Astragalus
Summary
Astragalus root is a staple of traditional Chinese medicine. In a 48-week Hong Kong trial in diabetic kidney disease, add-on granules slowed kidney-function decline but did not change albuminuria. A 61-person trial found less post-stroke fatigue. The NIH advises people with autoimmune disease to avoid it and notes possible interactions with immune-suppressing drugs.
Key facts
- NIH: people with autoimmune diseases should avoid astragalus, and it may interact with immune-suppressing medicines; animal research suggests fetal toxicity in pregnancy[6]
- Add-on granules (15 g raw herb equivalent daily) slowed eGFR decline by 4.6 mL/min/1.73 m2 per year over 48 weeks; albuminuria did not differ from standard care[1]
- 2.8 g three times daily for 28 days lowered fatigue scores more than placebo in 61 completers[2]
- NIH: there is not sufficient reliable evidence to know whether astragalus is useful for any health condition[6]
- 4 graded human outcomes on this page
- October 13, 2026
How it works
ProposedAstragalus root contains polysaccharides, saponins such as astragaloside IV and flavonoids. It is promoted as an immune-modulating adaptogen; a 2023 review cited by the NIH found enhanced immune responses and lower pro-inflammatory cytokines in small studies. Mechanisms behind kidney or fatigue findings are not established.[6]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Kidney function | Grade C | Improved | Meta-analysis · n = 236 · 2019 | 2 rows |
| Fatigue | Grade D | Improved | RCT · n = 61 · 2016 | 1 row |
| Allergy | Grade D | Mixed | RCT · n = 48 · 2010 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Albuminuria in diabetic kidney disease (oral preparations) | Improved | Grade C | Meta-analysis · n = 236 · 2019 People with diabetic kidney disease in 4 RCTs of oral astragalus added to conventional therapy (China) Form: Oral Astragalus membranaceus preparations · Dose: Varied by trial · Duration: Short term Albuminuria fell more than with conventional therapy alone (SMD -1.27, 95% CI -1.82 to -0.73). | 31034954 (opens PubMed)Source [4] |
| Kidney function decline in diabetic kidney disease | Improved | Grade C | RCT · n = 118 · 2024 Adults with type 2 diabetes, stage 2-3 chronic kidney disease and macroalbuminuria (Hong Kong) Form: Oral astragalus granules added to standard care · Dose: 15 g raw herb equivalent per day · Duration: 48 weeks eGFR declined 4.6 mL/min/1.73 m2 per year more slowly than with standard care alone (95% CI 1.5-7.6); albuminuria slope did not differ; endpoint systolic blood pressure was 7.9 mm Hg lower. | 38810556 (opens PubMed)Source [1] |
| Post-stroke fatigue | Improved | Grade D | RCT · n = 61 · 2016 Adults with fatigue after stroke (Taiwan; 64 randomised) Form: Astragalus membranaceus extract · Dose: 2.8 g three times daily · Duration: 28 days Brief Fatigue Inventory scores fell 17.8 points vs 8.0 with placebo; cognitive, social functioning and global quality-of-life scores also improved. | 27773802 (opens PubMed)Source [2] |
| Seasonal allergic rhinitis symptoms | Mixed | Grade D | RCT · n = 48 · 2010 Adults with moderate-to-severe seasonal allergic rhinitis (Croatia) Form: Herbal and mineral complex containing astragalus (Lectranal) · Dose: Product dose as labelled (amount not stated in the abstract) · Duration: 6 weeks Runny nose improved more than placebo, but the other primary outcomes did not differ between groups. | 19504468 (opens PubMed)Source [3] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Root granules or decoction | Varies[5] | In 14 volunteers, 4 g twice daily of root extract granules for 7 days did not change fexofenadine (P-glycoprotein probe) blood levels.[5] | Adverse events were recorded in both arms of the 48-week kidney trial; NIH notes up to 60 g/day for 4 months does not seem to cause adverse effects.[1][6] | Kidney trial (15 g raw herb equivalent/day), fatigue trial (8.4 g/day) |
