Glucosamine Sulphate Vs Glucosamine HCl… and why you need to check the labels!

glucosamine sulphate, glucosamine for horses, joint supplement for horses

Glucosamine is probably the most important ingredient of any joint supplement. It is found naturally in cartilage, and has an important role to play in cushioning the joints. As the body ages, wear and tear to the joints increases to the point where the body can no longer make enough glucosamine of its own to prevent damage. This is when a supplement comes in – providing glucosamine in the diet ensures a readily available supply for maintaining healthy joints despite increased age or workload.

In most equine supplements, the glucosamine has been extracted from the shells of crustaceans. There is also a man-made vegetarian source, but this is not common place. Glucosamine does not exist as a pure glucosamine molecule – a bit like sodium,  You can’t feed pure sodium, it is only ever in the form of sodium chloride (common salt). With glucosamine, there are two common forms – glucosamine hydrochloride (glucosamine HCl) & glucosamine sulphate. (there is a third that you may come across – N-acetyl glucosamine but it works slightly differently in the body) 

So, is there a difference?

The key difference between these two forms of glucosamine is purity. They cannot be compared like for like –

Glucosamine HCl contains about 99% glucosamine

Glucosamine Sulphate has to be stabilised with a salt (usually potassium chloride) and only contains about 74% actual glucosamine.

So, if your supplement contains ‘10,000mg of glucosamine’

If the source is glucosamine HCl, you are getting 9900mg pure glucosamine, 


If the source is glucosamine sulphate your horse is only getting 7400mg of glucosamine, which is as big difference. You have to feed 35% more of the supplement to get the same specification!

Check your labels!

If in doubt, check your labels! By feed law, the manufacturer has to declare which source of glucosamine is being used in their product. But only last week, we found a joint supplement for horses being marketed as a premium product (at a premium price) and claiming to have one of the highest specifications of glucosamine on the market. They claim that this product provides 15000mg of glucosamine per 50g dose, BUT, when you look at the label it declares 298g glucosamine SULPHATE per kilo. 298g/kilo does work out as virtually 15,000mg per day, but as they use glucosamine sulphate your horse is actually only getting 11,100 mg per day!…