mint, https://pmc.ncbi.nlm.nih.gov/articles/PMC6422956/
There is a subset of individuals who continue to maintain coupled bone markers longer than 24 months. Most of the studies are just to 18 months where you see at somewhere approaching 18 month there is this increase in CTX without the accompanying P1NP. If you are wondering about staying on Tymlos longer than 18 months, it is best to have you bone markers tested. There are doctors prescribing longer terms of treatment with both Forteo and Tymlos. I'm starting my fourth year of Forteo, checking serum bone markers every three months.
Research isn't telling us yet why the balance changes. Maybe resource depletion. We don't even know it the shift is transient. And if a person were to continue the medication after the decline we don't know if it would rise again. The pth drugs have my favored mechanism, so I'd like to remain on Forteo or Tymlos and avoid all the others.