MSM (Methylsulfonylmethane) for Dogs: Joint Mobility & Inflammation Support

MSM – Multiple Gut-Organ Benefits for Dogs

Summary

Methylsulfonylmethane (MSM) is a naturally occurring organosulphur compound that provides one of the most bioavailable forms of dietary sulphur — the third most abundant mineral in the mammalian body and an essential structural component of cartilage, collagen, and connective tissue.¹ Sulphur is required for the synthesis of glycosaminoglycans (GAGs), the disulphide bonds that stabilise collagen architecture, and the production of glutathione — the body’s primary intracellular antioxidant.¹ In vitro studies demonstrate that MSM inhibits NF-κB inflammatory signalling in chondrocytes, reducing the expression of pro-inflammatory cytokines including IL-1β, IL-6, and TNF-α, while simultaneously suppressing COX-2 and iNOS expression.² In an accepted osteoarthritis animal model (STR/Ort mice), 13 weeks of oral MSM supplementation decreased cartilage surface degeneration in a dose-dependent manner.³ Multiple randomised, double-blind, placebo-controlled trials in human subjects with knee osteoarthritis have demonstrated that MSM significantly reduces pain and improves physical function compared to placebo.⁴˒⁵˒⁶ Emerging evidence also reveals that MSM supports intestinal barrier integrity — upregulating tight junction proteins (occludin, claudin-1, ZO-1) in epithelial cells challenged with inflammatory stimuli — and that the sulphur moiety of MSM is co-metabolised by the gut microbiome, establishing a functional connection between this joint-support compound and gut health.⁷˒⁸ Beyond joint and gut health, MSM demonstrates hepatoprotective effects through glutathione elevation, inhibits RANKL-induced osteoclastogenesis (bone resorption) via NF-κB and STAT3 suppression, and enhances mesenchymal stem cell chondrogenic commitment — positioning it as a compound with genuinely systemic, multi-axis activity.⁹˒¹⁰˒¹¹ Bonza includes MSM across three products: at 120 mg per chewy in Bounce Bioactive Bites, at 90 mg per chewy in Boost Bioactive Bites, and within Superfoods & Ancient Grains complete food.

Key Takeaways

• MSM is a naturally occurring organosulphur compound that provides bioavailable sulphur — an essential substrate for the synthesis of glycosaminoglycans, collagen cross-linking, and glutathione production, all of which are critical for cartilage integrity and antioxidant defence.¹
• In vitro, MSM inhibits NF-κB transcriptional activity in chondrocytes challenged with IL-1β, reducing the expression of COX-2, iNOS, and pro-inflammatory cytokines (IL-1β, IL-6, TNF-α), while also suppressing NLRP3 inflammasome activation by blocking mitochondrial ROS production.¹˒²
• In an accepted osteoarthritis animal model (STR/Ort mice), 13 weeks of oral MSM decreased cartilage surface degeneration in a dose-dependent manner at physiologically relevant doses, providing direct evidence of chondroprotective effects.³
• Three separate randomised, double-blind, placebo-controlled trials in human subjects with knee osteoarthritis demonstrated that oral MSM (2–6 g daily for 12–26 weeks) significantly reduced pain and improved physical function compared to placebo, with no serious adverse events reported.⁴˒⁵˒⁶
• MSM upregulates tight junction proteins (occludin, claudin-1, ZO-1) in intestinal epithelial cells challenged with LPS, protecting gut barrier function — and the sulphur moiety of MSM is co-metabolised by the gut microbiome, establishing a direct functional link between this joint supplement and the gut-joint axis.⁷˒⁸
• MSM demonstrates hepatoprotective effects in multiple animal models — increasing liver glutathione by 78% in mice and protecting against chemically induced liver injury — while also inhibiting osteoclast formation (bone resorption) via suppression of NF-κB and STAT3, suggesting broad gut-liver and gut-joint axis relevance.⁹˒¹⁰˒¹¹

In this guide:

• What Is MSM?
• Bioactive Compounds and How They Work
• Health Benefits for Dogs
• MSM and Gut Health
• Why Bonza Includes MSM
• Safety Profile
• How to Give MSM to Your Dog
• Dosage Guidelines
• Practical Considerations
• Frequently Asked Questions
• Related Reading
• References
• Editorial Information
• About the Author

What Is MSM?

