What Is Forteo and How Does It Treat Osteoporosis?

Written by WebMD Editorial Contributor
Medically Reviewed by Zilpah Sheikh, MD on July 16, 2025
4 min read

Teriparatide (Forteo) is an osteoporosis medicine approved by the FDA that rebuilds bone. (Bonsity is another FDA-approved version of teriparatide.) Teriparatide doesn't cure osteoporosis. It promotes the growth of new bone and makes existing bone stronger and more dense. And it reduces spine fractures in women with known osteoporosis. Research shows teriparatide may also reduce hip fractures.

Other types of osteoporosis medications improve bone density by slowing down bone resorption, or breakdown of bone.

Teriparatide is a man-made version of the human parathyroid hormone, which helps to regulate calciummetabolism in your body.

The parathyroid glands produce this hormone, which helps to control levels of calcium, phosphorous, and vitamin D in your blood. By acting like natural parathyroid hormone, Forteo shots affect minerals and vitamins that help build bone.

You inject teriparatide under your skin. The medicine comes in a prefilled pen device that you use to inject into your thigh or below your belly button. The prefilled device gives 28 daily injections. 

Tips For Use

1. It's best to get the shot at the same time every day, so you're less likely to forget a dose. 

2. Instructions for injecting yourself are included with the medicine. But you can also ask your pharmacist or doctor to show you how to do it. 

3. Rotate the areas where you get your shots to keep your skin from getting irritated or thickened over time.

4. If you get dizzy while injecting yourself, keep a chair nearby.

5. New needle tips are added to the pen device for each injection. Needles are sold apart from the pen device. 

6. Ask your pharmacist for a sharps container for throwing away the used needles.

7. Keep your Forteo pen device refrigerated. Do not put it in the freezer.

Forteo is used to treat:

  • Postmenopausal women with osteoporosis who have a high risk of fractures
  • Men and women with osteoporosis due to the use of steroid drugs who have a high risk of fractures
  • Men with osteoporosis who have a high risk of fractures

You're at high risk of fractures if you have:

  • A history of fractures due to osteoporosis 
  • Multiple risk factors for fractures
  • Not responded to, or are intolerant of, other osteoporosis treatments

Doctors don't prescribe Forteo to prevent osteoporosis or to treat mild cases.

Can Forteo be taken with other osteoporosis medications?

If you have serious osteoporosis, your doctor may prescribe both Forteo shots and another type of osteoporosis medication, such as denosumab (Jubbonti, Prolia) or zoledronic acid (Reclast). You can take Forteo by itself if you’re not able to take zoledronic acid or other osteoporosis medications that are bisphosphonates, such as alendronate (Binosto, Fosamax), ibandronate (Boniva), and risedronate (Actonel, Atelvia).

You can also take Forteo with calcium and vitamin D supplements, if your doctor prescribes them.

How long should you take Forteo?

Because scientists haven't yet established its long-term safety, this drug is FDA-approved only for 24 months of use. 

Forteo's side effects may include:

You might also have other side effects. Tell your doctor if you think you're having side effects.

 

The average cost of a Forteo pen device is about $1,000 before insurance. One pen device provides 28 doses. How much you pay for a medicine depends on several things:

  • Prices that pharmacies charge
  • Your insurance coverage and copay
  • How much medicine your doctor prescribed (Generally, 90-day supplies may be cost effective.)

To save money on medications, compare prices at different pharmacies. Also look for patient cost savings programs online.

Teriparatide (Bonsity, Forteo) is an osteoporosis treatment that builds bone and reduces fractures in the spine and hip. You take it by injection using a prefilled pen device. This drug is meant to be used only by men or postmenopausal women who have osteoporosis and a high risk of fractures. You can use it for up to two years.

How effective is Forteo for treating osteoporosis?

Forteo has been shown to reduce the risk of fractures in men and postmenopausal women. Studies also show it reduces the risk of fractures in people who have osteoporosis after taking steroids. And a recent study shows that Forteo shots cut the risk of hip fractures in half in those with osteoporosis.

Who is eligible to take Forteo for osteoporosis treatment?

Forteo should be used only in men or postmenopausal women who have osteoporosis and have a high risk of fractures. Forteo is not prescribed to women who have not yet gone through menopause and could become pregnant or breastfeed.