have a mare that stays on edge most days.  some days she is nice, quiet and relaxed and others snorty about every little thing.  not a mean bone in her.  looking for a supplement that maybe just feed daily.  dont want to keep up with injectable meds

I would start by evaluating her diet. If she is getting any molasses or soy. Start by eliminating those and she how she responds. 

I put my nervous nelly on mare magic and she is like night and day.  I've never used any sort of calming supplement and this is the only one I had really heard of, so I started with it and am happy with the results so far.

When I was in college years ago the university had a mare like this donated to them. She was like that until they discovered she had a massive ovary. I forget what they did about it however she was reasonable after they corrected the issue. I rode her for them and as long as you worked her regularly she was extremely gentle to ride. All the witchy behavior stopped. I would have a vet check her and maybe put her on a specific diet .

I will only use Mushroom Matrix ECP. I used it on a filly I rehabbed that was on a long term stall rest. I've used it on stallions during breeding season. It makes them focus, and not dead head at all

Relax pellets by oxygen. Great product & it works. No I don't sell it. 

I second the relax pellets. They really help my mare. 

You do not say what this mare's diet is. This can be a big factor in blood sugar levels that can give mood swings like you are describing. That is the best place to start, because, if that is the issue, additional supplements will be a waste of money.

A good magnesium supplement can help many horses! Quite inexpensive as well!

My mares problems stemmed from horrible trainers who aced her , etc. They lied to us & when I brought her home I took her to the vet & had her scoped & she was full of ulcers & bots. I about died. So no, my mares problems have nothing to do with diet. Her problems have to do with some so called trainers who did this to her. I took her to Amberley Snyders clinic & she said, your horse has serious anxiaty & she did thanks to these sorry bastards who did this to her. So with her issues, I can say the oxygen relax pellets did help her. Her problems have nothing to do with diet 

It's true that your horse got her anxiety from bad trainers and poor health However....... while your working through those issues it would be good to evaluate diet. Just as an example..... if your trying to retrain her and she is on 12 pounds of sweet feed , that makes your training a lot harder. Not saying that's what's happening with your horse . Just as an example. 

I'm a big believer in the diet being evaluated first and foremost when trying to calm a horse or help them relax more. I think it gets overlooked in a lot of situations and could be an easy fix instead of adding a calming supplement in SOME cases. 

As far as my mare goes, she is on a good diet. Bermuda hay & triple crown & she only gets 3 cups of t.c. 

^^^^ THIS^^^^ So much starts with the diet they are on!  High protein makes my horses crazy and they are all chill any other time... I have to stay under 12% with what I feed them.. otherwise I might as well give them a huge monster drink and king size candy bar and see how they react...

I had a mare who was very sweet but anxious and Via Calm worked great. Just took the edge off a little. 

Redmond Daily Gold Stress Relief. I couldn't believe something that simple and cheap made such a difference!