Methylsulfonylmethane (MSM; chemical formula (CH₃)₂SO₂) is a naturally occurring organosulphur compound found in small quantities in fruits, vegetables, grains, and animal tissues. It is the oxidised metabolite of dimethyl sulphoxide (DMSO) and is part of the global sulphur cycle — produced when marine phytoplankton release dimethyl sulphide (DMS), which undergoes atmospheric oxidation to form DMSO and subsequently MSM.¹ These compounds return to earth in rainfall and are incorporated into the food chain through plants.

Sulphur is the third most abundant mineral in the mammalian body, representing approximately 0.3% of total body mass — a proportion five times greater than magnesium and forty times greater than iron.¹ It is present in every cell as a structural component of the amino acids methionine and cysteine, and is therefore essential for the synthesis of virtually all proteins. In the context of joint health, sulphur plays several indispensable roles: it provides the substrate for glycosaminoglycan (GAG) sulphation — the process that gives cartilage its characteristic negative charge, water-binding capacity, and compressive resistance; it forms the disulphide bonds that stabilise collagen’s triple-helix architecture; and it is the essential precursor for the synthesis of glutathione (GSH), the body’s primary intracellular antioxidant.¹

The relevance of sulphur to joint integrity is more than theoretical. Examinations of osteoarthritic cartilage have revealed sulphur concentrations less than one-third of those found in healthy cartilage tissue, illustrating the direct association between sulphur status and cartilage health.¹² MSM provides sulphur in a highly bioavailable, organic form. Absorption studies in mice using ³⁵S-labelled MSM have demonstrated that intestinal absorption of MSM is passive and non-saturable, with high capacity, and that the sulphur moiety is progressively incorporated into tissue proteins including serum proteins, liver tissue, and skeletal structures.⁸ Importantly, MSM also readily crosses the blood-brain barrier, distributing evenly throughout the brain — a property that distinguishes it from most dietary sulphur sources.¹

The therapeutic investigation of MSM began in the 1970s and 1980s, building on earlier work with DMSO at the Oregon Health Sciences University. Robert Herschler, a biochemist who studied MSM’s parent compound, filed the first patent for MSM as a dietary supplement in 1982.¹ MSM holds Generally Recognized As Safe (GRAS) status from the United States Food and Drug Administration (USDA) and has become one of the most widely used joint-support supplements in both human and veterinary medicine, used either as a standalone agent or — more commonly — in combination with glucosamine and chondroitin sulphate.¹

Bioactive Compounds and How They Work

Unlike multi-compound botanical supplements, MSM delivers a single bioactive molecule — methylsulfonylmethane itself — that exerts its effects through multiple complementary mechanisms, all ultimately deriving from its role as a bioavailable sulphur donor and its ability to modulate redox-sensitive transcription factors.

Sulphur Donation for Structural Proteins and Glutathione

MSM’s most fundamental function is providing bioavailable sulphur for the synthesis and maintenance of structural proteins and the body’s primary antioxidant defence system. Isotope-tracing studies in mice using ³⁵S-labelled MSM have demonstrated that the sulphur moiety from orally administered MSM is progressively incorporated into tissue proteins over time, with increasing ³⁵S accumulation detected in serum proteins, liver tissue, and other organs — and that gut bacteria play a critical role in this co-metabolism, converting MSM-derived sulphur into sulphur-containing amino acids.⁸

This sulphur supports the biosynthesis of methionine and cysteine — the sulphur-containing amino acids that serve as essential precursors for collagen (the primary structural protein of cartilage, tendons, and ligaments), keratin (the structural protein of skin, coat, and nails), and glutathione.¹ In connective tissue specifically, sulphur is required for the disulphide cross-links that stabilise collagen’s triple-helix structure and for the sulphation of GAGs — including chondroitin sulphate, keratan sulphate, and heparan sulphate — that give cartilage its ability to resist compressive forces.

DiSilvestro and DiSilvestro (2008) demonstrated that five weeks of oral MSM administration in mice produced a statistically significant 78% increase in liver glutathione concentration, providing direct evidence that MSM-derived sulphur is incorporated into the glutathione synthesis pathway.⁹ This is particularly significant because glutathione is the body’s master intracellular antioxidant, and its depletion is directly implicated in both joint inflammation and liver injury.

