MSM for Your Horse: Effects, Dosage & How Long to Feed It

We are Katja and Andrés from nuvallo. Having spent over 20 years at the feed trough with our own horses, we know the uncertainties surrounding joint feeding from first-hand experience. In this article, we explain clearly what MSM is, what a sensible dosage looks like, how long you should feed it, and what the research actually reveals.

What exactly is MSM?

MSM stands for methylsulfonylmethane, an organic sulphur compound that occurs naturally in plants, soil, and even the horse's own body.

Sulphur might not sound particularly spectacular at first. However, after calcium and phosphorus, it is the third most abundant mineral in your horse's body, and it has a far more important role than most people realise: sulphur is found in the amino acids methionine and cysteine, and without these, the body can produce neither collagen nor keratin. That means: no stable cartilage, no elastic tendons and ligaments, no resilient hoof horn, and no glossy coat.

Imagine sulphur as the mortar that holds the bricks of a house together. The bricks themselves – collagen, glucosamine, and keratin – are essential. But without the mortar, nothing stays in place.

Why can supplementation be beneficial? Because the sulphur content in basic forage fluctuates significantly depending on the soil, fertilisation, and harvest time. On top of that, older horses, sports horses under high physical strain, and horses with early-stage joint issues have an increased requirement. MSM provides this sulphur in a form that the body can easily absorb and utilise.

The effects of MSM in horses: What does science say?

The most important point first: the research on MSM is promising, but not as definitive as many manufacturers make it out to be. We are therefore taking a close look at what has been proven in the laboratory, what has been studied in live horses, and what this means in practice.

What has been proven in the laboratory

In cell studies, MSM demonstrates two main effects that are relevant for joints. First, anti-inflammatory action: research teams at Seoul National University (Kim et al., 2009) and Kangwon National University (Ahn et al., 2015) independently showed that MSM inhibits the NF-κB signalling pathway, a central switch for inflammatory responses. Specifically, MSM reduces the production of inflammatory messengers such as IL-6 and TNF-α. At the Ludwig Boltzmann Institute for Rheumatology in Vienna (Kloesch et al., 2011), this effect was even confirmed directly on human cartilage cells. Second, antioxidant protection: MSM supports the production of glutathione, the body's most important endogenous antioxidant, and can thereby reduce oxidative stress, which increases during intense exercise and in old age.

Important for context: laboratory results cannot be automatically transferred to a live horse. The concentrations in cell studies are often significantly higher than what actually reaches the bloodstream through feeding. However, they provide a solid biological foundation for why MSM can be effective.

What has been studied in live horses

The most well-known study comes from Marañón and colleagues (2008, Acta Veterinaria Scandinavica). They examined 24 showjumpers during a competition in Spain. The horses received MSM for about six weeks and subsequently showed significantly less oxidative stress after exercise – meaning lower levels of lipid peroxidation and nitric oxide, alongside higher glutathione levels. The effect was most pronounced in the group that received MSM together with vitamin C.

Another investigation involving 30 Standardbred racehorses (Riegel, 2001) compared 10 g and 20 g of MSM per day over eight weeks with a control group and found lower markers of muscle damage, improved training times, and, according to trainers, a better coat and stronger hooves. To be entirely honest, it must be noted that this study was only published as a conference paper and was not peer-reviewed, so its results should be viewed with caution.

A recent study by Barshick et al. (2025, Animals) examined 10 Thoroughbreds that received 21 g of MSM per day over 30 days. Muscle biopsies showed improved anti-inflammatory gene expression post-exercise, an interesting piece of evidence that MSM also reaches the horse's body on a molecular level. Additionally, a large meta-analysis by Liu et al. (2018, British Journal of Sports Medicine) evaluated 69 studies on nutritional supplements for osteoarthritis in humans and identified MSM as one of six supplements with a statistically significant reduction in pain.

An honest conclusion

MSM is not a miracle cure. The research on horses is based on small sample sizes and short timeframes; a large-scale, peer-reviewed dose-response study on horses does not yet exist. However, the biological foundation is solid: sulphur is needed to build cartilage, tendons, and connective tissue, the anti-inflammatory effect has been confirmed in several independent laboratories, and existing equine studies consistently show positive trends with no serious side effects. So, while MSM is not a panacea, it is a highly beneficial building block. And it becomes particularly valuable when it does not have to work alone.

MSM dosage for horses: How much does your horse really need?

In the published equine studies, dosages ranged between 8 mg/kg of body weight (Marañón et al.) and 21 g per day (Barshick et al.). The most common recommendation derived from this is around 10 to 20 g of MSM per day for a 500 kg horse, provided MSM is given as a pure, single active ingredient.

To start with, many experts recommend an initial loading phase: feed double the amount for the first two to four weeks, then reduce it to the normal maintenance dose. This makes perfect sense because MSM does not offer an immediate effect. Experience shows that it takes a minimum of 8 to 12 weeks of consistent feeding until a reliable picture emerges. Many report the first changes after four to six weeks, but patience is absolutely key here.

Now it gets interesting: if MSM is used in a well-balanced combination product – meaning together with glucosamine, collagen, and hyaluronic acid – the individual dosage can be set lower without losing effectiveness. We will explain exactly why in a moment.

What you should look out for when buying: many joint products list MSM in their ingredients without revealing how much is actually included. EU Regulation 767/2009 permits this, as manufacturers only have to list ingredients in descending order by weight; providing specific quantities per kilogram is entirely voluntary. Therefore, if a product simply says "MSM" but lacks a mg/kg figure, you genuinely do not know if your horse is receiving an effective dose or just a trace amount for advertising purposes. As a consumer, you should actively look for products that fully disclose their active ingredient quantities.

