Both glucosamine and chondroitin sulfate do not provide relief for patients with symptomatic osteoarthritis of the knee.
Sources:
American Academy of Orthopaedic Surgeons. Treatment of osteoarthritis of the knee (non-arthroplasty): Full guideline [Internet]. 2008 Dec [cited 2014 Feb 20].
Altman RD, et al. Effects of a ginger extract on knee pain in patients with osteoarthritis. Arthritis Rheum. 2001 Nov;44(11):2531-8. PMID: 11710709.
Bourgeois P, et al. Efficacy and tolerability of chondroitin sulfate 1200 mg/day vs chondroitin sulfate 3 x 400 mg/day vs placebo. Osteoarthritis Cartilage. 1998 May;6 Suppl A:25-30. PMID: 9743816.
Bucsi L, et al. Efficacy and tolerability of oral chondroitin sulfate as a symptomatic slow-acting drug for osteoarthritis (SYSADOA) in the treatment of knee osteoarthritis. Osteoarthritis Cartilage. 1998 May;6 Suppl A:31-6. PMID: 9743817.
Cibere J, et al. Randomized, double-blind, placebo-controlled glucosamine discontinuation trial in knee osteoarthritis. Arthritis Rheum. 2004 Oct 15;51(5):738-45. PMID: 15478160.
Clegg DO, et al. Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. N Engl J Med. 2006 Feb 23;354(8):795-808. PMID: 16495392.
Das A Jr, et al. Efficacy of a combination of FCHG49 glucosamine hydrochloride, TRH122 low molecular weight sodium chondroitin sulfate and manganese ascorbate in the management of knee osteoarthritis. Osteoarthritis Cartilage. 2000 Sep;8(5):343-50. PMID: 10966840.
Giordano N, et al. The efficacy and tolerability of glucosamine sulfate in the treatment of knee osteoarthritis: A randomized, double-blind, placebo-controlled trial. Curr Ther Res Clin Exper. 2009 Jun;70(3):185-96. PMID: 24683229.
Houpt JB, et al. Effect of glucosamine hydrochloride in the treatment of pain of osteoarthritis of the knee. J Rheumatol. 1999 Nov;26(11):2423-30. PMID: 10555905.
Hughes R, et al. A randomized, double-blind, placebo-controlled trial of glucosamine sulphate as an analgesic in osteoarthritis of the knee. Rheumatology (Oxford). 2002 Mar;41(3):279-84. PMID: 11934964.
Kahan A, et al. Long-term effects of chondroitins 4 and 6 sulfate on knee osteoarthritis: The study on osteoarthritis progression prevention, a two-year, randomized, double-blind, placebo-controlled trial. Arthritis Rheum. 2009 Feb;60(2):524-33. PMID: 19180484.
Mazieres B, et al. Chondroitin sulfate in osteoarthritis of the knee: A prospective, double blind, placebo controlled multicenter clinical study. J Rheumatol. 2001 Jan;28(1):173-81. PMID: 11196521.
Mazieres B, et al. Effect of chondroitin sulphate in symptomatic knee osteoarthritis: A multicentre, randomised, double-blind, placebo-controlled study. Ann Rheum Dis. 2007 May;66(5):639-45. PMID: 17204566.
McAlindon T, et al. Effectiveness of glucosamine for symptoms of knee osteoarthritis: Results from an internet-based randomized double-blind controlled trial. Am J Med. 2004 Nov 1;117(9):643-9. PMID: 15501201.
Moller I, et al. Effectiveness of chondroitin sulphate in patients with concomitant knee osteoarthritis and psoriasis: A randomized, double-blind, placebo-controlled study. Osteoarthritis Cartilage. 2010 Jun;18 Suppl 1:S32-40. PMID: 20399899.
Noack W, et al. Glucosamine sulfate in osteoarthritis of the knee. Osteoarthritis Cartilage. 1994 Mar;2(1):51-9. PMID: 11548224.
Pavelka K Jr, et al. Glycosaminoglycan polysulfuric acid (GAGPS) in osteoarthritis of the knee. Osteoarthritis Cartilage. 1995 Mar;3(1):15-23. PMID: 7536623.
Pavelka K, et al. Efficacy and safety of piascledine 300 versus chondroitin sulfate in a 6 months treatment plus 2 months observation in patients with osteoarthritis of the knee. Clin Rheumatol. 2010 Jun;29(6):659-70. PMID: 20179981.
Rai J, et al. Efficacy of chondroitin sulfate and glucosamine sulfate in the progression of symptomatic knee osteoarthritis: A randomized, placebo-controlled, double blind study [Internet]. 2004 January [cited 2014 Feb 20].
Richmond J, et al. Treatment of osteoarthritis of the knee (nonarthroplasty). J Am Acad Orthop Surg. 2009 Sep;17(9):591-600. PMID: 19726743.
Rindone JP, et al. Randomized, controlled trial of glucosamine for treating osteoarthritis of the knee. West J Med. 2000 Feb;172(2):91-4. PMID: 10693368.
Samson DJ, et al. Treatment of primary and secondary osteoarthritis of the knee. 2007 Sep 1. Report No.: 157. PMID: 18088162.
Tao QW, et al. Clinical efficacy and safety of gubitong recipe () in treating osteoarthritis of knee joint. Chin J Integr Med. 2009 Dec;15(6):458-61. PMID: 20082253.
Trc T, et al. Efficacy and tolerance of enzymatic hydrolysed collagen (EHC) vs. glucosamine sulphate (GS) in the treatment of knee osteoarthritis (KOA). Int Orthop. 2011 Mar;35(3):341-8. PMID: 20401752.
Uebelhart D, et al. Intermittent treatment of knee osteoarthritis with oral chondroitin sulfate: A one-year, randomized, double-blind, multicenter study versus placebo. Osteoarthritis Cartilage. 2004 Apr;12(4):269-76. PMID: 15023378.
Zakeri Z, et al. Evaluating the effects of ginger extract on knee pain, stiffness and difficulty in patients with knee osteoarthritis [Internet]. 2011 Aug 4 [cited 2014 Feb 20].