NF-κB Pathway Inhibition and Multi-Transcription Factor Modulation

MSM is a potent inhibitor of the NF-κB inflammatory signalling pathway — the same master regulatory pathway inhibited by glucosamine and curcumin. Cheleschi et al. (2018) demonstrated in human chondrocyte cultures that MSM prevented the negative effects of IL-1β via NF-κB signalling pathway suppression, reducing the expression of downstream inflammatory mediators.² Kim et al. (2009) similarly showed in murine macrophages that MSM reduced LPS-induced inflammatory responses by inhibiting NF-κB activation, decreasing the production of nitric oxide (NO), prostaglandin E₂ (PGE₂), and the expression of COX-2 and iNOS — two key enzymes that drive joint inflammation and cartilage degradation in osteoarthritis.¹³

The comprehensive review by Butawan et al. (2017) established that MSM’s anti-inflammatory and antioxidant actions extend beyond NF-κB alone, influencing at least four major transcription factors.¹ These are NF-κB (the master inflammatory regulator), STAT (signal transducers and activators of transcription, involved in cytokine signalling), p53 (the tumour suppressor and redox sensor), and Nrf2 (nuclear factor erythroid 2-related factor 2, the master regulator of antioxidant gene expression).¹ Through its effects on these transcription factors, MSM can simultaneously suppress inflammatory cytokine production (via NF-κB and STAT inhibition), enhance antioxidant enzyme expression (via Nrf2 activation), and modulate the cellular redox balance.¹

NLRP3 Inflammasome Suppression

At the subcellular level, MSM negatively affects the expression and activation of the NLRP3 inflammasome — a multiprotein complex that senses cellular stress signals and drives the maturation and release of the pro-inflammatory cytokines IL-1β and IL-18.¹ MSM achieves this through two complementary mechanisms: downregulating NF-κB-dependent transcription of the NLRP3 inflammasome gene, and blocking the activation signal in the form of mitochondrial-generated reactive oxygen species (ROS).¹ This is particularly relevant to osteoarthritis, where NLRP3 inflammasome activation in chondrocytes and synovial macrophages is increasingly recognised as a key driver of chronic joint inflammation.

Inhibition of Osteoclastogenesis

Joung et al. (2016) demonstrated a mechanism of MSM activity directly relevant to skeletal health: MSM inhibits RANKL-induced osteoclastogenesis — the process by which bone-resorbing osteoclast cells are formed — in bone marrow macrophages by suppressing both NF-κB and STAT3 signalling.¹⁰ This finding suggests MSM may help protect against the subchondral bone remodelling that accompanies osteoarthritis, and has broader implications for skeletal integrity in ageing dogs.

Chondrogenic Enhancement

Dalle Carbonare et al. (2021) provided evidence that MSM enhances the chondrogenic commitment of mesenchymal stem cells (MSCs) — the progenitor cells responsible for cartilage repair — while simultaneously promoting pre-osteoblast formation.¹¹ In a zebrafish model, MSM increased the expression of SOX-9, the master transcription factor for chondrogenesis, while reducing the expression of RANK (the osteoclast surface receptor) and the pERK/ERK ratio.¹¹ These findings suggest MSM may actively support the body’s capacity to generate new cartilage tissue, not merely slow its degradation.

Health Benefits for Dogs

Pain Reduction and Improved Physical Function

The most robust clinical evidence for MSM comes from three separate randomised, double-blind, placebo-controlled trials in human subjects with knee osteoarthritis — a condition that shares the same fundamental pathology as canine osteoarthritis.

Kim et al. (2006) enrolled 50 men and women (aged 40–76) with knee osteoarthritis and administered either MSM (3 g twice daily; 6 g/day total) or placebo for 12 weeks.⁴ The MSM group demonstrated statistically significant reductions in WOMAC pain and physical function impairment scores compared to placebo (p < 0.05), along with significant improvements in performing activities of daily living on the SF-36 quality of life measure (p < 0.05).⁴ No serious adverse events were reported.⁴

Debbi et al. (2011) conducted a prospective, randomised, double-blind trial in 49 men and women (aged 45–90) with radiographically confirmed knee osteoarthritis.⁵ Participants received MSM (1.125 g three times daily; 3.375 g/day) or placebo for 12 weeks. The MSM group showed improvements in WOMAC pain and physical function scores compared to placebo. The authors noted that while the improvements were statistically detectable, their clinical significance remained to be confirmed, and they recommended larger-scale trials.⁵

Nakamura et al. (2023) enrolled 88 healthy Japanese participants experiencing mild knee pain in a randomised, double-blind, placebo-controlled trial.⁶ MSM (2 g/day) or placebo was administered for 12 weeks. The MSM group demonstrated significantly improved total scores on the Japanese Knee Osteoarthritis Measure (JKOM) compared to placebo (p = 0.046), with particular improvements in pain-related questions and overall health condition scores (p = 0.032).⁶ The authors suggested that MSM’s direct antioxidant effects in the knee may have contributed to pain relief even in the absence of measurable changes in systemic inflammatory markers.⁶

