They don't list the ingredients so I would suspect they are mainly sugar with a token amount of vit/ mins in, far better to use a red rockie or plain salt lick which they are unlikely to eat in one go and will provide a safer option, otherwise give a vit/ min supplement and add salt to a small feed each day to ensure she gets all she needs.
She has a salt lick in her stable. I am not convinced a supplement in the conventional sense would do the trick. I used to feed my previous horse Super Codlivine which is supposed to cover a broad spectrum, but my current horse is on a good mix of feed so don't feel she necessarily needs something adding to her feed everyday. I was hoping with the Likit product she would have it as and when like the salt lick. Will have to keep an eye on it though to make sure she doesn't have too much, not sure if there is sugar in it.
I found a bit more info and the main ingredient is, as I thought, sugar so the horse will love it but it will not be a healthy option, I would just add some salt to the feed as she is probably not getting enough from the lick.