The word chamomile actually refers to a range of different daisy-like plants, which are a member of the Asteraceae family. There are many different species of chamomile, the two most commonly being German chamomile (Marticaria recutita) and Roman chamomile (Chamaemelum 

Chamomile fed daily has been known to have a calming effect on the highly anxious.

chamomile is not swabbable in horses. It has 3 active constituents none of which can be found on the 2019 FEI prohibited substances list.

Chamomile is it swabbable or not ? 

NO 

The active constituents of 

The active ingredients in chamomile are chamazulene, apigenin, and bisabolol.

https://inside.fei.org/sites/default/files/2018%20Equine%20Prohibited%20Substances%20List.pdf