If you are currently being treated with any of the following medications, you should not use astragalus without first talking to your healthcare provider.

Antiviral medications
Astragalus may increase the effects of some antiviral medications such as acyclovir and interferon.

Cyclophosphamide
Astragalus may also counteract the immune-suppressing effects of cyclophosphamide, a medication used to reduce the chances of rejection in transplant recipients.