Most osteoporosis medications slow bone loss. Teriparatide (Forteo/Osnuvo) and romosozumab (Evenity) actually build new bone. They're more expensive, more complex, and reserved for people with severe or treatment-resistant osteoporosis — but for the right patient, they can be dramatically more effective than anything else available.
Every osteoporosis medication you've heard of fits into one of two categories, and the distinction matters enormously.
Antiresorptive medications — bisphosphonates like alendronate (Fosamax) and risedronate (Actonel), plus denosumab (Prolia) — work by slowing down osteoclasts, the cells that break down bone. They preserve what you have. They don't create new bone; they slow the loss.
Anabolic medications — teriparatide (Forteo, Osnuvo) and romosozumab (Evenity) — work differently. They stimulate osteoblasts, the cells that build bone. The result is actual new bone formation, not just preservation. This is why their BMD gains are substantially larger, and why they're typically reserved for the most severe cases.
If you have a T-score of -3.5 and have already had a vertebral fracture, antiresorptives might not be enough. That's the situation where these drugs get considered. For more on antiresorptive medications in Canada, see the broader medications guide.
Teriparatide is a synthetic fragment of parathyroid hormone (PTH). Your body naturally uses PTH to regulate calcium — teriparatide hijacks that system to drive bone formation.
You inject it yourself, once daily, using a prefilled pen device. The treatment course is capped at two years. That limit exists because preclinical animal studies (very high doses in rats) showed increased osteosarcoma rates, though this has not been confirmed in human patients after decades of use. Regardless, the two-year maximum is maintained worldwide.
Clinical trials show teriparatide increases lumbar spine BMD by approximately 9–13% over two years. That's meaningful. Compare that to alendronate at roughly 5–8% over the same period.
For hip BMD, the gains are more modest — typically 3–6%. But the fracture risk reduction is real: teriparatide reduces vertebral fracture risk by about 65% in women with severe osteoporosis.
The original Forteo brand costs roughly $10,000–$14,000 for a two-year course in Canada. That's a significant barrier.
Osnuvo is a Health Canada-approved biosimilar of teriparatide, available in Canada since 2022. It has the same clinical profile as Forteo at a lower cost. Most provincial drug plans that cover teriparatide have added Osnuvo, typically under special authority criteria. In BC, Osnuvo is listed on PharmaCare with special authority for patients with severe osteoporosis (T-score ≤ -3.0 or prior fragility fracture).
If your doctor is prescribing teriparatide and cost is a concern, ask specifically about Osnuvo and whether your provincial plan covers it with special authorization.
The most common side effects are mild: dizziness or light-headedness after the first few injections (sit down after your first dose), nausea, a metallic taste, and leg cramps. These typically improve after the first few weeks.
Because it transiently raises calcium, your doctor will likely check your calcium and kidney function before starting. Teriparatide is contraindicated if you have hypercalcemia, Paget's disease, prior radiation to the skeleton, or a history of bone cancer.
Romosozumab is genuinely different from everything else in the osteoporosis toolkit. It's a sclerostin inhibitor — it blocks a protein that acts as a brake on bone formation. When that brake is released, bone formation goes up. At the same time, it reduces bone resorption. No other osteoporosis drug does both simultaneously.
The treatment course is 12 months of monthly injections given by a healthcare provider — not self-administered. After the 12-month course, you transition to an antiresorptive medication (typically denosumab or a bisphosphonate) to preserve the gains.
The ARCH trial compared romosozumab followed by alendronate versus alendronate alone. After 24 months, the romosozumab group had significantly higher BMD and a 48% lower risk of new vertebral fractures than the alendronate-only group. A head-to-head comparison with teriparatide showed larger BMD gains at 12 months for romosozumab.
In absolute terms: lumbar spine BMD gains of approximately 13% over 12 months, femoral neck gains around 6%. For reference, that's roughly double what antiresorptives typically achieve.
Romosozumab carries a Health Canada black box warning for cardiovascular risk. In the ARCH trial, the romosozumab group had a slightly higher rate of serious cardiovascular events (heart attack, stroke) compared to alendronate — 2.5% vs 1.9% over 12 months.
