Because of the lack of scientific studies, it is unknown whether celery seed interacts with other herbs and medications. However, people who take the following medications should avoid celery seed:

Diuretics (water pills) --Celery seed also has diuretic properties and could make the effects of these medications stronger, resulting in dehydration. If you take prescription diuretics, talk to your doctor before taking celery seed.

Anticoagulants (blood-thinning medications) --Celery contains chemicals that may thin the blood and make the effects of these medications stronger, which could increase the risk of excessive bleeding. Do not take celery seed if you also take prescription anticoagulants such as warfarin (Coumadin).