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.

The real issue, therefore, becomes one of purity (and stability). Our highly stable D-Glucosamine Hydrochloride is domestically manufactured in an FDA approved, GMP plant and is 99+ percent pure with less than 0.1% ash on ignition. On the other hand, pure Glucosamine Sulfate is very hygroscopic and degrades rapidly (goes from white to off-white to tan to brown) when exposed to moisture. To avoid this problem, Glucosamine sulfate, as currently imported, is made from glucosamine HCl by adding either sodium or potassium sulfate and co-crystallizing the resulting mixture. For this reason, virtually all of the glucosamine sulfate imported into the US is only 80% pure with the remaining 20% being sodium or potassium chloride (this accounts for the high percentage of ash found in the sulfate on ignition). In a dietary supplement market that is under constant government and media scrutiny, purity and stability are key elements for success.

There is also the additional question of economics. Because glucosamine sulfate is made from glucosamine hydrochloride, it is significantly more expensive - approximately 1.5 times the price of the hydrochloride. The presence of 20% by weight sodium (or potassium) chloride in order to avoid stability problems further dilutes the sulfate and significantly adds to the cost of the sulfate on an active glucosamine basis. Conversely, D-Glucosamine HCl provides a high purity, stable source of glucosamine that is readily absorbed by the body and is the most cost effective form of glucosamine available.

The NutraSense Company, in cooperation with Pfanstiehl Laboratories Inc. (the only US manufacturer), offers D-Glucosamine Hydrochloride to the pharmaceutical, health-nutrition, and animal health markets. Pfanstiehl operates an FDA approved, GMP plant that manufactures pharmaceutical grade D-Glucosamine Hydrochloride of the highest quality.

Product Comparsion
GLUCOSAMINE-ES (Glucosamine HCl)		Comparative Attribute	Glucosamine Sulfate (NaCl added)
99+%	«	Purity (as the specific salt)	80%
83.1%	«	Bio-Active Glucosamine (as the free base)	62.8%
1,500 mg	«	Equivalent Dosage (Based on Active)	1,995 mg

• Functionality - Both the hydrochloride and sulfate dissolve (ionize) completely in the stomach's hydrochloric acid which makes all of the glucosamine present, regardless of the source, readily available for absorption in the small intestine. Once absorbed into the blood stream, the glucosamine, independent of the original salt, is equally available to the body.
  

• Purity - GLUCOSAMINE-ES is highly stable and manufactured to a purity of over 99%. On the other hand, the sulfate is only 80% pure as it manufactured by adding 2 moles of sodium (or potassium) sulfate to Glucosamine Hydrochloride and co-crystallizing the mixture. The resulting product is approximately 20% by weight sodium (or potassium) chloride.
  

• Bio-Active Glucosamine - The neutral aminosugar, glucosamine, is the real bio-active material that acts as the precursor to the body's synthesis of glycosaminoglycans, hyaluronate, proteoglycans, and collagen - all the necessary components to repair and maintain healthy cartilage and joint function. Based on the aforementioned purity and the relative molecular weights of glucosamine and each of its salts, simple math shows that GLUCOSAMINE-ES delivers 83.1% active glucosamine while the sulfate supplies only 62.8%.
  

• Equivalent Dosage - The suggested daily dosage is 1,500 mg of GLUCOSAMINE-ES. In order to get the equivalent amount of glucosamine found in 1,500 mg of the hydrochloride, you would need to take 1,995 mg of the sulfate.
  

• Daily & Monthly Usage - If both products are packaged in 750 mg capsules, you would have to take 2.66 sulfate capsules daily compared to only 2 GLUCOSAMINE-ES capsules in order to get the same amount of active glucosamine. On a monthly basis you would need 80 capsules of sulfate to equal 60 capsules of GLUCOSAMINE-ES. If packaged 60 capsules to a bottle, you would need to buy 4 bottles of sulfate for every 3 bottles of GLUCOSAMINE-ES.

Other Information: Glucosamine - A Review of Literature A brief technical summery of past publications which substantiated the effects of Glucosamine HCL