The shelf of horse supplements is enormous, and the packaging promises a lot. Before you buy a tub, it helps to know what a supplement actually does, when there's a genuine gap in the ration it can fill, and when you're mostly paying for the packaging.
What a Supplement Is — and Isn't
A supplement is an addition to the ration: extra vitamins, minerals, or specific compounds you give alongside forage and, where relevant, concentrate feed. It is not a medicine. In the Netherlands, a supplement is not allowed to claim it cures a disease; if a package does so anyway, that's a red flag.
So the first thing that matters isn't which tub you choose, but whether the basics are right. A horse that gets enough good forage, moves enough, and is at a healthy weight often needs little extra. You address a shortfall in a targeted way; "loading up" a well-fed horse with supplements rarely achieves anything, and some vitamins and minerals are actually harmful in excess.
First the Basics: Forage, Balance, and Weight
Before you look at supplements, review the ration. Most shortfalls don't happen because a horse isn't getting a tub of powder, but because the basics aren't in order.
- Enough forage? The rule of thumb is roughly 1.5 to 2% of body weight in forage per day, spread across the day.
- Is it getting the right amount of concentrate feed? Much concentrate feed is already fortified with vitamins and minerals. Feed the amount recommended on the bag and a large part of the requirement is often already covered. Feed much less than that, and a shortfall can actually arise — which is what balancers exist for, among other things.
- Is the weight and condition right? A horse that's too thin or too heavy isn't fixed with a supplement, but by adjusting the ration and exercise.
If you really want to know what's in the base feed, you can have the forage analyzed. That gives a far better picture of any shortfalls than guessing based on an advertisement.
Joint Supplements: Holding the Claims Up to the Light
Joint supplements are one of the largest categories, often based on compounds such as glucosamine, chondroitin, MSM, or green-lipped mussel. The idea behind them is that they support cartilage and reduce stiffness, for example in an older horse or a sport horse under heavy load.
The evidence is mixed. For some compounds there are studies showing a mild effect; for others the evidence is weak or contradictory, and the amount of active ingredient varies widely between products. A supplement is also no substitute for a diagnosis. A horse that moves stiffly or is lame belongs with the vet first — there can be something behind it (arthritis, an injury) that a different, more targeted treatment or an adjusted work schedule fits better.
If you're considering a joint supplement, this is a reasonable approach:
- Discuss it with your vet, especially for a horse that already has symptoms.
- Check whether the active ingredient and the amount appear on the label, not just a brand name.
- Give it a reasonable trial period (usually several weeks to months) and assess whether you actually see a difference.
- Keep in mind that some substances can fall under doping regulations in competition; check this in advance.
Electrolytes: When You Need Them, When You Don't
Electrolytes (salts such as sodium, potassium, and chloride) are lost by a horse through sweat. So the question "does my horse need electrolytes?" mostly depends on how much it sweats.
| Situation | Are electrolytes worthwhile? |
|---|---|
| Recreational horse, light work, moderate weather | Usually not — a salt lick and clean water are often enough |
| Solid training or competition with heavy sweating | Can be worthwhile, around the effort |
| Long exertion or heat (endurance, hot day) | More often worthwhile, tailored in consultation |
| Horse that drinks poorly on the road | A point of attention — discuss with your vet |
A few points that often go wrong. Only give electrolytes to a horse that's also drinking; salt without enough water backfires. Many horses already cover their daily salt requirement with a salt lick or a scoop of table salt, and only need extra during heavy sweating. Common advice is to give electrolytes around the effort rather than a large dose every day as standard. If you're unsure about the amount and timing, coordinate it with your vet, especially if your horse performs a lot in the heat.
The Rest of the Shelf
A few best-selling categories, briefly:
- Biotin (hoof growth). Can help horses with poor, crumbly hooves, but it works slowly: the hoof grows from top to bottom, so expect many months before you see an effect. For a horse with already-healthy hooves it's usually unnecessary.
- Stomach/ulcer support. Gastric ulcers are a serious, common problem, but a nutritional supplement is no substitute for diagnosis and treatment. If you suspect stomach issues, that belongs with the vet; a supplement can be supportive at most.
- Calming supplements (often magnesium or herbs). The effect varies and depends heavily on the cause of the restlessness. Restlessness more often comes from too little exercise, too much concentrate feed, or an unclear approach than from a deficiency. Here too, watch the doping regulations for competition.
- Vitamin and mineral mixes / balancers. Most defensible for horses that get little or no concentrate feed and so miss out on the additions it provides. A balancer then tops this up in a targeted way without adding extra energy.
Evaluating a Product Before You Buy
Whether a supplement is worth it comes partly from the label and partly from your horse's situation. A short checklist:
- Does it state what's in it, and how much? Active ingredients with quantities are a good sign; vague "herbal blends" without figures are not.
- Does the claim match what a supplement is allowed to say? Promises to "cure" something don't belong on a nutritional supplement.
- Is there an actual shortfall or problem? Give it in a targeted way, not just to be safe. More isn't better, and some substances build up harmfully in excess.
- Does it fit with competing? Some ingredients fall under doping or medication regulations. Check this in advance with the KNHS (the Dutch equestrian federation) or the FEI (the international equestrian federation).
- What does it cost per day, and do you see a difference? Convert the price to a daily dose and, after a fair trial period, evaluate whether you really notice the effect.
In Short
- A supplement fills a shortfall; it doesn't repair a ration that isn't right and doesn't replace a diagnosis.
- Start with the basics: enough forage, the right amount of concentrate feed, weight and exercise in order.
- Joint supplements have mixed evidence — discuss them with the vet and judge the effect yourself over a few weeks.
- Electrolytes are mainly worthwhile with heavy sweating and only for a horse that drinks; many horses get by with a salt lick.
- Read the label for active ingredient and amount, give it in a targeted way, and check the doping regulations if you compete.
For the choice of which supplement (or none) fits your horse, your vet or a nutrition specialist remains the best source — this overview helps you prepare for that conversation and read the claims on the packaging with a critical eye.
See also: Veterinary Health Care: Vaccinations, Deworming, and Dental Care · Daily Horse Care: The Basic Routine · Glossary: supplements · Level: Considering Your Own Horse