Glucosamine sulfate: this is a synthetic salt that is better absorbed. Much better than the chloride form and the natural versions. My parents have been on it for over 15 years, 1gr per day. Same for my husband who was a runner on city concrete for 40 years. Recently he had a problem with his knee and he was sure a knee replacement is in his future. The orthopedist told him he has the knees of a 20 year old and sent him to an orthopedist who deals with athletic injuries. I can't say for sure it was the glucosamine but I think it helped. Both my parents are also doing well on it. They're almost 90. I'm starting to take it. I have a knee injury from a car accident from years ago that is starting to bother me. I'm hoping it will help. I probably should have started taking it before.
5-loxin: 75 mg. This is a standardized boswellia extract. My dad had severe arthritis in his hands, swollen red joints and twisted fingers. My dad and my husband both took 5-loxin with the glucosamine for years. It inhibits the metalloproteases that degrade the cartilage. My dad's hands healed fairly quickly but his fingers stayed twisted. The pain was gone and he hasn't had to do anything for them except for the glucosamine and 5 -loxin. He also takes a fish oil supplement. He doesn't miss a day. Again this is one person's experience.
I added boron and silica to their supplements and I also started taking them about a year ago. There is enough evidence that both are important for bone and joint health. I noticed that I stopped losing my hair and my nails got much stronger. They used to be so thin, they would bend backward frequently. Not anymore. I can't say it's the boron or silica since I take other supplements, mostly mitochondrial support, vitamin D, Ca, Mg, and a low dose multivitamin that gives me about 50% of the RDA per day.
The boron dose I'm taking is 2x 3 mg. There are population studies that correlate intake of ~13 mg with healthy bones and joints (absence of arthritis). However, correlation is not causation but it felt safe/useful to add some boron.
I take the Now brand bamboo silica because it is purified to remove toxic compounds. I take 325 mg a day. I'll continue with it probably for life. Intake from food in the US is fairly low, 30 to 60 mg per day, much higher in some other countries. The FDA recommends not to exceed 10 to 30 grams per day. My diet is high in silica rich food like lentils, oats, bananas, green beans, bamboo shoots.... I probably get between 50 and 100 mg per day. I can't see ever getting even 1 gram from food. Boron and silica are 2 minerals that I would like to see more studies on. It'll probably never happen despite the fact that so many of us are dealing with arthritis and osteoporosis.