There is no single best medication for osteoporosis. The right choice depends on how high your fracture risk is, whether you’ve already broken a bone, and how you feel about taking a daily pill versus getting an injection a few times a year. That said, the treatment landscape breaks into two clear categories: drugs that slow bone loss (antiresorptives) and drugs that actively build new bone (anabolic agents). Most people start with an antiresorptive, but if your risk is very high, starting with a bone-building drug first produces better outcomes.
Antiresorptive Drugs: The Most Common Starting Point
Antiresorptive medications work by slowing the cells that break down bone. This lets your skeleton hold onto more mineral, gradually increasing bone density over time. The two main options here are bisphosphonates and denosumab.
Bisphosphonates are the most widely prescribed osteoporosis drugs in the world. Alendronate alone accounts for about 70% of all osteoporosis prescriptions among Medicare beneficiaries. The reason is straightforward: it has decades of data behind it, it prevents fractures effectively, and generic versions cost very little. You take it as a weekly pill, first thing in the morning on an empty stomach, then stay upright and wait at least 30 minutes before eating. Other bisphosphonates include risedronate (also a weekly pill) and zoledronic acid, which is given as an intravenous infusion once a year for those who prefer not to deal with the oral dosing routine or can’t tolerate pills.
Denosumab is an injection given every six months at your doctor’s office. A 2024 comparative study found that patients newly treated with denosumab experienced a 39% lower risk of major osteoporotic fracture, a 36% lower risk of hip fracture, and a 43% lower risk of other non-vertebral fractures compared to those on alendronate. That’s a meaningful advantage. However, denosumab has an important catch: if you stop taking it, bone loss can rebound rapidly, sometimes within months. You need to transition to a bisphosphonate before discontinuing. In early 2024, the FDA also added a boxed warning about severe low calcium levels in patients with advanced kidney disease taking denosumab.
A new development worth knowing about: the FDA recently approved the first interchangeable biosimilar to Prolia (the brand name for denosumab). Called Jubbonti, it could lower costs for patients who need this drug, since branded denosumab has historically run around $1,000 per month.
Bone-Building Drugs for Very High Risk
If you’ve already had a fracture (especially a spine fracture), have very low bone density scores, or have broken a bone within the past two years, you may be classified as “very high risk.” The U.S. Endocrine Society defines this as having multiple spine fractures with a bone density T-score of -2.5 or lower. UK guidelines use a slightly different threshold, flagging a T-score of -4.0 at the spine regardless of fracture history.
For these patients, guidelines now recommend starting with an anabolic (bone-building) agent rather than an antiresorptive. The reason is biological: antiresorptives slow bone breakdown but can’t rebuild deteriorated bone architecture. Anabolic drugs stimulate the cells that form new bone, partially restoring the internal structure that osteoporosis has damaged. This is something no antiresorptive can do.
Three bone-building drugs are currently available:
- Teriparatide: A daily self-injection for up to two years. In clinical trials, it increased spine bone density by about 10% and hip density by 3 to 5% compared to placebo.
- Abaloparatide: Also a daily self-injection for up to two years. It produced nearly 12% gains at the spine and about 4% at the hip over 18 months, with slightly better hip results than teriparatide in head-to-head comparisons.
- Romosozumab: A monthly injection given for one year. It works through a different mechanism, both building bone and slowing its breakdown simultaneously. It carries a cardiovascular warning, so it’s generally avoided in people with recent heart attack or stroke.
The critical point with all three: once you finish the bone-building phase, you must follow up with an antiresorptive drug (typically a bisphosphonate or denosumab) to maintain the gains. Skipping this step means losing the new bone you built. The sequence matters too. Studies consistently show that starting with an anabolic agent and then switching to an antiresorptive produces better results than the reverse order.
Cost Differences Are Substantial
Generic alendronate is remarkably cheap. It represents 70% of all osteoporosis prescriptions but only 10% of total spending. Bisphosphonates as a class account for 83% of prescriptions and just 33% of costs.
The bone-building drugs sit at the opposite end. Teriparatide (brand name Forteo) averaged around $2,500 per month, and though it made up only 1% of prescriptions, it accounted for 23% of all osteoporosis drug spending. Denosumab at roughly $1,000 per month was similarly disproportionate. Together, these two drugs represented less than 2% of prescriptions but 27% of total costs. The approval of biosimilar denosumab may help close some of that gap, but bone-building agents remain expensive, and insurance coverage varies.
Hormone Therapy for Younger Postmenopausal Women
The 2024 UK national osteoporosis guideline now recommends hormone replacement therapy as a first-line option for younger postmenopausal women who have high fracture risk but low baseline risk for side effects like blood clots or breast cancer. This is a notable shift. For women in their 50s who are already experiencing menopause symptoms, HRT can protect bone while also addressing hot flashes, sleep disruption, and other quality-of-life issues. It’s not appropriate for everyone, but for the right candidate, it handles two problems at once.
How Long You’ll Stay on Treatment
Bisphosphonates are unique among osteoporosis drugs because they embed in bone and keep working after you stop. This makes “drug holidays” possible. After 5 years on alendronate or risedronate, or 3 years on zoledronic acid (the annual infusion), your doctor may consider pausing treatment. How long that pause lasts depends on your risk level. For people at lower risk, a holiday can last 3 to 5 years or even indefinitely. For moderate-risk patients, 2 to 5 years is typical. During the break, your bone density and sometimes blood markers are monitored, and treatment restarts if density drops back toward pre-treatment levels or you fracture.
Denosumab does not allow for holidays. Its effects wear off quickly, and stopping without transitioning to a bisphosphonate can trigger a rebound of rapid bone loss and even vertebral fractures. Bone-building agents have built-in time limits: teriparatide and abaloparatide are capped at two years, romosozumab at one year.
Rare but Serious Side Effects
Two rare complications get the most attention: atypical femur fractures and osteonecrosis of the jaw. Both are associated with long-term use of potent antiresorptive drugs, including bisphosphonates and denosumab.
Atypical femur fractures are unusual breaks in the thighbone that occur with minimal trauma, often preceded by a dull ache in the thigh. A national review in Sweden identified 172 cases over three years in a population that experienced 43,000 typical hip fractures during the same period. That’s a very low rate relative to the fractures these drugs prevent, but the risk increases with longer treatment duration, which is one reason drug holidays exist.
Osteonecrosis of the jaw, where a section of jawbone fails to heal after dental work, is even rarer at osteoporosis doses. Danish national data estimated 2.5 cases per 10,000 patient-years for oral bisphosphonates. The risk is roughly ten times higher in cancer patients receiving much larger doses. Neither atypical fractures nor jaw problems were reported in clinical trials of abaloparatide, and romosozumab showed only rare, balanced cases compared to placebo.
Kidney Function Matters
If you have reduced kidney function, your options narrow. The FDA contraindicates zoledronic acid (the IV bisphosphonate) in patients with creatinine clearance below 35 mL/min. Oral bisphosphonates carry similar cautions at that threshold. Denosumab does not rely on kidney clearance and can be used in kidney disease, but requires close calcium monitoring, especially in advanced cases, due to the risk of severe low calcium levels. Your doctor will check kidney function before prescribing any osteoporosis medication.