If you’ve shopped around for joint supplements before, you’ve probably seen that they all contain glucosamine. And there’s good reason for that – it is a well-researched, effective ingredient for providing joint support. But what actually is it, and why does it work so well?
What is it?
Glucosamine is an amino sugar naturally found in the body, where it plays a key role in building glycosaminoglycans (GAGS) - long chain molecules that form an essential part of joint structures. These GAGS are responsible for:
- Shock absorption
- Joint lubrication
- Load distribution within cartilage
There are 3 types of glucosamine available:
- Glucosamine sulphate
- Glucosamine hydrochloride (HCl)
- Injectable glucosamine (usually administered under veterinary supervision)
Of the oral forms, glucosamine HCl has a much higher purity and concentration than sulphate, making small amounts far more effective than its counterpart.
What does glucosamine do?
The body uses amino sugars such as glucosamine to synthesize new GAGS in structures such as ligaments, tendons and cartilage. You’ve probably heard of some of the GAGS that are present in joints, such as chondroitin sulphate and hyaluronic acid.
GAGS in the joints function by attaching to a highly negatively charged protein, that attracts and holds large amounts of water. When weight is put on a joint, water is squeezed out to absorb the impact, and when the pressure is released, the water is pulled back.
They also form synovial fluid, the thick lubricant that minimises friction between bones during movement.
Should it be fed alongside chondroitin sulphate?
Most of the research to date suggests that glucosamine is most effective when fed alongside chondroitin sulphate, as they work synergistically together to reduce inflammatory mediators in the joint and improve repair rate. This is why many high-quality joint supplements include both ingredients.
What does the research say?
Glucosamine is one of the most extensively studied joint supplements across multiple species, including horses, dogs, cats, and humans.
For example, Yamada et al. (2022) found that a combination of glucosamine and chondroitin helped reduce cartilage damage and inflammation in osteoarthritic models.
In healthy joints, there is a natural balance between cartilage breakdown and repair. However, in osteoarthritis, breakdown begins to outpace repair, leading to progressive deterioration, stiffness, and reduced mobility.
This study suggested that supplementation may help support proteoglycan synthesis and cartilage maintenance, potentially helping to slow this imbalance.
That said, not all studies agree. While many show positive or supportive trends, others are mixed or inconclusive. Because of this, glucosamine should be viewed as a supportive aid rather than a cure – and always used alongside appropriate management and veterinary guidance.
Beneficial levels of glucosamine have been cited between 10-20g per daily serving an a 500kg horse (higher levels being more effective for horses under increased joint stress).
Could my horse benefit from glucosamine?
All horses can benefit from being supplemented with glucosamine, but some need it more than others.
Glucosamine is most commonly used for:
- Horses showing stiffness or early joint changes
- Older horses
- Horses in regular or intense work
Take Away
Glucosamine has earned its place as a core ingredient in equine joint supplements because it plays a fundamental role in joint structure and maintenance.
While research shows mixed outcomes in real-world performance, there is consistent evidence that it supports the biological processes involved in cartilage and joint health - especially when combined with ingredients like chondroitin sulphate.
Ultimately, glucosamine should be viewed as part of a bigger picture: supporting joint health through a combination of good nutrition, appropriate exercise, weight management, and veterinary care where needed.
In short: it’s not a miracle ingredient - but it is a useful building block in long-term joint support strategies.
References
Harbowy, R. M., Robison, C. I., Boger, B. L., Manfredi, J. M., & Nielsen, B. D. (2025). Efficacy of an oral chondroprotective joint supplement on stride length and lameness in aged geldings with osteoarthritis. Journal of Equine Veterinary Science, 148, 105453. https://doi.org/10.1016/j.jevs.2025.105453
Moreira, J. J., Coelho, J. M., Machado, T. S. L., Morais, A. P. L., Michelacci, Y. M., & Baccarin, R. Y. A. (2019). Oral glucosamine and chondroitin sulfate on synovial fluid biomarkers from osteoarthritic equine joints. Ciência Rural, 49(9). https://doi.org/10.1590/0103-8478cr20180247
Yamada, A. L. M., do Prado Vendruscolo, C., Marsiglia, M. F., Sotelo, E. D. P., Agreste, F. R., Seidel, S. R. T., Fülber, J., Baccarin, R. Y. A., & da Silva, L. C. L. C. (2022). Effects of oral treatment with chondroitin sulfate and glucosamine in an experimental model of metacarpophalangeal osteoarthritis in horses. BMC Veterinary Research, 18(1). https://doi.org/10.1186/s12917-022-03323-3
Written by Anna Jones BSc (Hons) Equine Science - Customer Care & Marketing Associate