Cartilage Protection in Osteoarthritis Models

Ezaki et al. (2013) provided direct evidence of chondroprotective effects in a well-established osteoarthritis model.³ STR/Ort mice — an accepted spontaneous osteoarthritis model — received MSM-containing diets at doses equivalent to the recommended human supplement dose (0.06 g/kg body weight/day) and at ten-fold higher (0.6 g/kg BW/day) for 13 weeks.³ MSM decreased degeneration of the cartilage at the joint surface in a dose-dependent manner, with the effect evident at both dose levels.³ Importantly, this study also provided safety data: at 100-fold the recommended dose (6 g/kg BW/day), MSM caused atrophy of several organs — but at the physiologically relevant and ten-fold doses, no such effects were observed, confirming a wide margin between effective and adverse dose levels.³

In a 2024 study, Akpınar et al. compared oral MSM against intra-articular methylprednisolone and hyaluronic acid injections in a rat model of post-traumatic ankle osteoarthritis.¹⁴ Over 8 weeks, oral MSM (0.06 g/kg/day) produced significantly better radiological outcomes than the untreated control group (p < 0.001), with histopathological scoring comparable to the injection-treated groups.¹⁴ The study also confirmed MSM’s ability to increase SOX-9 expression (the chondrogenic transcription factor) — consistent with the findings of Dalle Carbonare et al.¹¹˒¹⁴

Anti-Inflammatory Effects: Immune Cell Modulation

van der Merwe and Bloomer (2016) investigated MSM’s effects on exercise-induced inflammation in a randomised, placebo-controlled trial in physically active men.¹⁵ Twenty-eight days of MSM supplementation (3 g/day) prior to a damaging eccentric exercise protocol significantly reduced LPS-stimulated IL-1β secretion from whole blood, demonstrating that MSM modulates the inflammatory responsiveness of immune cells in vivo.¹⁵ The authors concluded that MSM, acting as an antioxidant, blunted tissue damage and the resulting inflammatory cascade, preventing the exercise-induced leukocyte apoptosis observed in the placebo group.¹⁵

Hepatoprotective Effects and Glutathione Elevation

MSM demonstrates consistent hepatoprotective activity across multiple animal models, establishing relevance to the gut-liver axis. DiSilvestro and DiSilvestro (2008) showed that five weeks of oral MSM in mice increased liver glutathione concentration by 78% and partially protected against carbon tetrachloride-induced liver injury.⁹ Kamel and El Morsy (2013) confirmed and extended these findings: MSM pre-treatment (400 mg/kg) significantly protected against CCl₄-induced liver damage in rats by reducing serum ALT and AST, decreasing hepatic MDA (a marker of lipid peroxidation), suppressing TNF-α and IL-6, increasing SOD and catalase activity, and reducing the Bax/Bcl₂ ratio — indicating protection against apoptotic liver cell death.¹⁶

More recently, Park et al. (2023) demonstrated that MSM ameliorates metabolic-associated fatty liver disease (MAFLD) in mice fed a high-fat diet by restoring autophagy flux via the AMPK/mTOR/ULK1 signalling pathway.¹⁷ MSM enhanced insulin sensitivity and significantly suppressed high-fat-diet-induced hepatic steatosis.¹⁷ These findings collectively position MSM as a compound with genuine hepatoprotective potential mediated through antioxidant, anti-inflammatory, and metabolic pathways.

Metabolic and Anti-Obesity Effects

Sousa-Lima et al. (2016) demonstrated in mice that MSM is effective against obesity-induced metabolic disorders, including hyperglycaemia, hyperinsulinaemia, and insulin resistance — effects mediated through improved metabolic profiles in adipose tissue and liver.¹⁸ This metabolic activity is relevant to canine health because obesity is a significant risk factor for osteoarthritis progression in dogs, and metabolic dysfunction driven by adipose tissue inflammation contributes to systemic inflammatory burden through the gut-metabolic axis.