Why MSM alone is often not enough: The power of combination

Joints are complex systems. Cartilage, synovial fluid, ligaments, and tendons each have different requirements, which is exactly why it makes sense to combine active ingredients that target different areas. Imagine a joint like a house again:

• Glucosamine (50,000 mg/kg in nuvallo move) is the building material for the filling. The body converts it into glycosaminoglycans, the molecules that make cartilage elastic and resilient. In this process, MSM provides the sulphur the body needs to actually build cartilage from glucosamine – two keys for the same lock.
• Collagen (85,000 mg/kg in nuvallo move) is the framework. It gives connective tissue, tendons, and cartilage their structure and tensile strength. While MSM and glucosamine provide the filling, collagen ensures that the whole structure holds together.
• Hyaluronic acid (5,000 mg/kg in nuvallo move) is the lubricant. As the main component of synovial fluid, it ensures smooth movement. In-vitro studies from Ohio State University (Kilborne et al., 2017) demonstrate that hyaluronic acid has a stronger anti-inflammatory effect in combination with glucosamine than on its own – a clear sign of true synergy.
• MSM (75,000 mg/kg in nuvallo move) supplies the organic sulphur, has an anti-inflammatory effect, and protects the tissue from oxidative stress.

The effectiveness of combination products is demonstrated by a randomised, placebo-controlled crossover study from the Animal Health Trust in Newmarket (Murray et al., Equine Veterinary Journal). Over 21 days, 24 horses – 71% of which exhibited mild to moderate lameness – received either a combined supplement of glucosamine, chondroitin sulphate, and MSM, or a placebo. The horses taking the supplement showed significantly lower degrees of lameness and better mobility. Because each horse served as its own control, this result is particularly compelling.

While it is impossible to deduce from a combination study exactly how much each individual active ingredient contributes, the overall picture is clear: a well-balanced combination product does not require extreme individual doses because the active ingredients complement each other perfectly. This is precisely the principle we use in nuvallo move. A daily ration (6 snacks for a 500 kg horse) transparently provides 2,250 mg of MSM, 1,500 mg of glucosamine, 2,550 mg of collagen, and 150 mg of hyaluronic acid.

Feeding MSM to horses: The biggest problem is not the active ingredient

Now we come to the point that hardly anyone talks about, yet it makes the biggest difference in practice.

MSM has a slightly bitter, sulphurous taste. Barely noticeable to us, but a real issue for a horse's sensitive nose. And this is exactly where the dilemma begins. You buy a high-quality joint powder, read the dosage recommendation, and conscientiously mix the correct amount into the feed. And then? Your horse sniffs it, pushes the feed around, eats half, and leaves the rest. Or they eat everything, but a fine, slightly sticky layer remains at the bottom of the trough – precisely the layer where the powder has settled.

You know the usual tricks: introduce it slowly, dampen it, mix it with sugar beet pulp, or stir it into apple sauce. Sometimes this works, sometimes only for a while, and sometimes nothing helps at all because your horse is simply cleverer than any trick. The frustrating part is not the effort involved, but the uncertainty: has the horse really ingested the full dose? Or is the expensive supplement just disappearing into the bottom of the trough, leaving you paying for a clear conscience rather than a real effect? We know this feeling well; we have stood at the feed trough often enough and asked ourselves exactly the same question.

Why we have done away with powder

After years with our own horses and speaking with hundreds of horse owners, we eventually turned the question around. Not "How do we make a better powder?", but "How do we ensure that every horse reliably takes in the full dose?" The answer was nuvallo move, a functional joint snack that is fed directly from the hand.

Each snack contains a defined amount of glucosamine, collagen, MSM, and hyaluronic acid. Six snacks per day make up the daily ration for a 500 kg horse. No weighing, no dust, no mixing. The horse cannot sort anything out because the active ingredients are baked right into the snack rather than sprinkled on top. And instead of stress at the feed trough, your horse experiences feeding as what it should be: a reward. The base is free from wheat and corn, relying on linseed cake and rice bran, making it suitable even for horses with sensitive stomachs. Natural ingredients like banana, apple, and carob ensure a level of acceptance that no powder could ever offer.

Because, ultimately, the best supplement is not the one with the longest ingredient list or the highest lab values. It is the one that actually ends up inside the horse.

Frequently asked questions about MSM for horses

How long does it take for MSM to work in horses?

The first noticeable effects typically appear after 2 to 4 weeks of consistent daily feeding. Riders often report more fluid movement, a better warming-up phase, and faster recovery after training. However, for a fair assessment of the overall effect, you should feed it continuously for at least 8 to 12 weeks, as the metabolism of connective tissue and cartilage is slow. Daily administration is important because skipping days on the weekend or feeding it irregularly will significantly delay the effects.

When should you feed MSM?

MSM makes sense in several situations: during daily training to support recovery after exertion, particularly for sports and competition horses; in older horses to maintain mobility; as well as after operations or during box rest, when connective tissue is under particular demand during rehabilitation. The daily dose is best given in the morning or evening alongside hard feed – the key is consistency, not the exact time of day. During acute phases or at the beginning of a feeding programme, a double dose is recommended for the first 2 to 3 weeks to replenish the body's reserves.

What is MSM used for in horses?

MSM is not a medication and does not replace veterinary treatment following a diagnosis. As organic sulphur, it is an essential building block for connective tissue and supports the body's own inflammatory regulation. In practice, it is primarily used for the nutritional support of the musculoskeletal system: during high sporting exertion, to aid recovery after training, to maintain mobility in older horses, and generally to supply tendons, ligaments, and cartilage with sulphur. In cases of specific health problems, it is always best to discuss the feeding plan with your vet – MSM will then act as one component within the overall management strategy, rather than a standalone solution.