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For horses · Dec 21, 2012

Devil’s claw, MSM and glucosamine are the smarter answer to equine joint pain

The research behind these three natural compounds is genuinely solid, and when you put them together, they tackle equine joint pain through complementary, well-characterised mechanisms that make good biochemical sense.

Dapple grey horse moving freely in a misty grass paddock — devil's claw, MSM and glucosamine for equine joint support

By Beryl Shuttleworth, BSc Hons Biochem

Last reviewed: 2026-06-12

Three natural ingredients I keep coming back to for horse joint support are devil’s claw (*Harpagophytum procumbens*), MSM, and glucosamine, and there’s solid reasoning behind each one. Devil’s claw’s iridoid glycosides are genuinely analgesic and anti-inflammatory. MSM is absorbed quickly by the small intestine, and its sulphur gets incorporated directly into tissue proteins, feeding several key metabolic pathways. Glucosamine, for its part, supplies the raw building blocks for cartilage glycosaminoglycans, and in equine studies it’s produced clinically measurable reductions in lameness.

Devil’s Claw doesn’t work when fed orally, it needs to be injected to do anything

I hear this one regularly, usually from vets who’ve read the early injection studies and jumped to the wrong conclusion. The thinking goes: injected Devil’s Claw (Harpagophytum procumbens) produces stronger effects than oral dosing, therefore oral must be pointless. It’s a leap the evidence simply doesn’t support.

What the research is actually telling us is a mechanism story, not a failure story. The iridoid glycosides, harpagoside and harpagide, need their glycosidic bonds hydrolysed before they can get to work as anti-inflammatories. Stomach acid can partially break down these compounds during oral transit making them inactive, so yes, bioavailability is lower by mouth than by injection [4]. That’s a pharmacokinetic reality, and a pretty ordinary one at that, it’s not unique to Devil’s Claw, and it’s certainly not a reason to write the herb off. The logical response is to adjust the dose upward to compensate, which is exactly what we do with a great many conventional drugs.

The clinical evidence is reassuring on this front. A randomised controlled trial in 40 horses given Harpagophytum orally for eight weeks found significant subjective improvements in locomotor abnormalities, and those effects were still detectable at a 16-week follow-up [2]. A systematic review of Devil’s Claw for osteoarthritis, acknowledging that plenty of the published trials had methodological shortcomings, concluded that the higher-quality studies pointed to genuine pain reduction, with a much more modest risk profile than NSAIDs [3]. On top of that, pharmacokinetic work specifically in horses has confirmed that harpagoside from an oral extract is absorbed and measurable in circulation [1].

So yes, oral bioavailability is lower than injectable. That’s just how this herb works by mouth. Dose accordingly, and it does the job.

How devil’s claw, MSM and glucosamine work on equine joints

Let’s start with the plant, because Devil’s Claw (Harpagophytum procumbens) is doing a lot more than most people realise. It isn’t just one active compound, it’s a whole family of them: iridoid glycosides (harpagoside, harpagide, procumbide), phenolic glycosides (acteoside, isoacteoside), and triterpenoids. That breadth matters, because the anti-inflammatory and analgesic effects come from the full extract working together, not a single isolated molecule.

There’s an important nuance worth knowing here. The iridoid glycosides, harpagoside and harpagide in particular, need their glycosidic bonds cleaved by the enzyme β-glucosidase before they become biologically active. Stomach acid can partially break them down before that enzyme gets a chance, which is why oral dosing needs to be generous to achieve meaningful tissue levels.

MSM (methylsulfonylmethane) is a sulphur-based compound, and it’s one of those ingredients that looks simple on the label but turns out to be quietly useful once you follow what happens to it in the body. It’s rapidly absorbed in the small intestine, distributes into tissues, and the sulphur it carries gets incorporated into tissue proteins over time. Sulphur itself is involved in protein synthesis, carbohydrate metabolism, and detoxification, it’s not sitting idle. Clinical trial evidence supports MSM for reducing the pain, stiffness, and swelling of osteoarthritis, and it shows clear anti-inflammatory properties, though exactly how it produces those effects is still being worked out.

Glucosamine is the structural building block your horse’s body uses to make glycosaminoglycans, the long-chain molecules that form the backbone of cartilage and connective tissue. In vitro studies show it interacts with joint cells and can potentially stimulate proteoglycan synthesis. The honest caveat here is that plasma concentrations achieved in those in vitro studies are often far higher than what oral dosing realistically delivers, so the cartilage-rebuilding story is stronger in the lab than it is in the field. That said, equine studies do show clinical improvements in lameness scores, which suggests something useful is happening even if the underlying cartilage biochemistry isn’t fully normalised.

