Astragalus

Background

Astragalus has been used for centuries in traditional Chinese medicine in combination with other herbs, such as ginseng, dong quai, and licorice.

There are more than 2,000 species of astragalus.

Astragalus has been used as a dietary supplement for many conditions, including for diarrhea, fatigue, anorexia, upper respiratory infections, heart disease, hepatitis, fibromyalgia, and as an adjunctive therapy for cancer.

The root of the astragalus plant is put in soups, teas, extracts, or capsules.

How Much Do We Know?

There are no high-quality studies in people of astragalus for any health conditions.

What Have We Learned?

Patients with nephrotic syndrome (health problems related to kidney damage) are susceptible to infections. A 2012 research review found that taking astragalus granules may be associated with a lower risk of infections in children with nephrotic syndrome. However, the review concluded that the studies were poor quality.

People with diabetic nephropathy (a type of kidney disease) who received an intravenous drip of astragalus over a period of 2 to 6 weeks did better on some measures of kidney function, compared to people who didn’t get astragalus, according to a 2011 analysis of 25 studies. However, most of the trials involved were poor quality.

There’s weak evidence that astragalus may help heart function in some patients with viral myocarditis (an infection of the heart), a 2013 research review showed.

Because of limitations in the studies, a 2013 research review on the effects of astragalus on fatty liver disease, which causes fat to build up in liver cells, couldn’t determine whether astragalus helps.

An astragalus-based herbal formula didn’t extend the life of patients with advanced lung cancer, a small 2009 trial reported. The study was supported in part by the National Center for Complementary and Integrative Health (NCCIH).

What Do We Know About Safety?

Astragalus is considered safe for many adults. The most commonly reported side effects are diarrhea and other mild gastrointestinal effects. However, it may affect blood sugar levels and blood pressure and be risky for people with certain health problems, such as blood disorders, diabetes, or hypertension.

Astragalus may interact with medications that suppress the immune system, such as drugs taken by organ transplant recipients and some cancer patients.

Some astragalus species, usually not found in dietary supplements, can be toxic. Several species that grow in the United States contain the neurotoxin swainsonine and have caused “locoweed” poisoning in animals. Other species contain potentially toxic levels of selenium.

Key References

-NIH