Side Effects of Astragalus

Patients with nephrotic syndrome (health problems related to kidney damage) are susceptible to infections. A 2013 research review found that taking astragalus may be associated with a lower risk of upper respiratory tract infections in children with nephrotic syndrome than prednisone treatment alone. However, the review concluded the studies were of low quality.

An astragalus-based herbal formula didn’t extend the lives of people with advanced lung cancer, a small 2009 trial reported. The study (with 24 people) was supported in part by the National Center for Complementary and Integrative Health (NCCIH).

Dosage Of Astragalus

Astragalus may be safe when used orally and appropriately. (Doses up to 60 grams daily for up to 4 months have been used without reported adverse effects.) Some possible side effects with oral use include rash, itching, nasal symptoms, or stomach discomfort, but these are uncommon.

Astragalus may interact with medications that suppress the immune system.
Some astragalus species, usually not found in dietary supplements, can be toxic to livestock. 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. Too much selenium can lead to diarrhea, irritability, nausea, skin rashes, and nervous system problems.

Little is known about whether it’s safe to use astragalus during pregnancy or while breastfeeding. Some research in animals suggests that astragalus can be toxic to the mother and fetus.


Take charge of your health—talk with your health care providers about any complementary health approaches you use. Together, you can make shared, well-informed decisions.


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.