This is Why We Don't Combine DMSO with Ozonated Glycerin

If you've spent any time in the equine ozone therapy world, you've probably seen it: ozonated glycerin products that also contain DMSO (dimethyl sulfoxide). It's an easy sell. DMSO has a decades-long reputation as a "carrier" — a solvent that helps other compounds move through skin and tissue faster and deeper. Ozonated glycerin is prized for its antimicrobial, anti-inflammatory, and regenerative activity. Put the two together, the thinking goes, and you get a product that delivers ozone's benefits AND gets there faster.

Two amazing products combined together make something absolutely wonderful! But does it? When we began the process of ozonating glycerin, it was in my mind to create this exceptional duo. This blog traces the process of discovery and will help you understand the reason that we did't end up creating this product.

This isn't an argument that combining DMSO with ozonated glycerin is dangerous. We don't have the controlled data to make that claim, and we're not going to overstate what we know. What we do have is a real chemical reason to ask hard questions, a complete absence of published research on the combination, and a handful of concerning anecdotal reports from horse owners. Taken together, that's enough to justify caution, and enough that we think it deserves a second look before anyone accepts the "better together" story at face value.

What Ozonated Glycerin Actually Is

Ozonated glycerin (OG) starts as a simple, food- and pharmaceutical-grade carbohydrate: glycerin, also called glycerol. On its own, glycerin is about as unremarkable as compounds get: clear, odorless, non-toxic, and so stable it's used as a preservative to keep other things from breaking down.

Bubble ozone gas through it, though, and the chemistry changes substantially. Ozone attacks the hydroxyl (-OH) groups on the glycerin molecule, and new oxygen-containing species form: peroxides, hydroperoxides, and ozonide-like compounds. One proposed active structure is a trioxepane derivative with an endoperoxide scaffold. Unlike ozonated oils, which tend to form more chemically stable cyclic ozonides, ozonated glycerin mostly generates peroxides and hydroperoxides, a difference that matters because it's exactly why storage conditions are such a big deal for this product category. The end result is meant to function as a slow-release reservoir of reactive oxygen species (ROS), and that reservoir is the entire therapeutic point of the product.

A few things follow from that:

  • The active ingredients are inherently unstable. That's not a flaw, it's the mechanism. But it does mean ozonated glycerin is a formulation where "what else is in the bottle" matters a great deal.

  • Ozonated glycerin is also notably acidic with a pH around 2, acidic enough that it needs to be accounted for in dosing and administration route and buffered in some clinical protocols.

  • Shelf life is already a live question even without anything else added. Published peroxide-stability data shows meaningful drop-off in oxidant concentration within the first one to two months for plain, non-stabilized formulations, and practitioner reports vary widely, anywhere from a couple of months to a couple of years, depending heavily on formulation, packaging, and storage. In other words, this is a product class where potency is already fragile and formulation dependent, before you introduce a second reactive ingredient into the mix.

“That fragility is the backdrop for the DMSO question. You're not adding a solvent to an inert base. You're adding it to a solution whose entire value proposition depends on unstable oxidized compounds staying intact.”

What DMSO Actually Is

DMSO earned its reputation honestly. It's an exceptionally effective solvent: it dissolves an unusually wide range of polar and nonpolar compounds, penetrates skin and biological membranes readily, and has been used for decades in both human and veterinary medicine as an anti-inflammatory and as a delivery vehicle for other drugs. None of that is in dispute.

What sometimes gets left out of the marketing conversation is that DMSO is also, chemically speaking, a reactive molecule with a well-documented history of dangerous behavior under the right (or wrong) conditions. DMSO is not a passive, inert carrier that quietly shuttles other molecules around without doing anything of its own. Its safety data sheets flag it as capable of violent, exothermic reactions with oxidizing agents, and industrial and laboratory safety literature has been warning about DMSO's reactivity for decades. Reviews cataloguing DMSO-related incidents point to a string of industrial explosions and injuries going back to the 1960s, tied to DMSO's interactions with acids, bases, oxidants, and reductants. A 1985 incident at a waste treatment plant that was distilling DMSO alongside another reactive compound resulted in an injury and a death. 

“It is capable of violent, exothermic reactions with oxidizing agents, and safety literature has been warning about DMSO's reactivity for decades.”

 

Chemists studying DMSO's decomposition pathways have specifically flagged its behavior in the presence of peroxides. In one published study, researchers found that DMSO actively promotes and accelerates
the breakdown of peroxide-containing compounds, lowering the temperature at which those peroxides start decomposing exothermically. Separately, researchers investigating the industrial production of dimethyl sulfone, the oxidized form of DMSO, have documented that DMSO's reaction with hydrogen peroxide is exothermic enough to require careful thermal management, with clearly defined stages of heat release that have to be controlled to avoid a runaway reaction.

