If you've been diagnosed with osteoporosis — or with osteopenia plus high fracture risk — your doctor may recommend pharmacological treatment alongside calcium, vitamin D, and exercise. Canada has a robust lineup of approved osteoporosis medications, from affordable generic bisphosphonates to newer bone-building agents. Here's what each one does, how it's covered, and what to expect.
Not everyone with low bone density needs medication. Osteoporosis Canada's clinical guidelines recommend pharmacological treatment primarily based on fracture risk, not T-score alone. The FRAX tool (adapted for Canadian population data) estimates 10-year probability of major osteoporotic fracture and hip fracture specifically. Treatment is generally recommended when:
Bisphosphonates are the most widely prescribed osteoporosis medications in Canada. They work by slowing bone resorption — the process by which osteoclasts break down bone tissue. By inhibiting this process, bisphosphonates allow osteoblasts (bone-building cells) to gain ground, gradually increasing bone mineral density. They are generally the first medications tried due to their strong evidence base, long safety record, and low cost.
Alendronate 70 mg taken once weekly is the most common first-line osteoporosis medication in Canada. It reduces vertebral fracture risk by about 47% and hip fracture risk by about 51% in postmenopausal women with osteoporosis. Generic alendronate is covered under most provincial drug benefit programs (ODB in Ontario, Pharmacare in BC, Trillium and others) at minimal or no cost for eligible seniors.
How to take it: First thing in the morning on an empty stomach, with a full glass of plain water. Remain upright for at least 30 minutes and do not eat or take other medications. This reduces the risk of esophageal irritation.
Common side effects: Heartburn, esophageal discomfort, abdominal pain. These are usually manageable with correct administration.
Rare but serious concerns: Osteonecrosis of the jaw (ONJ) and atypical femoral fractures are rare, with estimated rates far below the fracture risks of untreated osteoporosis. Risk is highest with prolonged use (>5 years) and in people on high-dose IV bisphosphonates for cancer treatment — the doses used in osteoporosis are much lower.
Risedronate is an alternative bisphosphonate for patients who cannot tolerate alendronate. Available as 35 mg weekly or 150 mg monthly. Efficacy is similar to alendronate — roughly 40–50% vertebral fracture risk reduction. Risedronate DR (delayed-release) can be taken with breakfast, which is useful for patients who struggle with the fasting requirement of conventional bisphosphonates.
Zoledronic acid 5 mg is given as a 15-minute intravenous infusion once per year — making adherence a non-issue compared to daily or weekly oral pills. The HORIZON trial showed a 41% reduction in hip fractures and a 70% reduction in vertebral fractures. It is the treatment of choice for patients who cannot tolerate oral bisphosphonates or who have difficulty adhering to weekly dosing.
Coverage varies by province. In Ontario, it's listed on the ODB formulary for patients who have tried oral bisphosphonates. BC Pharmacare provides Special Authority coverage. The infusion is often administered in a hospital outpatient clinic or by a home infusion service.
Side effects: An acute-phase reaction — fever, muscle aches, flu-like symptoms — occurs in about 30% of patients after the first dose and typically resolves in 1–3 days. Subsequent infusions rarely cause this reaction. Taking acetaminophen or ibuprofen around the time of infusion reduces this effect.
Bisphosphonates accumulate in bone over time. After 5 years of oral therapy (or 3 years of annual IV zoledronic acid), many guidelines recommend reassessing fracture risk and considering a drug holiday — a structured pause in treatment. This is particularly relevant because prolonged bisphosphonate use is the primary risk factor for atypical femoral fractures, though the absolute risk remains low (about 3–9 per 10,000 patient-years).
Patients at high fracture risk — those with T-scores below −2.5, prior fractures, or high FRAX scores — may need to continue or switch to a different medication. Learn more on our dedicated bisphosphonate drug holiday page.
Denosumab is a monoclonal antibody that inhibits RANKL, a protein that activates bone-resorbing osteoclasts. Given as a subcutaneous injection every six months, it significantly reduces vertebral fractures (68%) and hip fractures (40%) in postmenopausal women. It is also approved for men and for glucocorticoid-induced osteoporosis.
Denosumab is often used when bisphosphonates are not tolerated, are contraindicated (e.g., in patients with significant kidney impairment, where bisphosphonates cannot be used), or have not provided adequate response.
Critical consideration — stopping Prolia: Unlike bisphosphonates, denosumab does not accumulate in bone. When it is stopped, bone resorption accelerates rapidly and can result in multiple vertebral fractures — a phenomenon called rebound. Patients stopping denosumab must transition to a bisphosphonate immediately. This is a serious and often under-communicated risk. See our full article on stopping Prolia and rebound fracture risk.
Provincial coverage: Most provincial drug benefit programs cover Prolia with Special Authority criteria, typically requiring failure or intolerance of bisphosphonates. The injection is given by a healthcare provider (doctor, nurse, or pharmacist in provinces with injection authority).
The medications above work by slowing bone breakdown. Anabolic agents take a different approach — they actively stimulate new bone formation. They are reserved for patients with severe osteoporosis (very low T-scores, multiple fractures, or very high fracture risk) and are typically given before or alongside antiresorptive therapy.
Romosozumab is a newer dual-action monoclonal antibody that both stimulates bone formation and reduces bone resorption simultaneously. It is given as two subcutaneous injections once monthly for 12 months, then followed by antiresorptive therapy. Clinical trials showed remarkable fracture reduction: in the ARCH trial, 12 months of romosozumab followed by alendronate reduced hip fractures by 38% compared to alendronate alone from the start.
Cardiovascular caution: Romosozumab carries a Health Canada warning for increased risk of serious cardiovascular events (heart attack, stroke). It should not be used in patients who have had a heart attack or stroke within the past year. This is an important discussion to have with your doctor.
Coverage varies; most provinces require prior failure or intolerance of bisphosphonates and denosumab, and a T-score below −2.5 with at least one fragility fracture.
Teriparatide is a synthetic parathyroid hormone fragment injected daily via a pen device for up to 24 months. It stimulates osteoblast activity and has strong fracture-reduction data, particularly for vertebral fractures (65% reduction) and non-vertebral fractures (53% reduction). It is approved for severe osteoporosis in postmenopausal women and men.
A biosimilar teriparatide is now available in Canada, reducing costs substantially. Coverage through provincial drug plans generally requires prior bisphosphonate therapy, severe osteoporosis (T-score ≤−3.0 or multiple fractures), and physician justification.
| Medication | Ontario ODB | BC Pharmacare | Alberta NIHB |
|---|---|---|---|
| Generic alendronate | Listed (LU code) | Formulary | Covered |
| Risedronate | Listed | Formulary | Covered |
| Zoledronic acid (Aclasta) | Listed (LU code) | Special Authority | Special Auth |
| Denosumab (Prolia) | Exceptional Access | Special Authority | Special Auth |
| Romosozumab (Evenity) | Limited (criteria) | Special Authority | Special Auth |
| Teriparatide (Forteo) | Exceptional Access | Special Authority | Special Auth |
Coverage details change regularly. Check your provincial formulary or ask your doctor or pharmacist to submit a Special Authority or prior authorization request on your behalf.