By what percentage did your T-scores improve after a round of TYMLOS?

@willowmena, Tymlos results aren't usually measured so early in the treatment, because of the way it works. Bones require a collagenous structure to collect mineral. Tymlos, Forteo and to lesser extent Evenity actually rebuild that structure. These three also have the ability to restore the canals in the center and at the edges of bone that carry blood, nerves, and signals throughout the bone. To build that kind of structurally sound bone the damaged bone cells have to be removed.
It is said of Tymlos and Forteo that it is important to complete the full course because of the time it takes to complete the complicated process. It is the reason that Tymlos and Forteo are the only osteoporosis not implicated in osteonecrosis of the bone. You may well be losing bone mineral at this stage of the treatment. The forfeiture should result in stronger bone.
It isn't uncommon to lose bone mineral density in the hip and femur even after two years of Tymlos. Bone mineral content isn't really a measure of bone resilience.
I'm on my fourth year of Forteo. The dexa reports haven't given me any encouragement. I have confidence in the bone markers and they look good like yours do. I think that I have more bone that needs to be replaced and more canaliculi that need restoration than most patients.
Estradiol supports the cells that build bone , but its main protective mechanism is in slowing down the cells that remove old bone. Tymlos works by increasing both. So some endocrinologist think it is counterproductive. Our doctors are worried about the possibility that estradiol increases the risk of blood clots in those of us with the stiffer vascular systems.
Medicare is now paying for a new measurement of bone health VirtuOst BCT that you might request. https://ondiagnostics.com/patients/virtuost-vs-standard-bmd-test/ (thanks to babs10) I requested it instead of my upcoming dexa minutes after I read bab's post.
It's tough when you can't exercise without incurring days of discomfort. Physical Therapy might be help.
Your worry is sensible.

After 10 months on Tymlos, my bone density per a REMS scan has decreased in my lumbar spine. At month 5, my L-1 reading was -3.3 with readings of -3.2 and -3.1 for L-2 thru L-4. This week, at month 10, I took another REMS scan (same machine and technician) and the results were so disappointing with worsening of the lumbar spine. Also the trabecular bone worsened somewhat. I had bi-lateral hip replacements years ago so no scan there. My cervical spine is also quite damaged from horseback riding fall of years ago, so DEXA scan does not read it properly. DEXA gave me a radius forearm reading of -3.2 before I began Tymlos. Will try another DEXA soon to see if the wrist has worsened but cortical wrist bone is a poor measure of overall bone health. I am continuing Tymlos for now but so very disappointed and not sure what else to do. Blood bone marker tests were okay with P1NP reaching 107 after 5 months. Doctor uses NTX rather than CTX for bone resorption measurement and it really jumped, maybe inappropriate ratio. I supplement but because of my damaged spine and neck, cannot do much in the way of exercise. Even walking on a treadmill ends in days of discomfort. At age 77, none of my doctors will agree to prescribe a low dose of HRT. I would like to try the patch. My endo claims she has not seen much in the way of bone gains from HRT. Appreciate suggestions, thoughts.

@willowmena The REM scores are not accurate. There was a recent study done which showed REM is not an accurate tool for measuring true bone density. Do a google search to find this study. DEXA is not a perfect measuring tool, but it is good enough.

See my post:
https://connect.mayoclinic.org/discussion/tymlos-results-from-dexa-scan-after-12-months/
Please do not discontinue the tymlos. My endocrinologist said she has never seem someone who took it whose bone density did not improve. It is also very important that after 24 months of tymlos, you take a bisphosphonate to lock in the gains, otherwise they will be lost.

I know your situation is more complicated than most, but I hope you are seeing a good endocrinologist. Best wishes to you, and keep us up to date on your progress!

