PSSMFLEX for Horses | Daily Organic Support for Muscle Stiffness, Tying-Up, & Energy Metabolism

When movement restriction is coming from muscle rather than joint, the signs often look a little different.

Your horse feels tight through the body; they take longer than they should to warm up; movement can feel short, restricted, or lacking its usual swing and freedom; and some horses seem to hold themselves almost as though they're bracing against their own muscles.

Over the years I've learned that the owner of a PSSM horse has usually researched the life out of it, so there's often little "advice" we can give. What we can do is recognise the patterns. Many of these horses don't necessarily look lame - in fact, some can look quite capable. They simply seem to be working harder than they should for the movement they're producing.

The issue isn't always obvious discomfort either - sometimes it's that familiar feeling that your horse never quite relaxes into their body.

That's where PSSMFlex fits into the picture.

Rather than focusing on joints or general comfort, PSSMFlex is designed to support the muscle system itself - helping maintain efficient energy use, healthy muscle function, and a more comfortable way of going day to day.

In simple terms? Support the muscle system properly, and the movement begins to flow again.

Is this your horse?

✔ Has a history of PSSM, tying-up, or muscle soreness after work
✔ Feels tight, short, or restricted, particularly when first moving off
✔ Takes a long time to warm up, or never quite feels loose
✔ Shows signs of stiffness through the back, hindquarters, or whole body
✔ Can feel wooden, choppy, or lacking swing
✔ Feels better with consistent work and routine, but worse with rest or change
✔ You're instinctively thinking, "this feels muscular rather than joint-related"

In short: if your horse shows those tight, holding, muscle-based movement patterns, PSSMFlex provides targeted support for muscle function, recovery, and efficient energy use.

From there, support can be layered depending on what you’re seeing.

Supporting the wider movement picture

• JointReflexa – where additional support for connective tissue, joint integrity, and long-term structural soundness is needed alongside muscle support.

• JSTTonic – where stiffness begins to overlap with age-related wear-and-tear patterns.
• DuoBute – for additional daily support where muscles or surrounding tissues feel tight or sore, or less free than usual.
• TriBute – for short-term support during flare-ups, workload changes, travelling, competitions, or more reactive periods.

Together, these create a layered approach that supports movement from multiple angles – muscle function, structural resilience, and day-to-day comfort.

The foundations

Without a solid mineral foundation, even the best muscle support can only go so far. Supporting your horse’s baseline nutrition with a forage-based mineral blend such as VitaComplete or EquiVita helps provide the nutrients that muscles, connective tissues, and recovery pathways depend upon every day.

*If you're not already feeding a mineral balancer, try one of our 1Kg trial bags.

PSSMFlex is a nutritional, functional food supplement and not veterinary medicine. See Dr Kellon's Horse Sense - Nutrition is not 'Alternative' Therapy .

What's in PSSMFlex?

PSSMFlex combines two targeted nutrients with Cramp Bark, chosen to support muscle energy, recovery and relaxation when stiffness, tightness or tying-up patterns are part of the picture.

Ingredients: L Glutamine , Acetyl L-Carnitine and organic Cramp Bark ( Viburnum opulus ).

Feed guide

5g/100kg bodyweight per day, i.e. 25g for a 500kg horse.

• Amino acids manufactured to ISO, BP, USP & EP requirements and/or food grade specifications.
• NB. Each ingredient is available separately - links above.

Functional intent

PSSMFlex is designed to support muscle function, energy metabolism, and tension release in horses prone to stiffness, tightness, or tying-up patterns.

It works across three key areas:

• muscle energy production and utilisation
• muscular relaxation and tension release
• tissue recovery and resilience

Functional categories – muscle support in action

1. Muscle Energy Production & Metabolism - Acetyl L-Carnitine
   - Supporting the efficient use of fatty acids within muscle cells, helping maintain steady energy supply and reduce fatigue or exercise intolerance.
2. Muscle Fibre Relaxation & Tension Release - Viburnum opulus (Cramp Bark)
   - Supporting the natural ability of muscle fibres to contract and release, helping reduce tightness, stiffness, and that “held” feeling through the body.
3. Muscle Repair & Tissue Resilience - L-Glutamine
   - Providing key amino acids required for muscle repair, recovery, and overall tissue integrity following work or metabolic strain.

Big picture

PSSMFlex is designed to support how muscles function - how they fuel, move, and recover.

Used consistently, it helps horses feel looser, more capable, and more comfortable in their bodies, particularly where movement restriction is driven by muscular rather than structural factors.

In simple terms: support the muscle system properly, and the movement begins to flow again.

Advisories