How to use Devil’s Claw, MSM and glucosamine sulphate for equine joint support

Devil’s Claw (Harpagophytum procumbens)

If you want a well-designed equine trial to point to, the one that stands out used an aqueous Harpagophytum extract fed for 8 weeks. Subjective assessments of locomotor abnormalities improved significantly, and here’s the bit I find really compelling, that improvement was still there at the 16-week follow-up, long after supplementation had stopped. That carry-over benefit tells you something meaningful about how this herb works.

On the safety front, pharmacokinetic work in horses confirms it’s well tolerated orally, with no clinically detectable gastrointestinal irritation in dosing studies. That’s reassuring, because it’s a herb I’ve been recommending for years and the formal data backs up what I’ve seen in practice.

MSM (methylsulfonylmethane)

MSM is absorbed rapidly by the small intestine, and the sulphur moiety accumulates in tissues over time, incorporating into proteins and feeding into key metabolic pathways including protein synthesis and detoxification. Clinical trials in osteoarthritis models show reductions in pain, stiffness and swelling, a solid result for a supplement that often gets dismissed as basic. Because tissue incorporation takes time, consistent daily use makes far more sense than dipping in and out, though I’ll be honest, the research pool doesn’t pin down a specific minimum duration for horses in particular.

Glucosamine

In vitro equine cartilage studies show that glucosamine and chondroitin sulphate together inhibit cytokine-driven cartilage degradation more effectively than either compound alone, so combining them isn’t just marketing, it’s the rational biochemical choice. A 2022 experimental equine osteoarthritis study confirmed clinical modulation of lameness symptoms with oral glucosamine and chondroitin sulphate, which is encouraging. That said, the treatment didn’t fully arrest the underlying catabolic process in cartilage, and I think it’s important to be straight with people about that. These are supportive tools, not a cure, and anyone telling you otherwise is overselling.

Combining all three

The mechanisms genuinely complement each other, anti-inflammatory and analgesic action from Devil’s Claw, sulphur substrate provision from MSM, and structural cartilage support from glucosamine. That’s why feeding all three together daily is the approach I recommend, rather than rotating them or picking one. The 8-week equine trial gives you a sensible minimum timeframe to assess whether your horse is responding before you draw any conclusions.

What we’d recommend


Herbal Horse Rejuven Mix

Devil’s Claw, MSM, and glucosamine working together, less joint pain, better cartilage support.

See the product

Frequently asked questions

Does devil’s claw actually reduce pain and inflammation in horses?

The short answer is yes, and the evidence is more solid than you might expect. A randomised controlled trial gave 40 horses 10 g daily of devil’s claw (Harpagophytum procumbens) extract for eight weeks and found significant subjective improvements in locomotor abnormalities, with effects still measurable at 16 weeks. Human osteoarthritis research backs this up too, higher-quality trials consistently point to meaningful pain reduction. It isn’t a silver bullet, but the clinical signal is real and worth taking seriously.

How does MSM work for joint pain in horses?

MSM (methylsulphonylmethane) is a sulphur-based compound that gets absorbed rapidly in the small intestine, with its sulphur becoming incorporated into tissue proteins over time. Sulphur has a hand in protein synthesis, carbohydrate metabolism, and detoxification, so it’s doing quite a lot behind the scenes. Clinical trials in osteoarthritis have shown MSM reduces pain, stiffness, and swelling across multiple measures. The leading thinking is that it corrects a dietary sulphur shortfall and supplies the raw material your horse’s connective tissue actually needs.

Is glucosamine sulphate or glucosamine hydrochloride better for horses?

I’d go with glucosamine sulphate every time. It has better demonstrated oral bioavailability than the hydrochloride form, and as a direct building block of glycosaminoglycans, the structural components of cartilage and connective tissue, it’s simply the more logical choice when you’re trying to support joint integrity. If the goal is getting useful amounts where they’re needed, starting with the form that absorbs better makes sense.

Are there safety concerns with giving devil’s claw to horses long-term?

Reassuringly, the pharmacokinetic data we have from horses is quite positive. Oral dosing studies found devil’s claw (Harpagophytum procumbens) extract to be safe and well-tolerated, with no clinically detectable gastrointestinal irritation observed. That matters, because gut sensitivity is often the first thing that rules out a supplement for long-term use in horses. So far, the safety profile looks favourable, though as with any long-term supplement, it’s worth monitoring the individual animal.

Sources

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