Some are more effective than others. Individual results may vary as people respond differently to the various compounds. If planning on an api cycle, I would get a combo supplement that has Glucos/Chond/MSM in the same bottle. There are many products. I would also start taking it atleast a couple of weeks before the cycle, to allow the supplement time to start working. Along with some Omega-3 fish oil and Olive oil and you should be good to go. A lot of people rave about Cissus but I have never personally tried it.
Glucosamine Sulfate
Chondroitin Sulfate
Methylsulfonylmethane (MSM)
Omega-3 Fish Oil
Cissus
Turmeric extract
Bromelain
Plenty of healthy fats/oils