Has anyone had a drop in their bone scans while on forteo?

redlo, I'm on Forteo (third year). My bone density was slower than yours to respond. Forteo gets busy reconstructing cartilage which doesn't appear on dexa. My second year dexa was better.
There are a few things to consider. Your weakest areas in in the trabecular bone in the spine and in the femur. Forteo is thought to work better in trabecular bone than any other medication including Tymlos. If you had TBS it would probably reflect reduced fracture risk because it attempts to calculate the microarchitecture in trabecular bone.
Tymlos would be effective and would get all the credit for the hard work Forteo has done, but you may not have horrible side effects with Tymlos. That "might" alone would make it worth trying Tymlos.
Strangely some of these medications aren't effective for some people. So there is that possibility.
One concern is that you've been on the medication and you are still having side effects. Sometimes Forteo serves as a warning that we should test to see if there are secondary causes of osteoporosis--namely kidney disease, or hyperparathyroidism. It could be a simple problem with too much calcium or too much D3.
I love that they are referencing the bone markers that they didn't want to order.
Bone markers have proven reliable in studies as evidence that bone repair and increase will show in increased bone density on dexa. I don't know how your doctor's method of assessment.
Have you been tracking calcium, magnesium, phosphorus, and pth.
I should lay low and let people who have switched from Forteo to Tymlos. I haven't. I'll never stop taking Forteo willingly.

@gently
Thank you so much for your reply. I scheduled a call with Dr. McCormick for advice also. It just seems so many had great results with forteo. I am a little concerned my blood work has consistently gone up high in the alkaline phosphate It's jumped from 58 to 147.
Also, Maybe Forteo slow for improvement because of the fosmax I was on before?
It is encouraging that your second year saw improvement. Thank you again for responding I feel so discouraged. Just wished I felt I had a good doctor to guide me .God bless

redlo, I was convinced that the pens were not being refrigerated somewhere in transit.
But mainly because I didn't have any side effects.
From our dearest mayblin last year
"mayblin | @mayblin | Oct 1, 2024
My ALP (serum, total) almost doubled after I started Forteo and my endo said it was normal being on Forteo. Near the end of Forteo treatment, ALP did come down to my regular normal.
I read a bit about ALP - it could come from liver, bones and other tissues. When the bone formation is ramping up while one is on an anabolic, bone specific ALP increases and this reflects the mineralization phase of bone formation. Bone specific ALP is part of total ALP hence your serum total ALP goes up on Forteo. Some endo does lab work for bone specific ALP."
Fosamax use does delay bone density increase. But it isn't stymied or wasting time. Patients with Fosamax-bones catch up by the end of the second year (in clinical trials). Forteo was my first (only) osteoporosis medication, but the bone markers were good and I really trust the mechanism of action of both the PTH 1-34 drugs.
My concern in your situation is that you are having unpleasant side effects, which may mean that your body is in a inflammatory state--not good for anyone. I'm glad you are consulting with McCormick. You might focus on the tests that could explain why you are having side effects.
I don't think you should be discouraged. You've suffered the year and earned stronger bones and high flying ALP, You are building the best bone in the world.