Evidence in Context

It is important to present the evidence honestly. While the mechanistic data for MSM are compelling and multiple clinical trials show positive outcomes, the evidence base has limitations. A systematic review by Brien et al. (2008) noted methodological issues across MSM studies, including small sample sizes, relatively short treatment durations, and inconsistent dosing regimens.¹⁹ The reviewers concluded that while available data were promising, larger and longer trials were needed to draw definitive conclusions about MSM’s clinical efficacy.¹⁹ Critically, the canine-specific clinical evidence for MSM as a standalone agent is limited; most veterinary studies evaluate MSM as part of multi-ingredient formulations — meaning its contribution is difficult to isolate from other active compounds. However, the translational evidence base (shared OA pathology across mammalian species, conserved NF-κB and Nrf2 signalling pathways, and consistent in vivo results across rodent models) provides a sound rationale for its inclusion in canine joint-support formulations.

MSM and Gut Health

One of the most significant and underappreciated dimensions of MSM is its activity within the gastrointestinal tract — establishing direct relevance to the gut microbiome and the gut-joint axis.

Intestinal Barrier Protection

Jiao et al. (2023) provided compelling evidence that MSM directly protects intestinal barrier function.⁷ Using porcine intestinal epithelial cells (IPEC-J2) — a well-established model for mammalian gut physiology — the researchers demonstrated that MSM significantly increased transepithelial electrical resistance (TEER; a direct measure of barrier integrity) while reducing FITC-dextran flux permeability and lactate dehydrogenase activity in cells challenged with lipopolysaccharide (LPS).⁷ Critically, MSM significantly upregulated both mRNA and protein expression of the tight junction proteins occludin, claudin-1, and ZO-1 (p < 0.05) — the structural molecules that seal the paracellular spaces between intestinal epithelial cells and prevent the translocation of bacterial endotoxins and inflammatory triggers from the gut lumen into the systemic circulation.⁷

The study also identified a potential mechanism: MSM prevented the LPS-induced downregulation of epidermal growth factor receptor (EGFR), suggesting that MSM enhances tight junction function through EGFR-mediated protein synthesis in intestinal epithelial cells.⁷ Simultaneously, MSM significantly inhibited the expression of TNF-α, IL-1, and IL-6 in the challenged cells (p < 0.01).⁷

This finding is directly relevant to the gut-joint connection. A compromised intestinal barrier allows microbial products — particularly LPS — to enter systemic circulation, triggering inflammatory cascades that exacerbate joint inflammation. By maintaining barrier integrity, MSM may help interrupt this gut-to-joint inflammatory pathway at its source.

Gut Microbiome Co-Metabolism

Magnuson et al. (2017) used ³⁵S-labelled MSM to trace the metabolic fate of orally administered MSM in mice, revealing a complex dynamic of co-metabolism between MSM and the gut microbiome.⁸ Critically, the researchers found that the ³⁵S from MSM became associated with methionine and cysteine in tissue proteins — amino acids that mammals cannot synthesise de novo with exogenous sulphur.⁸ Since the incorporation of ³⁵S into these amino acids would require microbial metabolism, the findings demonstrate that gut bacteria actively metabolise MSM-derived sulphur, converting it into sulphur-containing amino acids that the host can then utilise.⁸ The authors explicitly noted that cecal bacteria play an important role in this process.⁸

This establishes MSM as more than a passively absorbed supplement; it is an active substrate for microbial metabolism. The sulphur from MSM enters the metabolic economy of the gut microbiome, where it supports the synthesis of mucins (the glycoproteins that form the protective mucus layer of the gut), sulphur-containing amino acids, and sulphated glycosaminoglycans. This is conceptually analogous to the way glucosamine serves as a microbial substrate — and provides a mechanistic basis for the observation that both compounds have activity beyond their traditionally understood roles.

Sulphur, the Mucosal Barrier, and GAG Synthesis

The gut mucosal barrier is composed primarily of mucins — large glycoproteins secreted by goblet cells. These mucins are heavily sulphated, and sulphur is required for their structural integrity and protective function. MSM, as a highly bioavailable organic sulphur source, provides the substrate needed to maintain this mucosal defence layer. This has implications not only for the gut-joint axis but for multiple gut-organ axes — because a compromised mucosal barrier contributes to systemic endotoxaemia, which can drive inflammation in joints, liver, brain, skin, and other organ systems.

Additionally, the sulphated GAGs that MSM helps to build in cartilage are the same class of molecules that form the glycocalyx — the carbohydrate-rich layer that lines the intestinal epithelium and contributes to barrier function. This dual role of sulphated GAGs in both joint and gut health provides a compelling molecular explanation for why sulphur-containing compounds like MSM and glucosamine have demonstrated activity across both systems.

