What are the Most Common Astragalus Side Effects?

Astragalus, a Chinese medicinal root used as an immune supplement and constipation treatment, can have some side effects in higher doses, when used regularly, or when used in conjunction with other medications. The most common astragalus side effects involve issues with immune suppression drugs or autoimmune diseases. Astragalus can reduce the effect of immune suppression drugs beyond healthy or safe parameters. In the case of autoimmune diseases, the root can boost immune system function and trigger, or worsen, disease symptoms.

Patients on corticosteroids or transplant patients using cyclophosphamide may suffer astragalus side effects. The root can decrease the effectiveness of these drugs. Such medications are usually used to lower immune response. As an immune booster, astralagus counteracts by increasing immune response. Side effects related to autoimmune diseases are also associated with the drugs used to treat said diseases. Drugs for HIV/AIDS, lupus, and multiple sclerosis can all interact with astragalus to reduce the effectiveness of the treatments, although astragalus has been suggested as an alternative treatment to boost immune response in the case of immune deficiency diseases.

Lithium can also have a negative effect if combined with the root. Astragalus can interfere with the body's ability to process and dispose of that drug, which can lead to toxic levels of lithium accumulation. As a diuretic, the root can also have cross-reactions, or interactions, with prescription diuretics. Other drugs that may react are antiviral medications, anticoagulants, and medications for hypoglycemia.

As a laxative, astragalus can lead to dehydration if overdosed or used for too long. Other laxative-related astragalus side effects include laxative dependence, poor bowel function, colon damage, and chronic constipation. Most effects can be treated by reducing or eliminating use of supplements containing astragalus.

The astragalus side effects for pregnant or nursing women are unknown. Doctors and other medical professionals advise avoiding foods, beverages, or supplements containing astragalus if expecting or breastfeeding. Astragalus also should not be given to children, even in limited doses. Dosages vary by height, weight, and age, and can be difficult to gauge this for children.

Some may also suffer an allergic reaction to astragalus. The plant is a member of the milk vetch family, and can trigger reactions in those with allergies to peas or related plants. Others have reported astragalus side effects from a cross-reaction with soapbark. Certain species of astragalus have been involved in cases of livestock poisoning. These species are not the same as those used for human treatments.