When osteoporosis reaches a severe stage, simply slowing bone loss isn’t enough. You need to rebuild it. That’s where anabolic agents like teriparatide and abaloparatide come in. Unlike older drugs that only prevent further breakdown, these two medications actually stimulate your body to make new bone. They’re not first-line treatments for everyone, but for people with very low bone density or a history of fractures, they can be life-changing.
How These Drugs Work: Bone Building, Not Just Protection
Most osteoporosis drugs - like bisphosphonates or denosumab - work by blocking cells that break down bone. They’re like a brake pedal. Teriparatide and abaloparatide? They’re the gas pedal. Both are synthetic versions of natural hormones that tell your bones to grow.
Teriparatide is a piece of human parathyroid hormone (PTH), specifically the first 34 amino acids. It’s been around since 2002 and was the first of its kind. Abaloparatide, approved in 2017, is a lab-made copy of a different hormone called PTHrP, which is naturally found in bone. The key difference? Abaloparatide binds more selectively to the receptor on bone cells. This means it turns on bone-building signals more strongly while accidentally triggering bone-breaking signals less often.
This small biological difference leads to real-world results. In the ACTIVE trial, which tracked over 2,400 postmenopausal women, abaloparatide cut new vertebral fractures by more than 90% compared to placebo. Teriparatide did the same, but abaloparatide had a slight edge in preventing hip and other non-spine fractures.
Side Effects: Why Some People Switch
Both drugs are injected daily under the skin. Common side effects include dizziness, nausea, and injection site reactions. But one major difference stands out: hypercalcemia - elevated calcium in the blood.
In the ACTIVE trial, 6.4% of people on teriparatide had high calcium levels. Only 3.4% on abaloparatide did. That’s nearly half the rate. Why? Because abaloparatide’s selective binding means it doesn’t overstimulate the kidney and gut to pull calcium from bones and food the way teriparatide sometimes does.
Real-world data backs this up. A 2024 survey of over 1,200 patients found 32% stopped teriparatide within a year - mostly because of dizziness or high calcium. Only 24% stopped abaloparatide. One Reddit user wrote: "Switched from teriparatide to abaloparatide after persistent hypercalcemia; calcium levels normalized within 3 months while maintaining BMD gains."
That doesn’t mean abaloparatide is perfect. Some users report more dizziness, and others say they didn’t see as much improvement in spine density. But for those who can’t tolerate teriparatide’s side effects, abaloparatide is often the better option.
Which One Builds Bone Better?
Bone mineral density (BMD) is the standard measure. Both drugs increase it - but not equally.
After 18 months of treatment:
- At the total hip: Abaloparatide improved BMD by 3.41%. Teriparatide: 2.04%. That’s a 1.37% difference - statistically significant.
- At the femoral neck (a common fracture site): Abaloparatide: 2.93%. Teriparatide: 1.49%.
- At the lumbar spine: Both showed strong gains - 6.58% vs 5.25% at 6 months. By 18 months, the gap closed, but both still beat placebo.
Here’s what that means: If you’ve had a hip fracture or your hip T-score is below -3.0, abaloparatide gives you a better shot at rebuilding that area. The American Association of Clinical Endocrinologists specifically recommends abaloparatide for patients with severe hip osteoporosis.
And here’s a powerful stat: Over 50% of women starting with a total hip T-score as low as -2.7 reached a safer level above -2.5 after 18 months on either drug. That’s not just a number - it’s the difference between a high fracture risk and a moderate one.
Cost and Access: The Hidden Barrier
Cost is where this gets messy.
As of 2024, abaloparatide (Tymlos) costs about $5,750 per month. Teriparatide (Forteo) was $4,200 - but then everything changed. In January 2024, generic teriparatide hit the market. Teva Pharmaceuticals started selling it. Prices dropped nearly 40%.
Now, generic teriparatide can cost as little as $2,500 a month. Abaloparatide? Still brand-name. No generics yet. Insurance coverage is harder to get for abaloparatide - 44% of users report denials, compared to 28% for teriparatide.
So while abaloparatide has better data on hip bone growth and fewer side effects, cost often decides who gets it. Many doctors still prescribe teriparatide first - not because it’s better, but because it’s cheaper and has 20+ years of real-world use behind it.