The Gut-Liver Axis Connection

MSM’s hepatoprotective effects (discussed above) are directly relevant to the gut-liver axis. The liver receives the majority of its blood supply from the portal vein — directly from the gut — and is therefore the first organ exposed to microbial products that breach the intestinal barrier. MSM’s dual activity — protecting the intestinal barrier (reducing the translocation of endotoxins) while simultaneously increasing liver glutathione (enhancing the liver’s capacity to neutralise those endotoxins that do reach it) — represents a coherent, two-pronged defence of the gut-liver axis.⁷˒⁹˒¹⁶

For a comprehensive overview of how gut health influences joint inflammation and mobility in dogs, see our dedicated article: The Gut-Joint Axis in Dogs – Nutritional Impact on Mobility.

Why Bonza Includes MSM

MSM is included across three Bonza products — Bounce Bioactive Bites (120 mg per chewy), Boost Bioactive Bites (90 mg per chewy), and Superfoods & Ancient Grains complete food — because it addresses a fundamental requirement that no other joint-support ingredient fully replaces: providing the bioavailable sulphur from which cartilage, collagen, and glutathione are constructed.

Multi-pathway formulation design. In Bounce, MSM at 120 mg per chewy works alongside glucosamine HCl (240 mg), chondroitin sulphate from Greendroitin (80 mg), hyaluronic acid (5 mg), ASU (10 mg), Boswellia serrata (10 mg), and curcuma longa (10 mg) to create a comprehensive joint-support formulation. Each ingredient addresses a different aspect of osteoarthritis pathology: glucosamine provides the amino sugar substrate for GAG biosynthesis; chondroitin inhibits matrix-degrading enzymes; hyaluronic acid restores synovial fluid lubrication; ASU stimulates chondrocyte collagen production; and boswellia and curcumin provide complementary anti-inflammatory activity through 5-lipoxygenase inhibition and NF-κB modulation respectively. MSM’s unique contribution is twofold — providing the sulphur that makes the GAGs and collagen produced by these other compounds structurally sound, and independently suppressing NF-κB and NLRP3 inflammasome signalling through its own distinct mechanisms.¹˒²

Synergy with glucosamine and chondroitin. The combination of MSM with glucosamine and chondroitin sulphate has a strong rationale supported by their complementary mechanisms. Usha and Naidu (2004) conducted a randomised, double-blind, placebo-controlled trial comparing glucosamine (500 mg three times daily), MSM (500 mg three times daily), their combination, and placebo in 118 patients with mild-to-moderate osteoarthritis.²⁰ The combination group showed greater improvements in pain and swelling compared to either agent alone, suggesting synergistic or at least additive effects.²⁰ This principle of multi-compound synergy underpins Bonza’s formulation philosophy.

Gut health integration. The gut health dimension is equally intentional. Given MSM’s demonstrated ability to protect intestinal barrier integrity and its co-metabolism by the gut microbiome, Bounce includes prebiotic FOS (80 mg) and β-glucans (83 mg Biolex MB40) to support the microbial environment in which MSM is metabolised. This reflects Bonza’s “One Gut. Whole Dog.” philosophy — the recognition that even traditionally categorised “joint-support” ingredients like MSM have genuine gut-organ axis activity.

In Boost, MSM at 90 mg per chewy is part of a broader multi-system support formulation that includes Calsporin (Bacillus velezensis, 75 mg) and Lactobacillus helveticus (5 mg) — direct probiotic support that further reinforces the microbial ecosystem within which MSM operates. Boost also provides taurine (300 mg), L-carnitine (30 mg), and the full B-vitamin complex, addressing the metabolic dimension that MSM’s effects on insulin sensitivity and AMPK activation suggest may be relevant.¹⁷˒¹⁸

In Superfoods & Ancient Grains, MSM provides daily baseline sulphur support as part of a complete food — meaning dogs receiving Bonza’s complete food are already consuming MSM at a maintenance level before any supplement is added.

