growing regions, and some taxonomic treatments raise the variety to Astragalus mongholicus, which splits the research literature across binomials. The Latin drug name is also where a durable confusion starts: Radix Hedysarum (Hedysarum polybotrys), sold in Chinese practice as hongqi or red astragalus, is a different genus with different chemistry and is a common substitute in commercial supply. English adds a further hazard, since the genus Astragalus includes the North American locoweeds, toxic range plants that share the genus name and nothing of the use.
The root enters the written record in the Shennong Bencao Jing, the Han-era Classic of Materia Medica compiled around the second or third century CE, where it sits among the superior class of medicines meant for long use rather than acute illness. That text credits it with reinforcing healthy qi, dispelling pathogenic factors, promoting urination and reducing swelling. Its heartland is the dry north, Shanxi and Inner Mongolia in particular, and its trade followed the Silk Road corridors, which is why the same root appears as ethnomedicine in Mongolia, Kazakhstan, the Russian Federation and Korea rather than in China alone. Korean practice absorbed it early and gave it the name hwanggi, embedding it in both the formal hanbang pharmacopoeia and household cooking. Li Shizhen's Bencao Gangmu of 1596 consolidated its indications. Western herbalism met it only in the twentieth century.
- c. 200-300 CERecorded in the Shennong Bencao Jing as a superior-class medicine for reinforcing healthy qi
- Han to Tang dynastiesTrade along Silk Road corridors carries the root into Mongolia, Central Asia and Korea, where it becomes hwanggi
- 1596Li Shizhen's Bencao Gangmu consolidates huang qi among the tonic roots
- 2010First meta-analysis of astragalus in diabetic nephropathy published in Journal of Ethnopharmacology
- 2019Zhang and colleagues update the diabetic kidney disease meta-analysis across 32 RCTs and rate the evidence low quality with publication bias
- 2020Frontiers in Pharmacology value-chain review documents adulteration and quality decline in commercial Radix Astragali
- 2025Sheng and colleagues find benefit for cancer-related fatigue across 8 RCTs while grading the evidence low and very low
How it is understood
In Korean hanbang, hwanggi belongs to the qi-replenishing class and is paired with ginseng in tonics for people described as depleted, sweaty and easily tired. Its most visible place is culinary. Samgyetang, a young chicken stuffed with rice and simmered with ginseng and hwanggi, is eaten on the three sambok days of midsummer, on the reasoning that summer heat is answered with warmth rather than cooling. Chinese and Japanese practice put the same root into Fu Zheng therapy, supporting the body's own resistance rather than attacking a disease.
At a glance
- Botanical source
- Astragalus membranaceus root, pharmacopoeial name Radix Astragali
- Marker compound
- Astragaloside IV, plus calycosin-7-O-β-D-glucoside
- First recorded
- Shennong Bencao Jing, c. 200-300 CE, superior class
- NCCIH verdict
- Insufficient reliable evidence for any health condition
What this entry does not yet cover
What follows is unfinished work on our side, not a finding about Astragalus (Hwanggi, 황기). A short entry is not a safe entry.
- Cost and market. We have not documented what it sells for or who sells it.
- Supply chain. We have not mapped where it is made.
- Who uses it. We have not documented the user groups.
- What could change. No forward-looking summary yet.
- How it compares. We have not set it against the alternatives.
- Children and teenagers. We have not checked what is known about younger people.
- What people take it for. We have not catalogued the claims made for it.
Sources
NCCIH holds there is insufficient reliable evidence for any condition; autoimmune and immunosuppressant cautions; 60 g/day for 4 months figure; fetal toxicity signal in animals
8 RCTs, 804 patients, SMD -1.63 for cancer-related fatigue, GRADE low for CRF and very low for QoL
32 RCTs for albuminuria in diabetic kidney disease; low quality evidence, heterogeneity and publication bias; largely injectable form
Zhang L, Shergis JL, Yang L et al., Journal of Ethnopharmacology 239:111921, 2019
Earlier meta-analysis of astragalus in diabetic nephropathy establishing the research line
First recorded in Shennong Bencao Jing c. 200-300 CE as superior-class; qi-reinforcing indications; names hwanggi/ogi; ethnomedicine in Korea, Mongolia, Kazakhstan, Russia; chemistry and toxicology
Adulteration, declining quality, pesticide residues and heavy metals in the Radix Astragali value chain; astragaloside and calycosin-7-O-glucoside as markers
Quality Control of Radix Astragali Along Its Value Chains, Frontiers in Pharmacology, 2020
Radix Astragali is substituted with Radix Hedysarum (Hedysarum polybotrys), which has different bioactivity; authentication is difficult
Silk Road diffusion of astragalus; regional ethnomedical use across Central and East Asia
Oral astragalus root in mild to moderate chronic kidney disease, self-controlled case series showing the limits of uncontrolled designs