Teriparatide & Abaloparatide — Bone-Building Therapies

• How teriparatide and abaloparatide stimulate new bone growth
• Who benefits most from these bone-building treatments
• What daily self-injection involves (it is easier than you think)
• Common side effects and how to manage them
• How these medications can support bone healing after fractures and surgery
• Why you must follow up with a bone-protecting medication afterward

Teriparatide is a synthetic version of a portion of parathyroid hormone (PTH) — a natural hormone your body already produces. Abaloparatide is a related molecule that works in a similar way.

When given as a brief daily pulse (a small injection once a day), these medications stimulate your osteoblasts to build new bone more actively. This is different from most other osteoporosis drugs, which slow bone loss. Teriparatide and abaloparatide actually increase bone mass and improve bone structure.

Think of it like this: if your bones are a house that has become run-down, most medications focus on stopping further deterioration. Teriparatide and abaloparatide go further — they bring in a construction crew to build new rooms, reinforce the foundation, and strengthen the walls.

Teriparatide and abaloparatide are among the few medications that actually build new bone. For people with severe osteoporosis, this can be life-changing.

Both medications work through similar pathways, but there are some differences:

Both are effective. Your doctor will choose based on your specific needs, health profile, and insurance coverage.

These bone-building medications are typically reserved for people with:

• Severe osteoporosis (very low bone density, T-score well below -2.5)
• Multiple vertebral fractures or a history of fractures despite other treatments
• Very high fracture risk, where rapid bone strengthening is needed
• Failure of other treatments — if bisphosphonates or denosumab have not provided adequate protection

In current guidelines from the NOF and AACE, anabolic agents like teriparatide and abaloparatide are recommended as first-line treatment for very high-risk patients — before starting bone-protecting medications.

Both teriparatide and abaloparatide are given as a daily self-injection using a pre-filled pen device. If the idea of giving yourself a daily injection sounds daunting, you are not alone — but most patients find it much easier than expected.

What the injection is like:

• The pen device is similar to an insulin pen — small, lightweight, and easy to use
• The needle is extremely fine (much thinner than a sewing needle)
• You inject just under the skin of your abdomen (belly) or thigh
• The injection takes just a few seconds
• Most people describe the sensation as a small pinch or barely noticeable

Practical tips:

• Inject at roughly the same time each day
• Rotate your injection site — do not inject in the same spot every day
• Store the pen in the refrigerator
• Your pharmacist or nurse can give you a hands-on demonstration before you start

For a detailed, step-by-step guide with tips from real patients, see our self-injection guide.

Treatment with teriparatide or abaloparatide lasts up to 2 years (24 months). Think of it as a marathon, not a sprint:

• Months 1-3: Your body begins responding. Bone formation markers rise in blood tests, but you will not feel any difference yet.
• Months 3-12: Bone density gradually increases. Your doctor will track progress with blood tests and periodic bone density scans.
• Months 12-24: Continued bone building. The gains are cumulative — the longer you continue (up to 24 months), the more bone you build.

Why only 2 years? In long-term animal studies, very prolonged exposure was associated with bone tumors (osteosarcoma). While this has not been observed in human patients, a 2-year limit was established as a precaution. This time limit is the same for both teriparatide and abaloparatide.

• Nausea — usually mild and often improves over the first few weeks
• Dizziness or lightheadedness — typically occurs shortly after injection. Sitting or lying down for a few minutes after your injection can help.
• Leg cramps — may occur, especially early in treatment
• Injection site reactions — mild redness or soreness
• High calcium levels (hypercalcemia) — your doctor will monitor your calcium with blood tests. This is less common with abaloparatide than with teriparatide.

Most side effects are mild and tend to improve as your body adjusts. If you experience persistent nausea or dizziness, talk to your doctor — simple strategies (like injecting at bedtime or lying down afterward) can often help.

One of the most exciting applications of teriparatide is its potential to enhance bone healing — particularly relevant for patients who need spinal surgery.