After 10 months on Tymlos, my bone density per a REMS scan has decreased in my lumbar spine. At month 5, my L-1 reading was -3.3 with readings of -3.2 and -3.1 for L-2 thru L-4. This week, at month 10, I took another REMS scan (same machine and technician) and the results were so disappointing with worsening of the lumbar spine. Also the trabecular bone worsened somewhat. I had bi-lateral hip replacements years ago so no scan there. My cervical spine is also quite damaged from horseback riding fall of years ago, so DEXA scan does not read it properly. DEXA gave me a radius forearm reading of -3.2 before I began Tymlos. Will try another DEXA soon to see if the wrist has worsened but cortical wrist bone is a poor measure of overall bone health. I am continuing Tymlos for now but so very disappointed and not sure what else to do. Blood bone marker tests were okay with P1NP reaching 107 after 5 months. Doctor uses NTX rather than CTX for bone resorption measurement and it really jumped, maybe inappropriate ratio. I supplement but because of my damaged spine and neck, cannot do much in the way of exercise. Even walking on a treadmill ends in days of discomfort. At age 77, none of my doctors will agree to prescribe a low dose of HRT. I would like to try the patch. My endo claims she has not seen much in the way of bone gains from HRT. Appreciate suggestions, thoughts.

@willowmena You have posed a very good (and hard) question. According to Gemini:

Evaluating treatment response typically involves a combination of imaging alternatives and biochemical markers:
1. Alternative Imaging Options
Hip-Only DEXA Scans: While a full DEXA evaluates both the spine and hips, a damaged spine often skews results due to artifacts like hardware, severe degenerative changes, or compression fractures. However, a hip-only DEXA remains fully valid and interpretable. Because anabolic medications like Tymlos increase bone mineral density systemically (though to varying degrees), tracking changes at the total hip and femoral neck can provide a reliable proxy for overall skeletal response.
Quantitative Computed Tomography (QCT): QCT can assess volumetric bone mineral density (vBMD) specifically at the spine or hip. Unlike a 2D DEXA projection, QCT software can isolate specific vertebrae or avoid damaged areas, though it involves a higher radiation dose.

2. Biochemical Bone Turnover Markers (BTMs)
Because Tymlos is an anabolic (bone-building) therapy, it stimulates bone formation significantly faster than it stimulates bone resorption early in the treatment course. Blood or urine markers can show whether the medication is actively engaging bone metabolism within weeks to months—long before a density scan can register a change.

Formation Markers: Tests like P1NP (Serum procollagen type I N-propeptide) typically rise sharply within 1 to 3 months of starting an anabolic drug, confirming that the bone-building cells (osteoblasts) are responding to the treatment.
Resorption Markers: Tests like CTX (Serum C-telopeptide) measure bone breakdown. While formation should outpace resorption on Tymlos, tracking both gives a complete picture of bone turnover dynamics.

3. Clinical and Functional Tracking
Height and Posture Monitoring: Severe spinal damage often stems from silent micro-fractures or structural collapse. Tracking height accurately over time and noting any stabilization in posture can help clinically indicate that vertebral integrity is being maintained.
Incident Fracture Assessment: The ultimate clinical goal of Tymlos is fracture reduction. Vigilant tracking of new pain episodes or structural changes via diagnostic X-rays (when clinically warranted) helps ensure the spine is protected.

Are you seeing an endocrinologist? or bone specialist? They should be able to give you guidance also.

@roseincalifornia Yes I have an endo, but she may not be thinking "outside of the box". She has been my thyroid dr. for years but not clear about her bone expertise. Tried a so-called metabolic bone expert with Univ. of Miami and was very disappointed. Ordered no new blood or urine testing and suggested a new DEXA in January, this after I emphasized that my spine is too damaged for an accurate DEXA assessment, and I had bi-lateral hip replacements in 2017. Some doctors just don't listen. Maybe it is too soon to expect results from Tymlos, but losing density and trabecular health was not what I expected.

I have just been diagnosed with severe osteoporosis with a T-score of -3.3. I have a 15% chance of fracture over the next ten years. My doctor and Endo are recommending either Tymlos, Forteo or Evenity. Then 5 years of oral Fosomax or 3 years of Reclast. I am freaking out. I am 62 with all normal labs. This was my first DEXA scan. I have never had a fracture and I am very active and eat really healthy. I have never smoked and drink very moderately. Has anyone with osteoporosis stabilized their T scores without medications? I am really struggling to know what to choose. People say 3x weekly weigh bearing exercise, Tai Chi K2 supplements etc.. can help. Any suggestions?