Safety Profile

MSM has an excellent safety record and holds GRAS (Generally Recognized As Safe) status.¹ Toxicity studies indicate that MSM is one of the least toxic biological compounds, with an LD₅₀ comparable to water.¹

In the Kim et al. (2006) randomised trial (6 g/day for 12 weeks), no major adverse events were reported.⁴ The Debbi et al. (2011) trial (3.375 g/day for 12 weeks) similarly reported only minor adverse effects — predominantly mild gastrointestinal symptoms — with no significant difference in adverse event rates between MSM and placebo groups.⁵ The Nakamura et al. (2023) trial confirmed no safety concerns through comprehensive physical examination, urine analysis, peripheral blood testing, and medical interview.⁶

The Ezaki et al. (2013) animal study provides important dose-response safety data: at the recommended human-equivalent dose and at ten-fold that dose, no adverse effects on body weight, organ weight, or organ histology were observed over 13 weeks.³ Adverse effects (organ atrophy) were only observed at 100-fold the recommended dose — an extreme exposure level unlikely to be encountered in normal supplementation.³

The VCA Animal Hospitals advisory notes that MSM is generally safe for dogs and cats, with onset of effects typically within 1–2 weeks and full benefits potentially requiring up to 8 weeks.²¹ Occasional gastrointestinal side effects (loose stools, mild diarrhoea) may occur when MSM is first introduced, particularly at higher doses. These effects are typically transient and resolve within a few days.²¹

MSM is not known to have significant drug interactions at supplement-level doses. It can be used alongside NSAIDs. As with any supplement, consultation with a veterinarian is advisable before beginning use, particularly in dogs with pre-existing conditions.

How to Give MSM to Your Dog

Dosage Guidelines

MSM dosage for dogs has not been established by formal dose-finding studies specific to canine patients. The following guidelines are based on veterinary practitioner recommendations and allometric scaling from human clinical trial doses.

Dog’s Weight	Suggested Daily MSM Dose	Bonza Bounce Chewies	Bonza Boost Chewies
Up to 10 kg	50–200 mg	½–1 chewy (60–120 mg MSM)	½–1 chewy (45–90 mg MSM)
10–25 kg	200–500 mg	1–2 chewies (120–240 mg MSM)	1–2 chewies (90–180 mg MSM)
25–40 kg	500–1,000 mg	2–4 chewies (240–480 mg MSM)	2–4 chewies (180–360 mg MSM)
Over 40 kg	1,000–2,000 mg	4+ chewies (480+ mg MSM)	4+ chewies (360+ mg MSM)

Note: Bonza Bounce and Boost deliver MSM as part of comprehensive multi-ingredient formulations. The MSM doses listed above represent only the MSM component — total joint-support activity includes contributions from glucosamine, chondroitin, hyaluronic acid, and other active ingredients. Always follow the feeding guide on your specific product and consult your veterinarian for personalised dosing.

Practical Considerations

Onset of action. MSM is not a fast-acting analgesic. As a structural substrate and transcription factor modulator, its benefits accumulate gradually. Most evidence suggests 4–8 weeks of consistent daily use before meaningful improvements in pain and mobility are observed.⁴˒⁵˒⁶˒²¹ For this reason, owners should not discontinue MSM supplementation prematurely if no immediate effect is noticed.

Combination vs. standalone use. The evidence consistently suggests that MSM delivers its best results when used in combination with other joint-support compounds — particularly glucosamine and chondroitin sulphate — rather than as a standalone supplement.²⁰ Bonza’s Bounce and Boost formulations are designed with this principle in mind, providing MSM alongside complementary ingredients that address different aspects of joint pathology.

Side effects. The most commonly reported side effects are mild gastrointestinal symptoms — loose stools or diarrhoea — typically occurring in the first few days of supplementation and resolving without intervention.²¹ Introducing MSM gradually (starting at half the intended dose) minimises this risk.

Storage. MSM is chemically stable and resistant to decomposition at normal temperatures. Store supplements according to the product label — typically in a cool, dry place away from direct sunlight.

Quality considerations. Not all MSM products are equal. The purification process (distillation vs. crystallisation) affects purity and consistency. Bonza sources pharmaceutical-grade MSM to ensure consistent quality and purity in every batch.

Frequently Asked Questions

Related Reading

• Glucosamine HCl for Dogs: Joint Mobility & Gut-Joint Axis Support
• Hyaluronic Acid for Dogs: Joint Mobility Support
• Avocado-Soybean Unsaponifiables (ASU) for Dogs: Joint Protection & Mobility Support
• Boswellia Serrata for Dogs: Positive Health Impacts
• Best Joint Supplement for Dogs: Science-Informed Bioactive Ingredients
• The Gut-Joint Axis: How Your Dog’s Gut Health Affects Their Joints
• The Gut Microbiome: Your Dog’s Hidden Health Command Centre
• Gut-Organ Axes: How They Impact Dog Health
• The Gut-Liver Axis: How Your Dog’s Gut Health Affects Their Liver
• Arthritis in Dogs: A Comprehensive Guide