After vertebral fractures:

• Teriparatide has been shown to reduce pain and improve outcomes in patients with vertebral compression fractures
• The bone-building effect may help the fractured vertebra heal more effectively

Supporting spinal fusion surgery:

• Research by Hadji (2012) and Ebata (2017) suggests that teriparatide may improve the success rate of spinal fusion procedures in patients with osteoporosis
• By strengthening the bone around surgical implants, teriparatide may reduce the risk of screws loosening or the fusion failing
• If you are scheduled for spinal surgery and have osteoporosis, ask your surgeon whether perioperative teriparatide might benefit you

Post-fracture pain:

• Some studies suggest that teriparatide can help reduce pain after vertebral compression fractures, possibly by promoting faster healing

If you have had a fracture or are facing spinal surgery, ask your doctor whether a bone-building medication like teriparatide could support your recovery.

This is critically important: The bone you build during teriparatide or abaloparatide treatment will gradually be lost if you do not follow up with a bone-protecting medication.

After completing your 2-year course, your doctor will transition you to a bone-protecting medication such as:

• A bisphosphonate (alendronate, risedronate, or zoledronic acid)
• Denosumab

This follow-up treatment "locks in" the bone you built — like sealing and weatherproofing a newly renovated house. Without it, the renovation starts to fade.

Research consistently shows that patients who transition to an antiresorptive medication after completing anabolic therapy maintain their bone density gains and continue to be protected against fractures.

• If you are starting self-injection, ask your pharmacist or nurse for a hands-on demonstration — and read our self-injection guide
• Inject at a consistent time each day — many patients find bedtime easiest (it also helps if dizziness is an issue)
• Rotate injection sites to minimize skin irritation
• Keep all follow-up appointments — your doctor needs to monitor your calcium levels and bone density
• Stay committed to the full course — the benefits build over time, and stopping early means less bone gained
• Plan ahead for what comes next — ask your doctor about the medication you will take after your anabolic treatment ends
• Continue calcium and vitamin D as recommended — they provide the raw materials your bones need to build

Q: Is the daily injection really necessary? Is there a pill version? A: Currently, teriparatide and abaloparatide are only available as injections. The daily pulse of the hormone is what stimulates bone formation — oral delivery cannot replicate this effect. The good news is that the injection is quick and nearly painless with modern pen devices.

Q: Can I take teriparatide if I have already been on a bisphosphonate? A: Yes. In fact, many patients switch to teriparatide after taking bisphosphonates. However, starting with teriparatide first (before bisphosphonates) may produce better results, which is why current guidelines recommend anabolic therapy first for very high-risk patients.

Q: What if I miss a day? A: If you miss a dose, simply take it when you remember (as long as it is the same day). If you miss an entire day, skip that dose and continue with your regular schedule the next day. Do not take a double dose. Occasional missed doses will not undo your progress, but try to be as consistent as possible.

Q: Is there a risk of bone cancer? A: In animal studies using very high doses for extended periods, bone tumors (osteosarcoma) were observed. However, after more than 20 years of use in millions of patients worldwide, there has been no confirmed increase in osteosarcoma risk in humans. The 2-year treatment limit provides an additional safety margin.

Q: Will my insurance cover teriparatide or abaloparatide? A: Coverage varies by plan. These medications can be expensive, but many insurers cover them for patients who meet specific criteria (severe osteoporosis, prior fracture, failure of other treatments). Your doctor's office can help with prior authorization, and manufacturer patient assistance programs may also be available.

• Neer RM, et al. Effect of Parathyroid Hormone (1-34) on Fractures and Bone Mineral Density in Postmenopausal Women with Osteoporosis. N Engl J Med. 2001;344(19):1434-1441.
• Miller PD, et al. Effect of Abaloparatide vs Placebo on New Vertebral Fractures in Postmenopausal Women with Osteoporosis (ACTIVE trial). JAMA. 2016;316(7):722-733.
• Hadji P, et al. The Effect of Teriparatide Compared with Risedronate on Reduction of Back Pain in Postmenopausal Women with Osteoporotic Vertebral Fractures. Osteoporos Int. 2012;23:1141-1150.
• Ebata S, et al. Role of Weekly Teriparatide Administration in Osseous Union Enhancement within Six Months After Posterior or Transforaminal Lumbar Interbody Fusion for Osteoporosis-Associated Lumbar Degenerative Disorders. J Bone Joint Surg Am. 2017;99:365-372.
• National Osteoporosis Foundation (NOF). Clinician's Guide to Prevention and Treatment of Osteoporosis. 2021.
• International Osteoporosis Foundation (IOF). Patient Resources: Bone-Building Medications. 2023.

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