The absolute numbers were small and the trial enrolled older patients with established cardiovascular risk factors. But the warning is real. Evenity is contraindicated if you've had a heart attack or stroke within the past year. If you have significant cardiovascular risk factors, your cardiologist and GP should both weigh in before starting.
This is where Canadian patients face the biggest challenge. Evenity costs approximately $7,900–$8,500 per year in Canada based on BC PharmaCare list pricing. It is currently listed as "non-benefit" on BC PharmaCare — meaning it's not covered by the provincial plan and patients pay out of pocket or through private insurance.
CADTH (the Canadian Drug Review body) issued a conditional reimbursement recommendation for romosozumab — meaning they found it cost-effective only for patients at very high fracture risk. The evidence for coverage in real-world provincial plans is still catching up.
Amgen (the manufacturer) operates the One-to-One patient support program in Canada. This program can assist with navigating private insurance special authorization, connecting patients with reimbursement specialists, and sometimes providing financial assistance. Ask your rheumatologist or endocrinologist about this program if cost is the barrier.
If you're reading US-based osteoporosis forums or websites, you'll see abaloparatide (Tymlos) mentioned as another anabolic option. It is approved by the FDA but is not approved by Health Canada and is not available in Canada as of 2026. Don't assume US drug discussions apply to your treatment options.
Both teriparatide and romosozumab have a well-documented "turn-off" problem. When you stop an anabolic agent without transitioning to an antiresorptive, you lose much of the bone you gained — relatively quickly.
After completing teriparatide, starting a bisphosphonate or denosumab within a few months is standard practice. After romosozumab, the ARCH trial used alendronate, and other trials have used denosumab. The follow-on antiresorptive consolidates the bone gains and maintains fracture risk reduction.
Failing to transition is one of the most common ways patients undermine expensive anabolic therapy. If your doctor prescribes Forteo or Evenity, ask specifically: "What medication will I take after this, and when do we start it?"
Osteoporosis Canada guidelines suggest anabolic therapy for patients who:
In practice, the choice between teriparatide and romosozumab often comes down to cardiovascular history (romosozumab is out if there's recent MI/stroke), cost and coverage, and patient preference for daily vs monthly injections.
| Feature | Teriparatide (Forteo/Osnuvo) | Romosozumab (Evenity) |
|---|---|---|
| Mechanism | PTH analogue — stimulates bone formation | Sclerostin inhibitor — builds bone + reduces resorption |
| Administration | Daily self-injection (20 mcg) | Monthly injection by healthcare provider (210 mg) |
| Treatment duration | Max 24 months (lifetime) | 12 months |
| Spine BMD gain | ~9–13% over 2 years | ~13% over 12 months |
| Key contraindications | Bone cancer/radiation history, Paget's disease, hypercalcemia | MI or stroke within past year |
| Canadian coverage | Osnuvo biosimilar: covered with special authority (most provinces) | ~$7,900–8,500/year; non-benefit BC; private insurance or patient support program |
| Common side effects | Dizziness (first dose), nausea, metallic taste, leg cramps | Injection site reactions, joint/back pain |
Both medications require adequate calcium and vitamin D to work. Bone formation without sufficient mineral supply is like framing a house without any lumber. Osteoporosis Canada recommends 1,200 mg calcium daily (diet plus supplements) and 800–2,000 IU vitamin D for people on bone-active medications. See the vitamin D guide and calcium guide for specifics.
If your provincial drug plan doesn't cover the medication your doctor recommends, the options are: private employer drug plan (special authorization is usually required — your doctor's office can initiate this), manufacturer patient support programs (Amgen One-to-One for Evenity; Eli Lilly Canada has a program for Forteo), or provincial exceptional access/special authority applications that your specialist can submit on your behalf.
The key is not giving up. These pathways exist specifically because these drugs are expensive and provinces have criteria-based access programs. Your rheumatologist or endocrinologist's office will typically know the process for your province.