None of this means DMSO is unsafe to use, full stop. It has a long, legitimate track record in the right applications and concentrations. But it does mean DMSO has genuine chemical opinions about being
mixed with oxidizers and peroxide-containing compounds. It is not a neutral bystander.

Where the Concern Comes From

Put those two facts side by side:

  1. Ozonated glycerin's therapeutic value depends on peroxides, hydroperoxides, and ozonide-like compounds remaining intact.
  2. DMSO has a documented chemical relationship with exactly those classes of compounds, one that, in other contexts, has been shown to accelerate their breakdown and, under some conditions, release heat while doing it.

That's the entire concern, and it's a legitimate one to raise. It doesn't require assuming bad intent from anyone selling a combined product, and it doesn't require declaring the combination dangerous. It just requires acknowledging that pairing a peroxide-reliant therapeutic with a solvent known to react with peroxides is a chemistry question that deserves an answer, not an assumption.

There are two separate things worth asking about, and they're not the same question:

Does DMSO degrade the ozonated glycerin's potency?

If DMSO interacts with the peroxide and hydroperoxide content the way it interacts with other peroxide-containing compounds, a product marketed as "more bioavailable ozone" could, in practice, be delivering meaningfully less active oxidative content than an equivalent dose of plain ozonated glycerin, with no easy way for the end user to know how much was lost between mixing and administration.

Could the combination be unstable in storage or preparation?

The exothermic reactions documented in the literature generally involve concentrated reagents, elevated temperatures, or specific catalytic conditions, not necessarily anything close to what happens when these
two liquids are combined at the concentrations used in a topical or injectable product. We want to be precise about that: we are not aware of any published data showing that a horse-side DMSO/ozonated-glycerin product has undergone a hazardous reaction, and we're not claiming one has. What we're pointing out is that the theoretical mechanism for instability exists, and as far as we could find, nobody has published testing that rules it out for this specific combination and use case.

 The Evidence Gap

This is really the core of the issue: as far as we could find, there is no published research (no stability study, no potency assay, no controlled safety data) examining what happens when DMSO and ozonated glycerin are combined.

That's a notable gap, because the underlying ozonated glycerin research base isn't thin. There's a growing body of published work on ozonated glycerin by itself: peroxide and total oxidant value quantification, bactericidal effect studies, antibiofilm and anti-inflammatory research, and stability/shelf-life work looking at how formulation and storage affect oxidant retention over time. Ozonated glycerin, on its own, has real research behind it.

DMSO, separately, also has decades of its own literature: on its anti-inflammatory effects, its use as a drug carrier, and, as covered above, on its reactivity with oxidizers.

 What doesn't exist is research where the two were tested together. Not potency retention over time in a combined formulation, not a comparison of oxidant levels with and without DMSO present, not a controlled safety study of the combined product in any species. The combination is being sold on the logic of two individually well-studied ingredients, without anyone having apparently studied what happens when you put them in the same bottle.

“The combination of ozonated glycerin and DMSO is being sold on the logic of two individually well-studied ingredients, without anyone having apparently studied what happens when you put them in the same bottle.”

That's an important distinction to sit with: "this ingredient has been used safely for a long time" is a true statement about DMSO on its own. It is not the same statement as "this specific combination has been tested and shown to be safe and effective." A product can rest entirely on the first claim while quietly implying the second.

To be fair, I do know that anecdotally some who sell or use this product have tested it on themselves and their own horses, but that’s as far as the research goes.

Reports From Horse Owners

We want to be careful and precise here, because this is the part of the conversation most likely to be misread. 

We're aware of anecdotal reports from horse owners describing neurological events following intravenous administration of an ozonated glycerin product containing DMSO. We want to be upfront about exactly what that is and isn't. These are not documented in peer-reviewed literature. They aren't the result of a controlled study, and in most cases we don't have full clinical documentation: bloodwork, imaging, a ruled-out differential diagnosis list, or confirmation that nothing else was administered around the same time. That means we cannot say, and we're not saying, that these events were caused by the DMSO/ozonated-glycerin combination. Correlation in a handful of unverified, owner-reported cases is not evidence of causation.

What we can say is that these reports exist, that they describe a serious and specific category of adverse event, and that they're occurring in a context where, as laid out above, there is no published safety data on the combination being administered, and where the underlying chemistry gives a plausible (if unproven) mechanism by which something could go wrong. On their own, a few anecdotes wouldn't be much to build an argument on. Alongside a genuine evidence gap and a real chemical question mark, they're a reason to take the question seriously rather than dismiss it.

