Glucosamine

Glucosamine is a natural substance. Glucosamine is a natural compound found in cartilage — the tough tissue that cushions joints. In supplement form, glucosamine is harvested from shells of shellfish or made in a lab. There are several forms of glucosamine, including glucosamine sulfate, glucosamine hydrochloride and N-acetyl glucosamine. It is marketed with chondroitin sulfate as a treatment for arthritis. Studies indicate that for about 50% of people, it shows a modest benefit after 1 month, though I have seen no publications about its benefits.

However, in 2021, GRG reported new benefits: According to NIH, glucosamine reduces inflammation 17%.
Paul - Glucosamine displays a potent caloric restriction mimetic effect in senescent rats by activating mitohormesis. Glucosamine is an inexpensive supplement that I have been taking for at least 20 years because it helps with joints, ligaments, tendons, etc. However, this very important additional benefit is totally new to me.