Choosing the Best Horse Calmer

Finding the best horse calmer can seem like a minefield. There are many calming ingredients (often listed under different names), a variance in quality, and what is best for one horse may not work for another. A basic understanding of the primary ingredients will help you to choose your horse calmer wisely.

Magnesium Calmers

Magnesium is a staple of horse calmers and certainly the most supported calming ingredient, both scientifically and anecdotally. There is a well-established link between magnesium and behaviour. It supports against stress and helps to maintain normal nerve transmission.

Because magnesium is an essential dietary component and very safe to feed (one of the few calming ingredients that has been well tested in horses), magnesium would usually be the first port of call when looking to help your horse with any stressful behaviour.

Products vary a great deal in quality; magnesium oxide being the cheapest but least well absorbed. For the best result, ensure that your magnesium horse calmer uses high quality, bio-available magnesium from a trusted manufacturer.


Herbal Horse Calmers

There are many plant extracts used and it is difficult to highlight any as the best horse calmer. Considering the lack of equine research it is reasonable to question whether you believe that the extract could help you (consider also that your horse will not receive the same placebo benefit). Then check the extract quality and that the feeding rate is sufficient for a horse.

Valerian is the most likely to help calm your horse but it is banned under competition rules. It may be useful outside of competition, when a drowsy action is acceptable, but not all horses will be responsive to supplementation.

You should also consider potential side effects. Confusion, dizziness, nausea and gastro-intestinal irritation are listed (in humans) as possible side effects of some the herbal extracts often found in horse calmers.


Amino Compounds - the confusing Ts

L-tryptophan is an essential amino-acid that contributes to the synthesis of serotonin, a neurotransmitter often referred to as a ‘mood hormone’. L-Tryptophan lost some favour after a research paper suggested that it may actually increase excitability in horses.  Horse calmers are now more likely to boast of L-tyrosine or L-theanine, although they have actually been used for many years.

L-tyrosine is similar to L-tryptophan in the respect that it is an amino acid associated with the synthesis of neurotransmitter substances.  It is present in the diet and can also be synthesised by the body, so there seems little benefit to daily supplementation. The appeal is that, during a time of acute stress, supplementing L-tyrosine may aid cognitive function (memory and learning) by delaying the depletion of neurotransmitters. It is a bit of a leap to apply this to behavioural problems in horses, particularly as feeding levels tend to be very low in horse calmers.

L-theanine is different in that it is non-dietary; it is not a required nutrient. It is actually an extract of green and black tea, therefore belonging with the herbal extracts.  L-theanine is reputed to aid relaxation. Some claims are made about cognition but these are more likely to be attributable to the combination with caffeine (as naturally exists in tea).



Found in very few horse calmers, casein is a protein rich substance derived from cows’ milk. Certain peptides found in casein are reputed to reduce anxiety and improve sleep; advertisers will often liken this to the effects of suckling. The amount contained in horse calmers is typically very low compared to that recommended for human supplementation.


Other Ingredients found in Horse Calmers

Many other vitamins and minerals may be present but they are unlikely to contribute meaningfully as a calmer. Keep this in mind when looking for the best calmer for your horse, it is easy to waste money looking at inconsequential differences.


B Vitamins

B-Vitamins are nutrients often associated with functions of the nerves and energy metabolism. The best candidates for your horse calmer are B6 (pyridoxine) which works in synergy with magnesium, and B1 (thiamine) which is thought to help with premenstrual syndrome.

Unlike us, horses gain their B-Vitamins from bacterial fermentation in the hindgut. They may still be supplemented as generally healthful, but are unlikely to calm.


Yeast and Digestive Additives

Many horse calmers contain yeast for hindgut stability. This is generally intended to help protect the hindgut from disturbance caused by stress, rather than with the expectation of calming. Some horse calmers do make claims about reducing butterflies but there is no logic to this. In any instance, a high quality digestive supplement would be needed in order to help stabilise the hindgut. This could also help reduce behaviours associated with discomfort and irritability (but is unlikely to help generally sharp or excitable behaviour).


Ant-Acids (e.g. Calcium Carbonate) and Gastric Additives

Gastric discomfort is certainly associated with ill behaviour and should be considered. However, your horse calmer will not contain appropriate levels of quality ingredients. A better approach would be to choose a high quality gastric supplement and assess any improvement independently. You may need to also consider veterinary treatment and management changes.


Calm without compromise...

Finding the best calmer for your horse can be a useful tool to help manage stressful and sharp behaviour and even to aid performance.

We love our horses as much as you do. If you are considering a calmer, we believe that the only place to start is with an essential nutrient that has a known association with behaviour and a clear mechanism of action. This is why our calmer uses patent protected MAH® magnesium, and no drowsy or compromising ingredients.

Nupafeed’s renowned MAH® Horse Calmer has been trusted by equestrian professionals for nearly thirty years. It has been pharmaceutically developed off the back of decades of research and is fully compliant with all competition rules.

Whether you are struggling with a new horse at home or trying to perfect a dressage test, we are here to help with all the advice you could need.

Nupafeed MAH Liquid Magnesium Horse Calmer 1ltr

Daily Calmer for Horses

MAH® Liquid is our daily calmer for horses. Use at home for sharp, spooky or aggressive horses, moving yards, box rest, breaking etc.


Instant Calmer for Horses

MAH®  is also available in concentrated form for targeted calming. Use on their own or in conjunction with the daily calmer for competition, travel, lessons etc.

In need of some expert, friendly advice?

If you have any questions or would like more information, please get in touch.


More Articles

L-Carnitine for Horses

21st March 2023

L-Carnitine for Horses

20th March 2023

Complete Skin and Coat Supplement for Horses

The Best Supplements for Stabled Horses

21st October 2022

Help for Stabled Horses

“Helawi Agapantha Blue lost so much energy at South Suffolk that he wouldn’t even trot up, so we decided to try Nupafeed Staying Power. Our next show was Herts County, Blue went beautifully and won the youngstock Shetland class. Staying […]