I’ve recently been told (albeit by the singer in one of my bands, who has been a nurse for 30+ years) that my knee pain and discomfort is osteoarthritis. She said to try ibuprofen but then said a better bet (for reasons already alluded to above) was MSM, which you can get from Holland and Barrett. I’ll be honest, a week and a bit on from starting to use MSM it’s not really done anything for me yet but I’m wondering if it may just take a bit longer to kick in. We’ll see - I’ll report back in another week
PS - I’m 41 so not too dissimilar an age from you @NasalFloss