Does Naf Shake relief actually work?

I have a gelding that was similar. We now turn him out and ride him in a full face net and he never shakes at all. I do also put sun block on his nose though, just in case the net moves. I try to make sure it gets up his nostrils to protect the pink skin, as that's where he burns the worst. A net will last forever and you can sell it on if it doesn't work for her. Try that before putting a chemical you're unsure about into your horse's system.