| Capsules, drops and isolated astragalosides | Varies[6] | No human pharmacokinetic data in the cited sources.[6] | A thorough safety evaluation has not been done.[6] | Not tested in the trials cited here |
Studied doses
Doses studied in human trials ranged from 8.4 g/day of root extract for 28 days (post-stroke fatigue) to granules equivalent to 15 g/day of raw herb for 48 weeks (diabetic kidney disease).[1][2]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Medicines
- Immune-suppressing medicinesNIH fact sheetNIH says astragalus may interact with medications that suppress the immune system; MSK says it can make them less effective and reports a patient whose tacrolimus levels fell by nearly half while taking astragalus-containing granules.[6][7]
- Warfarin and other blood thinnersReviewMSK advises talking to a provider first because astragalus may increase bleeding risk.[7]
- Blood-pressure medicines and diureticsReviewMSK notes astragalus can lower blood pressure and had natriuretic effects in a small study, so effects may add up; clinical relevance is not known.[7]
- P-glycoprotein substrate drugsPK studySeven days of root granules did not change fexofenadine levels, suggesting no meaningful P-glycoprotein effect.[5]
Who should be careful
- Autoimmune disease
- NIH advises people with autoimmune diseases to avoid astragalus because it might worsen symptoms.[6]
- Transplant recipients and others on immune-suppressing drugs
- Astragalus may interact with these medicines.[6][7]
- Pregnancy and breastfeeding
- Little is known about safety, and animal research suggests it can be toxic to the fetus.[6]
- People on blood thinners
- MSK flags a possible increase in bleeding risk with warfarin.[7]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Safety first
Usually tolerated, but immune effects matter for some people.
How to read the label
Frequently asked questions
Does astragalus boost the immune system?
Small studies report immune-marker changes, but NIH says reliable evidence for any health condition is lacking.[6]
Is astragalus safe with autoimmune disease?
NIH advises people with autoimmune diseases to avoid it.[6]
Can I take it with immune-suppressing drugs?
NIH says it may interact with them; transplant recipients should not combine them without their care team.[6]
Does astragalus help kidney disease in diabetes?
One 48-week trial found slower eGFR decline as an add-on, but no change in albuminuria and no placebo control.[1]
Is astragalus safe in pregnancy?
Little is known, and animal research suggests fetal toxicity.[6]
Sources
- [1]Add-on astragalus in type 2 diabetes and chronic kidney disease: A multi-center, assessor-blind, randomized controlled trial.. Phytomedicine, 2024. RCT
- [2]Effects of the traditional Chinese herb Astragalus membranaceus in patients with poststroke fatigue: A double-blind, randomized, controlled preliminary study.. J Ethnopharmacol, 2016. RCT
- [3]Efficacy and safety of Astragalus membranaceus in the treatment of patients with seasonal allergic rhinitis.. Phytother Res, 2010. RCT
- [4]Astragalus membranaceus (Huang Qi) as adjunctive therapy for diabetic kidney disease: An updated systematic review and meta-analysis.. J Ethnopharmacol, 2019. meta-analysis
- [5]Investigation on modulation of human P-gp by multiple doses of Radix Astragali extract granules using fexofenadine as a phenotyping probe.. J Ethnopharmacol, 2013. PK-study
- [6]Astragalus: Usefulness and Safety. National Center for Complementary and Integrative Health (NIH), 2025. fact-sheet
- [7]Astragalus (About Herbs). Memorial Sloan Kettering Cancer Center, 2023. database
What changed
- Initial editorial evidence review: source titles and years taken from NCBI E-utilities esummary (no retraction or expression-of-concern flags), every evidence row, dose, n and duration read against the PubMed abstract or full text, funding and author affiliations checked where available, and grades held conservative.