Carpal tunnel syndrome is caused by compression of the median nerve in the wrist. It’s not a joint problem and there’s no valid evidence that joint supplements such as glucosamine are beneficial.
Weight loss (if you’re overweight) and occupational therapy (splinting, exercise, stretching) can help.
And like Rip, I am a board-certified internet physician, licensed to diagnose and treat patients via bulletin board. Although my specialty is breast examinations, I occasionally dabble in surgery of the hand and wrist.