Pure Magnesium Citrate 8 ounce container with 75 servings

Magnesium Citrate

  • Dosage:

    Loading dosage: 2 scoops twice a day for 7 days

    Maintenance dosage: 1 - 3 gram scoop included, 1 scoop per day

    Magnesium Citrate: The Mineral Superhero

    Very few people are aware of the enormous role magnesium citrate plays in a horse’s body. After oxygen, water, and basic food, magnesium citrate may be the most important element needed to maintain health. It is vitally important, yet hardly known. Magnesium citrate is by far the most important mineral, regulating over 325 enzymes in the body.  Magnesium citrate supplementation has been shown to improve performance and allow human athletes to reach exhaustion later in their exercise routine. It increases oxygen delivery to muscle tissue; it promotes muscle strength, endurance and relaxation. Magnesium citrate also activates enzymes necessary for the metabolism of carbohydrates and amino acids which lead to protein synthesis.

    Magnesium Citrate is often the most neglected mineral in horse feeds. Spring grass is typically deficient in magnesium due to the fast growth rate and at this time of year many horses seem hotter and more difficult to ride. Owners often attribute this to too many carbohydrates in the grass.  While this may be part of the story, what is often overlooked is that these horses may be deficient in magnesium Citrate.  Magnesium Citrate deficiency has varying effects on the horse population.  Some horses do not suffer any signs while others are almost unrideable due to their apparent silliness and hyperactivity.  Adding magnesium citrate to their diet may have a dramatic calming effect.  To understand why magnesium citrate affects the horse in a calming manner, it is important to know what is happening in your horse’s body on a cellular level when there is a magnesium citrate shortfall.

    Calcium and magnesium work closely with each other.  Calcium needs magnesium to assimilate properly however magnesium citrate does not need calcium.  Calcium is in charge of contracting the muscle and magnesium citrate looks after the relaxation or release of the muscle much like a gas pedal and a clutch work together.  When a muscle cell is triggered, the cell membrane opens, letting calcium in and raising the calcium level in the cell setting off a reaction and the muscle contracts.  When the contraction is done, the magnesium inside the cell helps to push the calcium back out of the cell releasing the contraction.  This happens very rapidly.  When there is not enough magnesium citrate in the cell, calcium can leak back in causing a stimulatory effect and the muscle cannot completely relax. This can put the body into a continually stressed state.  Low magnesium makes nerve endings hypersensitive thus exacerbating pain and noise. Magnesium Citrate is required for proper nerve and muscle function.

    Horses with magnesium deficiency may have all or only a few of these signs so it is important be aware of them.  They may be borderline and only exhibit signs during competition or stress.  For instance, horses with magnesium deficiency often have very sore tight backs in spite of excellent saddles and pad, proper fit, conditioning and training.  They don’t respond well to chiropractic adjustments and massages or these treatments don’t last more than a couple days and the tension and soreness return.  They often resent or even act afraid of being touched leading the owner to ask themselves, ‘Is someone abusing this horse when I am not around?’  Their response to outside stimuli is over reactive and they tend to become fractious, worried, fearful or resistant to training.

    Other signs:

    • Unable to relax physically or mentally
    • Muscle tremors, twitches, flinching skin, or all over body trembling especially after exertion (not related to outside temp)
    • Body tension
    • Does not tolerate long periods of work– often becoming more excited instead of working down
    • Has difficulty with collection or picking his back up under saddle, moves hollow
    • Random spooking, running through the bridle, inconsistent from one ride to the next
    • Angry about being brushed, blanketed or touched or palpated on either side of spine
    • History of tying up
    • Fatigue
    • Painful heats in mares
    • Bucking or rearing 20-30 minutes into a ride for no apparent reason
    • Requires long periods of lunging before being able to focus on work
    • Would be described as ‘thin skinned’ or over sensitive to sound or movement
    • Massage and chiropractic adjustments do not have lasting effects
    • Teeth grinding
    • Irregular heartbeat or pounding heart- endurance horses often experience this at vet checks

    Magnesium Citrate is assimilated quickly in times of stress, such as traveling or heavy training.  Horses lose magnesium through sweat and urine.  Many performance horses can become deficient as the season progresses as they are using the available magnesium more rapidly due to stress, travel and competition. Horses with low magnesium status will often crave salt, which exacerbates the shortfall. 

    These horses are often difficult to work with, so riders tend to over exercise in an effort to manage behavior.  They are worked harder and for longer periods of time in an effort to wear them down which only adds to the shortfall thus creating a vicious cycle.  This causes more sweating and muscle cramping while contributing to fatigue, soreness, post competition pain and a negative association to work.  Behavior gets worse with more work and exposure to stress, not better. Subsequently, horses begin to resent the show arena often developing gate issues.

    There are many factors that affect magnesium absorption and utilization.   Working horses require 10-30% more magnesium for light to moderate exercise, respectively, due to sweat losses.  Horses who sweat heavily will lose magnesium at a more rapid rate as well.


    Magnesium toxicity is rare because excess is naturally excreted.   Magnesium Citrate should be split between morning and evening feedings to increase absorption and decrease its occasional laxative effects. Once a horse becomes low on magnesium, it is very difficult for them to catch up without supplementation.

    What kind of magnesium should I use?  

    There are injectables, oral supplements and transdermal applications.  The most popular is oral magnesium oxide and the least bioavailable form of magnesium.  Some horses do not like the powdery texture so picky eaters may turn up their noses to it.  It can also act as a buffer in the horse’s stomach which can help horses who tend to develop ulcers.  There are many oral forms of magnesium. 

    Magnesium Citrate is highly absorbable, bioavailable and has the least potential laxative effect.   Horse owners need to be aware that magnesium is in different forms such as citrate, oxide, ascorbate, which is the secondary ion.  Horse owners should avoid magnesium sulfate because of its laxative effect. Horses showing severe signs of deficiency respond may require more. Every horse is different and will have its own individual maintenance dose. This will also fluctuate depending on times of stress, showing, weather and pasture content. When signs of deficiency begin to subside, the dosage can be tapered off.

    How do you know how much magnesium your horse is getting?  It’s very difficult without analyzing every bale of hay.  Many feed supplements only give you a percentage of mineral content, not a gram total.  One thing you can do to insure your horse is not deficient is to familiarize yourself with the signs of possible deficiencies in your horse.  If you think you may have a shortfall, it’s a very safe mineral to give in any case. Make sure your horse has access to water.


    Disclaimer: The information in this article in not intended to replace a one-on-one relationship with a qualified healthcare professional and is not intended as medical advice. It is intended as a sharing of knowledge and information. We encourage you to make your own health care decision for your horse based upon your own research and in partnership with a qualified veterinarian.