How Long Should You Take Them?
Neither drug is meant for long-term use. The FDA limits treatment to 18-24 months total. Why? Animal studies showed a small risk of bone cancer (osteosarcoma) with very long-term use. That risk is extremely low in humans - no confirmed cases in over 20 years - but regulators still cap the duration.
That’s why sequencing matters. After 18 months, most patients switch to an antiresorptive drug like alendronate or denosumab. The ACTIVE-EXTEND trial showed this approach works: 68% of people who took abaloparatide first and then alendronate kept their hip BMD gains at 3.5 years. Those who only took alendronate from the start? Only 52% did.
It’s like building a house. You use teriparatide or abaloparatide to lay the bricks. Then you use alendronate to seal them in.
Who Gets These Drugs? Who Doesn’t?
These aren’t for everyone. They’re reserved for:
- Postmenopausal women with very low bone density (T-score ≤ -2.5) and a history of fractures
- Men with osteoporosis and high fracture risk
- People who failed other treatments
If you’ve had a hip fracture, a spine fracture, or your T-score is below -3.0 - especially at the hip - you’re a strong candidate. If you’re just starting to lose bone density and your doctor can manage it with a bisphosphonate, you probably won’t get this.
Also, these drugs aren’t safe for everyone. If you’ve had radiation therapy to the bones, Paget’s disease, or bone cancer, avoid them. They’re also not approved for children or young adults.
What’s Next? The Future of Bone Building
There’s exciting work on the horizon. Radius Health is testing a weekly version of abaloparatide. If it works, adherence could jump. Daily injections are hard. Weekly? Much easier.
The FDA is also pushing for research into extending treatment beyond 24 months. With aging populations - by 2030, 22% of Americans will be over 65 - we need better long-term options.
And the market is shifting. In 2023, teriparatide made $1.2 billion. Abaloparatide made $780 million. But with generics, teriparatide’s dominance is growing again. Still, for patients who need the best hip protection and can afford it, abaloparatide remains the gold standard.
Can I take teriparatide and abaloparatide together?
No. You should never use both at the same time. They work the same way and doubling the dose doesn’t improve results - it only increases side effects. Doctors prescribe one or the other, then switch to a different type of drug (like alendronate) after 18-24 months.
Do these drugs cure osteoporosis?
No. They don’t cure it. They rebuild bone and reduce fracture risk significantly during treatment and for a period after. But bone density can drop again if you stop and don’t follow up with an antiresorptive drug like alendronate. Think of them as a powerful reset button - not a permanent fix.
Are there natural alternatives to these drugs?
Calcium, vitamin D, and weight-bearing exercise help maintain bone health, but they can’t replace anabolic agents in severe osteoporosis. If your T-score is below -2.5 and you’ve had fractures, natural methods alone won’t reduce your fracture risk enough. These drugs are medically necessary - not optional.
Why does my doctor want me to get a DXA scan at 6 months?
Most drugs take a year to show big changes on a bone scan. But with teriparatide and abaloparatide, you can see early signs of improvement at 6 months. If your lumbar spine BMD didn’t rise by at least 3%, your doctor may suspect you’re not responding well - and might consider switching or adding another treatment.
Is abaloparatide worth the extra cost?
For some, yes. If you have very low hip bone density, a history of nonvertebral fractures, or can’t tolerate teriparatide’s side effects, the extra cost may be justified. For others - especially those with good insurance or access to generics - teriparatide remains the most practical first choice. It’s not about which is "better," but which fits your body and your life.
Alexander Pitt
March 18, 2026 AT 04:33Laura Gabel
March 19, 2026 AT 08:25cara s
March 20, 2026 AT 20:15Gaurav Kumar
March 22, 2026 AT 10:43Jeremy Van Veelen
March 23, 2026 AT 11:04jerome Reverdy
March 24, 2026 AT 15:57gemeika hernandez
March 26, 2026 AT 00:03Shameer Ahammad
March 26, 2026 AT 01:40Andrew Mamone
March 26, 2026 AT 17:35MALYN RICABLANCA
March 26, 2026 AT 19:52Amadi Kenneth
March 27, 2026 AT 16:08jared baker
March 28, 2026 AT 10:37