I've had very good experiences with any kind of magnesium supplement in combination with vitamin B

Smartpak Flex or Dumor joint. I use dumor joint for my schoolmaster and it's helped her a lot. Heard many great reviews for smartpak flex

Hello Freya,

There is product called Becool from the french brand @ravene, it is a solution made from plants and leaves that help calm your horse and regulate his anxiety. It is a non doping porduct so your are free to use it in competition.

Hope it helps!