Anabolics: The Bone Builders. Evenity, Forteo, and Tymlos
Build New Bone
You will feel confident about starting an osteoporosis medication if you have a solid understanding of what you are about to take. Previously, I wrote about bisphosphonates, which work by slowing bone breakdown, and Prolia, which also slows bone breakdown but in a very different way.
While slowing bone loss is enough for some women, it might not be enough for women with significant bone loss or who have already sustained multiple fractures. This is where another group of medications comes in, medications that build new bone.
Evenity, Forteo, and Tymlos are bone builders. They are known as anabolic medications, and they are prescribed for women with a high fracture risk or advanced bone loss.
These medications are different from bisphosphonates and Prolia:
They are meant to be taken for a specific amount of time, and should be followed by another medication to maintain the bone gains.
Understanding how they work — and what must come after them — is essential.
What Are Bone-Building (Anabolic) Medications?
Bone-building medications, or anabolic medications, encourage your body to build new bone. They work by stimulating osteoblasts, the cells that create new bone.
Instead of simply slowing bone breakdown (by inhibiting osteoclasts), these medications help you add new bone. This makes them especially useful when:
Bone density is very low
Fracture risk remains high despite other therapies
Fragility fractures have already occurred
Other medications have not been enough
However, the bone gained with these anabolic medications can be lost if a follow-up plan is not in place.
Evenity: Building Bone and Reducing Bone Breakdown
Medication name: Romosozumab. FDA approved 2019
How it works: Evenity does two things: It stimulates osteoblasts to build new bone while modestly reducing bone breakdown.It works by blocking sclerostin, a protein produced by bone cells that normally limits bone formation. When sclerostin is blocked, osteoblast activity increases and bone can be built more rapidly.
How it’s given:
Monthly injections (two injections per visit, given by your healthcare provider, into the abdomen, thigh or upper arm)
Approved for 12 months of use only
Why it’s prescribed:
Very low bone density
Multiple vertebral fractures
Very high fracture risk
Need for faster bone-building effects
Evenity is most effective when used as part of a sequential treatment plan — meaning it is started first, followed by another osteoporosis medication to maintain the bone gained.
A large 2025 meta-analysis (Li et al. 2025) found that romosozumab, followed by an antiresorptive medication (such as alendronate or denosumab), significantly reduced vertebral, non-vertebral, and hip fractures, while also producing meaningful increases in bone density at the spine and hip.
What comes next:
A bisphosphonate (such as alendronate or zoledronic acid), or
Prolia (denosumab)
This step helps “lock in” the gains made during the bone-building phase.
Safety note: Evenity is the only anabolic medication that has a black box warning about the increased risk of a cardiovascular event (heart attack, stroke).
Forteo: Stimulating New Bone Formation
Medication name: Teriparatide. The first anabolic, FDA approved in 2002
How it works: man-made form of Parathyroid hormone (PTH)
Forteo works by stimulating parathyroid hormone receptors, which signal the body to increase osteoblast activity which will build new bone.
How it’s given:
Daily self-injection into the thigh or abdomen
Approved for up to 2 years of total use
Why it’s prescribed:
Severe osteoporosis
Prior fractures
Failure or intolerance of other therapies
Like Evenity, Forteo must be followed by another medication to preserve the bone gained.
Tymlos: Activating Bone-Building Cells
Medication name: Abaloparatide. FDA approved in 2017.
How it works: Similar to Forteo, but with slightly different receptor binding
Tymlos also works to stimulate osteoblasts with parathyroid hormone receptors.
How it’s given:
Daily self-injection to the lower stomach area
Approved for up to 2 years, 24 months total over a lifetime
Why it’s prescribed:
High fracture risk
Need for anabolic therapy
Alternative to Forteo
As with the other anabolic medications, follow-up with an antiresorptive therapy is required to lock in the bone gains.
Key Takeaways
Evenity, Forteo, and Tymlos are powerful medications for building bone. They can be effective, first-line medications for you if you are at a high risk of fracturing or have already experienced fractures. When they are taken as recommended— and followed by the right maintenance medication — they can significantly reduce your fracture risk and improve your bone density.
Understanding how these medications work, how long they’re used, and what comes next can help you feel more confident and prepared when discussing your treatment plan with your physician.
As always, medications work best when paired with consistent strength training, balance work, and thoughtful movement. I want you to know that your exercise routine, including progressively heavier lifting, as well as excellent nutrition, is essential for stimulating bone growth.
Join my next Strong Women, Strong Bones Jumpstart to gain a solid base and get started.
This post is part of a short series explaining how osteoporosis medications work — from slowing bone loss, to suppressing resorption, to building new bone
Andrea Trombley DPT
References
Drugs.com Evenity. Forteo. Tymlos. https://www.drugs.com/evenity.html#uses
Händel MN, Cardoso I, von Bülow C, Rohde JF, Ussing A, Nielsen SM, Christensen R, Body JJ, Brandi ML, Diez-Perez A, Hadji P, Javaid MK, Lems WF, Nogues X, Roux C, Minisola S, Kurth A, Thomas T, Prieto-Alhambra D, Ferrari SL, Langdahl B, Abrahamsen B. Fracture risk reduction and safety by osteoporosis treatment compared with placebo or active comparator in postmenopausal women: systematic review, network meta-analysis, and meta-regression analysis of randomised clinical trials. BMJ. 2023 May 2;381:e068033. doi: 10.1136/bmj-2021-068033. PMID: 37130601; PMCID: PMC10152340.
Li T, Zheng W, Zhang Q, Liao M, Jin L, Wu F, Zhou F, Wang Y, Gong W, Xia Y, Lin Z, Xiong X, He Y, Ye J, Huang J. The efficacy and safety of romosozumab sequential therapy in postmenopausal women: A systematic review and meta-analysis. J Orthop. 2025 Oct 30;72:152-159. doi: 10.1016/j.jor.2025.10.014. PMID: 41340723; PMCID: PMC12671032.
Takeuchi Y. Cardiovascular safety of osteoanabolic agents. J Bone Miner Metab. 2025 Jan;43(1):26-32. doi: 10.1007/s00774-025-01580-4. Epub 2025 Jan 17. PMID: 39825110; PMCID: PMC11954844.
Veronese N, Briot K, Guañabens N, Albergaria BH, Alokail M, Al-Daghri N, Bemden AB, Bruyère O, Burlet N, Cooper C, Curtis EM, Ebeling PR, Halbout P, Hesse E, Hiligsmann M, Camargos BM, Harvey NC, Perez AD, Radermecker RP, Reginster JY, Rizzoli R, Siggelkow H, Cortet B, Brandi ML. Recommendations for the optimal use of bone forming agents in osteoporosis. Aging Clin Exp Res. 2024 Aug 9;36(1):167. doi: 10.1007/s40520-024-02826-3. PMID: 39120740; PMCID: PMC11315730.