References

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11. Dalle Carbonare L, Bertacco J, Marchetto G, et al. Methylsulfonylmethane enhances MSC chondrogenic commitment and promotes pre-osteoblasts formation. Stem Cell Research & Therapy. 2021;12(1):326. doi:10.1186/s13287-021-02396-5
12. Rizzo R, Grandolfo M, Godeas C, Jones KW, Vittur F. Calcium, sulfur, and zinc distribution in normal and arthritic articular equine cartilage: a synchrotron radiation-induced X-ray emission (SRIXE) study. Journal of Experimental Zoology. 1995;273(1):82-86. doi:10.1002/jez.1402730111
13. Kim YH, Kim DH, Lim H, Baek DY, Shin HK, Kim JK. The anti-inflammatory effects of methylsulfonylmethane on lipopolysaccharide-induced inflammatory responses in murine macrophages. Biological and Pharmaceutical Bulletin. 2009;32(4):651-656. doi:10.1248/bpb.32.651
14. Akpınar B, Gümüştaş SA, Bülbül AM, et al. The effect of MSM in the treatment of ankle arthrosis: Is MSM as effective as methylprednisolone or hyaluronic acid? Journal of Orthopaedic Research. 2024;42(6):1389-1398. doi:10.1002/jor.25795
15. van der Merwe M, Bloomer RJ. The Influence of Methylsulfonylmethane on Inflammation-Associated Cytokine Release before and following Strenuous Exercise. Journal of Sports Medicine. 2016;2016:7498359. doi:10.1155/2016/7498359
16. Kamel R, El Morsy EM. Hepatoprotective effect of methylsulfonylmethane against carbon tetrachloride-induced acute liver injury in rats. Archives of Pharmacal Research. 2013;36(9):1140-1148. doi:10.1007/s12272-013-0110-x
17. Park SY, Chung MJ, Son JY, et al. Methylsulfonylmethane ameliorates metabolic-associated fatty liver disease by restoring autophagy flux via AMPK/mTOR/ULK1 signaling pathway. Frontiers in Pharmacology. 2023;14:1302227. doi:10.3389/fphar.2023.1302227
18. Sousa-Lima I, Park SY, Chung M, et al. Methylsulfonylmethane (MSM), an organosulfur compound, is effective against obesity-induced metabolic disorders in mice. Metabolism. 2016;65(10):1508-1521. doi:10.1016/j.metabol.2016.07.007
19. Brien S, Prescott P, Bashir N, Lewith H, Lewith G. Systematic review of the nutritional supplements dimethyl sulfoxide (DMSO) and methylsulfonylmethane (MSM) in the treatment of osteoarthritis. Osteoarthritis and Cartilage. 2008;16(11):1277-1288. doi:10.1016/j.joca.2008.03.002
20. Usha PR, Naidu MU. Randomised, double-blind, parallel, placebo-controlled study of oral glucosamine, methylsulfonylmethane, and their combination in osteoarthritis. Clinical Drug Investigation. 2004;24(6):353-363. doi:10.2165/00044011-200424060-00005
21. VCA Animal Hospitals. Methylsulfonylmethane (MSM). VCA Animal Hospitals Know Your Pet. Available at: https://vcahospitals.com/know-your-pet/msm. Accessed February 2026.

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Editorial Information

Field	Detail
Published	February 2026
Last updated	February 2026 — New article; comprehensive evidence review including 2024 ankle arthrosis study (Akpınar et al.) and 2023 MAFLD/AMPK research (Park et al.)
Reviewed by	Glendon Lloyd, Dip. Canine Nutrition (Dist.), Dip. Canine Nutrigenomics (Dist.)
Next review	August 2026
Author	Glendon Lloyd
Disclaimer	This article is for educational purposes only and is not intended to replace professional veterinary advice. Always consult your veterinarian before introducing any new supplement to your dog’s diet.

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About the Author

Glendon Lloyd Dip. Canine Nutrition (Distinction) · Dip. Canine Nutrigenomics (Distinction) Founder, Bonza

Glendon is the founder of Bonza and a qualified canine nutritionist and nutrigenomics specialist. He reads 5–6 peer-reviewed studies weekly to ensure Bonza’s formulations and educational content reflect the latest science. His mission — “Add years to their life, and life to their years” — drives Bonza’s commitment to evidence-based, gut-first canine nutrition.

Read Glendon’s full bio →