You’ve seen that MSM (Methylsulfonylmethane) is an ingredient in many joint supplements. But what does it really do? And how can it help your horse?
MSM is a potent anti-inflammatory. However, its role extends far beyond that. This article discusses some of those roles.
◆︎ MSM for joint support
MSM is well-known for supporting horses with stiffness due to arthritis. It is commonly paired with glucosamine, chondroitin sulfate, and hyaluronic acid. It’s been used for decades for joint support. Its main mechanism of action within the joint is to reduce the amount of inflammation. By doing so, it does more than just temporarily relieve pain. It also reduces the number of molecules that cause damage within the joint.
Best when paired with glucosamine, chondroitin sulfate, hyaluronic acid (HA), and/or Mov-Ease.
◆︎ MSM for respiratory support
Many horses have breathing issues from airborne particles. This is common with spring pollen, dust, and smoke particles from wild fires. MSM helps blunt the cellular response to the inflammatory cytokine triggers. This helps minimizes the degranulation of mast cells which release histamine, which contribute to the respiratory issues.
Best when paired with spirulina, quercetin, chondroitin sulfate, or jiaogulan.
◆︎ MSM for eNOS support
In a previous newsletter, available here, we talked about the importance of eNOS. In a nutshell, eNOS is the enzyme that converts L-arginine to nitric oxide. This causes smooth muscle dilation within the blood vessels. It’s important for vascular tone. This is especially important for respiratory health, as well as hoof health. MSM is protective of eNOS in that it helps eNOS remain bound to BH4.
Best when paired with jiaogulan, Mov-Ease, quercetin, or resveratrol.
◆︎ MSM for muscular recovery
High-intensity exercise can cause micro-trauma to muscle fibers due to the oxidative stress of exercise outpacing the antioxidant activity of the horse. Studies demonstrate that performance horses supplemented with MSM exhibit less post-exercise muscle soreness and lower concentrations of serum biomarkers associated with muscle damage.
Caution must be used for horses that are competing. Please review the prohibited substance list for your organization.
◆︎ Practical considerations
MSM is rapidly absorbed in the horse. But it is also excreted readily in the urine. To achieve the best results with MSM, it is necessary to supplement it daily. MSM works at the level of enzyme transcription. As such, you may not see a difference in your horse until 3-4 weeks of daily administration. Additionally, when you stop giving MSM to your horse, the inflammatory cytokines will return to the original state within 3-5 days.
◆︎ Consult your veterinarian
If you have issues that nutraceuticals do not help, please consult your veterinarian. He/she will be able to give you a diagnosis and treatment plan to help your horse.
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Disclaimer: Statements regarding dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease or health condition.
©Joan Kulifay, MSc. 2026