Glucosamine

Glucosamine Hydrochloride vs. Sulfate

There is discussion over which of the two glucosamine salts, hydrochloride or sulfate, is preferred for the treatment of osteoarthritis.

The answer is straightforward - both salts, in the pure form, deliver equally effective amounts of the desired glucosamine to joint cartilage. If there is a preference, it should be based on relative purity and economics.

Historically, the sulfate was used for the initial European clinical studies because it was made available for that purpose by an Italian pharmaceutical company which had a proprietary position on the sulfate. Thus, it was to their marketing advantage to supply only the sulfate and ignore the hydrochloride.

The original researchers, however, clearly relate all of the observed benefits relative to osteoarthritis to "glucosamine" not to the sulfate. When ingested, glucosamine sulfate is fully ionized in the stomach by the relatively strong concentration of hydrochloric acid (pH 1 - 3) naturally present. As a result, glucosamine ions and sulfate ions are thoroughly mixed with an overwhelming number of chloride and hydrogen ions from the hydrochloric acid. If you could stop at this point and recover the glucosamine salt, you would get 99+% glucosamine hydrochloride as the sulfate is essentially lost due to its very low concentration relative to the extremely large amount of hydrochloric acid present.

As reported by Setnikar1, 54% of the glucosamine that moves into the small intestine (pH 6.8) exists in its un-ionized, amine form (not a salt at all) while 46% is ionized (the amine group is protenated and positively charged). In the blood at pH 7.4, 75% of the glucosamine is present as the neutral amine while only 25% is ionized. Since ionization or high polarity is usually an obstacle in the crossing of cellular membranes, the ability of glucosamine to exist predominantly in its less polar, un-ionized form in the small intestine and, even more so, in the blood contributes directly to its bioavailability. The specific salt form is relevant only as a convenient delivery vehicle with the proviso that the salt must readily dissolve (ionize) in stomach acid when ingested - the hydrochloride and the sulfate equally meet this requirement.

Meta analysis

Conclusion

This systematic review and meta-analysis found that chondroitin, glucosamine or a combination of both do not have a useful clinical effect in the treatment of osteoarthritis. The supplements were also not found to be harmful. This study benefited from an extensive search for studies on these supplements, and made good use of all the data available by combining results in the network meta-analysis.

However, as with all meta-analyses, the studies included varied in a number of ways, including the severity of the osteoarthritis studied, the main joint involved, or how long the patients were followed up for. This is called heterogeneity. Using the network meta-analysis, the researchers were able to combine evidence from different comparisons of the supplements. This means that the heterogeneity was more complex to calculate, but the researchers say it was low enough to allow them to combine the trials reliably.

A meta-analysis was needed as the randomised controlled trials involving these supplements were small. While it appears from this study that the effects of these supplements are limited, a small effect in a small group of patients could have had a relatively large effect on the overall results. A large randomised controlled trial on a clinically defined group of patients is the best way to assess the effectiveness of these treatments.

Glucosamine and chondroitin are not currently part of the treatment strategy for osteoarthritis recommended by NICE. Patients should consult their GP about the best pain-management options available to them.

Equine Doseages

While "exact" recommended dosages of many ingredients are not available, the following ingredient doses can be used as general guidelines for an average 1,100-pound horse, based on the results of scientific studies:

• Glucosamine: Approximately 12 g of glucosamine hydrochloride (HCl) or 15 g of glucosamine sulfate per day (this is equivalent to approximately 10 g of glucosamine "free base" per horse per day, or the part that gets absorbed systemically).
• Chondroitin sulfate: 2.4 g per horse per day.
• ASU: 2,100 mg per horse per day in combination with glucosamine and chondroitin sulfate.
• MSM: Up to 10 g per horse per day. Other things to look for: