Glucosamine HCl (Hydrochloride) vs. Glucosamine Sulfate 2KCl
Among 516 on-market glucosamine products with an identifiable primary form, 73.3% use Glucosamine HCl (Hydrochloride) (378 products) and 26.7% use Glucosamine Sulfate 2KCl (138).
| Glucosamine HCl (Hydrochloride) | Glucosamine Sulfate 2KCl | |
|---|---|---|
| Quality tier | Tier 2 | Tier 2 |
| Glucosamine by weight | — | — |
| Share of market | 73.3% | 26.7% |
| On-market products | 378 | 138 |
| Median declared dose | 1,500 mg middle half: 750–1,500 | 750 mg middle half: 500–1,500 |
| Most common brands | Puritan's Pride, Wonder Laboratories, Schiff | Wonder Laboratories, DC, The Vitamin Shoppe |
Doses are declared per serving in mg. “By weight” is the share of the ingredient that is the nutrient itself (e.g. elemental magnesium in a magnesium salt).
Why Glucosamine HCl (Hydrochloride) is tier 2
The largest single trial (GAIT, NIH-funded, n>1,500) used glucosamine HCl and found NO significant overall benefit vs placebo -- weaker/more mixed evidence than sulfate for whole-population efficacy, though one Chinese multi-center RCT found HCl and sulfate equally effective head-to-head; the gap is debated, not settled.
Source: Clegg DO et al. 2006, NEJM 354(8):795-808 (GAIT); Qiu GX et al. 2005, Zhonghua Yi Xue Za Zhi 85(43):3067-3070
Why Glucosamine Sulfate 2KCl is tier 2
A stabilized glucosamine sulfate salt (plain glucosamine sulfate is hygroscopic and needs a stabilizing counter-ion -- historically NaCl in the "Rotta" preparation used in the positive European trials; 2KCl is a common commercial alternative). Evidence for sulfate broadly may reasonably extend here, but no dedicated head-to-head RCT of the 2KCl salt specifically was found -- equivalence is an assumption, not a demonstrated fact.
Source: uncertain -- needs review