If you've observed something similar, a neurological event, or any other concerning reaction, following administration of a DMSO-containing ozonated glycerin product, the most useful thing you can do is document it thoroughly (timing, dose, route, symptoms, any other treatments given concurrently) and report it to your treating veterinarian. Detailed, veterinarian-documented case reports are exactly what turns "anecdote" into something the field can actually evaluate.

"But one of my friends uses it" isn't a good argument

One argument you'll hear in defense of combined DMSO/ozonated-glycerin products is that people have been using them for a while without an obvious wave of documented disasters. It's worth taking that
argument seriously and also being precise about what it does and doesn't establish.

Without structured reporting, absence of documented harm mostly tells you that nothing severe enough, common enough, or clearly-enough-linked to the product has surfaced through informal word of
mouth. It doesn't tell you that a controlled study looked for a problem and didn't find one. Those are very different statements, and the gap between them is exactly where anecdotal reports like the ones described above tend to live: real enough to notice, but without the infrastructure in place to systematically capture, investigate, or connect them.

This is also why we think the burden of proof question matters more than it might first appear. It would be a mistake to treat "nobody has proven this combination causes harm" as equivalent to "this combination has been shown to be safe."

Neither of those statements is currently true. What's true is that we don't know, and a plausible chemical mechanism for a problem plus zero controlled testing is a reasonable place to land on "we don't know yet, so let's be careful" rather than "it's fine because nothing's blown up."

“None of this is a mystery, and it doesn't require assuming anyone acted in bad faith. DMSO genuinely has a long track record as an anti-inflammatory and as a delivery vehicle for other compounds. Ozonated glycerin genuinely has real, published therapeutic activity.”

Why the Combination Shows Up in the Market Anyway

None of this is a mystery, and it doesn't require assuming anyone acted in bad faith. DMSO genuinely has a long track record as an anti-inflammatory and as a delivery vehicle for other compounds. Ozonated glycerin genuinely has real, published therapeutic activity. The logic chain, DMSO helps things get where they're going, ozonated glycerin is a good thing to get there, is intuitive, and it's the kind of reasoning that has driven a lot of legitimate advances in topical and injectable formulation over the years.

The problem is that the logic quietly assumes DMSO behaves as a neutral, inert transport mechanism in this specific context, and that assumption is doing a lot of work that hasn't actually been tested. DMSO isn't inert anywhere else in its chemistry. There's no obvious reason to assume it becomes inert specifically when placed next to peroxides and hydroperoxides, given that peroxide reactivity is one of the better documented parts of its chemical profile.

What This Means for Horse Owners and Practitioners

We're not asking anyone to panic, and we're not telling you a specific product is dangerous. We're asking for the same standard of evidence that any other veterinary product would reasonably be expected to meet before widespread adoption: has this specific combination, not each ingredient separately, actually been tested for stability, potency retention, and safety?

A few practical questions worth asking before using or recommending a DMSO-containing ozonated glycerin product:

  1. Has potency been measured in the combined formulation, not just the ozonated glycerin alone? A peroxide/total oxidant value test on the final product, after DMSO has been added, would answer whether the active compounds are surviving the combination.
  2. What does the manufacturer's stability data look like for the combined product specifically, as opposed to general statements about DMSO's safety or ozonated glycerin's benefits individually?
  3. Is there a route or use case where the risk/benefit tradeoff looks different? A theoretical stability or reactivity concern carries different weight for a diluted topical application than it does for an undiluted product administered directly into the bloodstream.
  4. If adopting one of these products, is there a way to monitor for early signs of an adverse reaction, and a plan in place with your vet for what to do if one occurs?

Until there's published data answering the potency and stability questions, we think it's reasonable to treat DMSO-containing and DMSO-free ozonated glycerin products as different things, not identical products where one just happens to work a little faster.

The Bottom Line

We're not claiming that combining DMSO with ozonated glycerin is proven to be dangerous. We're pointing out three things that are true at the same time: DMSO has a documented chemical relationship with
peroxides and oxidizing agents that isn't a neutral one; nobody appears to have published research testing what actually happens when it's combined with ozonated glycerin specifically; and there are unverified but concerning reports from horse owners describing serious adverse events after IV use of a product combining the two.

Individually, none of those three things would be a strong argument. Together, they're a reasonable basis for caution, and a reasonable basis for asking manufacturers, before you use their product, to show the data rather than the logic. Until that data exists, treating DMSO and ozonated glycerin as two separate products, rather than one, seems like the more defensible position for anyone whose job is to do right by the horse in front of them.

*This article reflects an evaluation of publicly available chemical and pharmacological literature and is intended for general informational purposes. It is not a substitute for guidance from a licensed veterinarian. If you have questions about a specific product or treatment plan for your horse, consult your veterinarian.*

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