Astragalus root extract

What is astragalus?

Astragalus is a flowering plant in the pea family. Its root, known in traditional Chinese medicine as huang qi, has been used for centuries, usually combined with other herbs. Modern supplements contain dried root powder or root extracts, and the herb is often described as an adaptogen, a term for natural substances said to help the body resist physical and emotional stress (NCCIH).

Astragalus is promoted for a long list of uses, including colds and other upper respiratory infections, hay fever, asthma, chronic fatigue, chronic kidney disease, diabetes and immune support. Topical products are promoted for wound healing. In combination supplements sold online, it often appears in small amounts inside proprietary blends.

What the research says

NCCIH’s summary is blunt: there is not sufficient reliable scientific evidence to know whether astragalus is useful for any health condition (NCCIH). Much of the research comes from China, often tests astragalus alongside other herbs or drugs, and is of low quality.

Some reviews are worth knowing about, with their limits:

• Blood sugar. A 2024 review of 20 studies in 953 adults with type 2 diabetes found that adding astragalus to metformin lowered fasting glucose and HbA1c more than metformin alone, but most studies were low quality with risk of bias (NCCIH).
• Immune markers. A 2023 review of 19 studies with 1,094 participants reported stronger immune responses and lower inflammatory cytokines, but the studies were small and varied widely in design (NCCIH).
• Kidney disease. A 2023 review of 50 studies with 3,423 participants found that adding astragalus to standard care for membranous nephropathy improved some kidney markers, again with low-quality, small studies.
• Fatigue and heart conditions. Systematic reviews have looked at astragalus for cancer-related fatigue (Sheng et al., 2025) and heart failure (Han et al., 2024), mostly as an add-on to conventional treatment.

We found no human trials showing that astragalus improves hearing or tinnitus. Laboratory work on astragalus compounds and inner ear cells exists, but cell and animal findings do not tell us what a supplement does in people.

How it’s used in supplements

Astragalus root is sold as capsules, tablets, liquid extracts and teas. NCCIH notes that oral doses of up to 60 grams a day for as long as four months do not seem to cause adverse effects in studies, though a thorough safety evaluation has not been done (NCCIH). In multi-ingredient blends, the amount is often undisclosed and probably far smaller than in research.

Safety points to keep in mind: astragalus might worsen autoimmune diseases, so people with conditions such as lupus, rheumatoid arthritis or multiple sclerosis should avoid it, and it may interact with drugs that suppress the immune system, such as those used after organ transplants. Little is known about its safety in pregnancy or breastfeeding, and some animal research suggests it can be toxic to the fetus (NCCIH). Because it may affect blood sugar, people taking diabetes medicines should talk to their doctor before using it. As with any herb, tell your health care provider if you take astragalus.