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Forteo: 7 things you should know

Medically reviewed by Carmen Fookes, BPharm. Last updated on Jan 3, 2023.

1. How it works

  • Forteo is a brand (trade) name for teriparatidewhich may be used for the treatment of osteoporosis.
  • Forteo (teriparatide) works by mimicking the effects of parathyroid hormone, a naturally occurring hormone in our body. This hormone regulates calcium and phosphate metabolism in our bones and kidneys.
  • Forteo is a recombinant human parathyroid hormone (1-34), also called an rhPTH(1-34).

2. Upsides

  • Forteo may be used for the treatment of osteoporosis associated with menopause, steroid use, or low hormonal levels due to gonadal failure, in people at high risk of a bone fracture.
  • Forteo is injected under the skin, but most people can be shown how to do this themselves.
  • Forteo is usually given once per day.
  • No dosage adjustment is needed in people with kidney disease and is unlikely in people with liver disease.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • Abdominal pain, constipation, depression, dyspepsia, headache, nausea, vomiting, and weight loss are some of the common side effects. Confusion, dry mouth, a metallic taste, muscle weakness, and tiredness may also occur.
  • Animal studies have shown an association between Forteo and osteosarcoma (bone cancer) in animals. It is not known if this risk extends to humans. People with Paget's disease, high blood calcium or alkaline phosphate levels, or a history of bone cancer or radiation treatment involving bones may be more at risk.
  • Forteo should not be used in children or young adults whose bones are still growing.
  • May not be suitable for people with Paget's disease, kidney stones, high blood levels of calcium or alkaline phosphatase, overactive parathyroid glands, bone cancer, or radiation treatment involving the bones.
  • There are no controlled studies in pregnant women to determine the harms of taking Forteo during pregnancy but animal studies have shown increased skeletal deviations and variations at 6 times the human dose. Avoid in pregnancy. Encourage women of childbearing potential to use effective contraceptive during therapy while being treated with Forteo.
  • May cause dizziness or lightheadedness and affect your ability to drive or perform hazardous tasks.
  • Administered by injection under the skin (subcutaneously).
  • Forteo needs to be kept in the refrigerator when not in use.
  • May interact with some medicines, such as digoxin.
  • Use beyond two years has not been evaluated and is not recommended.
  • There is currently no generic form of Forteo available in the United States.

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

4. Bottom Line

Forteo mimics the action of parathyroid hormone to regulate calcium and phosphate metabolism and is given to people with osteoporosis at high risk of fractures. It is injected under the skin once a day but most people can be taught how to self-administer it. Proper needle disposal regulations should always be followed.

5. Tips

  • Forteo is injected under the skin and most people can be successfully taught how to self-administer these injections. Do not self-administer if you do not fully understand how to do it. Always dispose of used needles and syringes in a puncture-proof needle-disposal container. Follow your state or local laws about needle disposal.
  • Forteo can make you feel dizzy, so make sure you are sitting down somewhere before injecting it. You may also like to lie down for a short while afterward. Forteo may also affect your ability to drive or operate machinery. Do not perform these tasks if Forteo affects you in this way.
  • Animal studies have shown an association between Forteo and osteosarcoma (bone cancer) in animals. It is not known if this risk extends to humans. People with Paget's disease, high blood calcium or alkaline phosphate levels, or a history of bone cancer or radiation treatment involving bones may be more at risk. You may be asked to provide your name to a registry for monitoring.
  • Forteo is usually administered once a day, but administer it as your doctor has instructed you to. Give it at the same time of day. Use a different place on your thigh or abdominal wall each time you inject yourself, do not inject the same place two days in a row. Only use the injection pen that is provided with Forteo, do not transfer to another device. The pen contains 28 injections and you should throw it away after you have used it 28 times, even if there is some left in the device. Do not share your injection with anyone.
  • Do not use the injection if it looks cloudy, has particles in it, or has changed color. Forteo should be clear and colorless.
  • Forteo is given as part of a treatment program for osteoporosis that includes diet changes, exercise, vitamin and mineral supplements, and lifestyle measures. Follow your doctor's advice.
  • Keep Forteo in the refrigerator when not in use. Only take it out long enough to use it. If Forteo inadvertently freezes, throw that injection away.
  • If you forget to give yourself a dose, and it is still the same day, administer that dose. However, if it is the next day, do not give two doses in one day.
  • Call your doctor and ask for his/her advice if you feel like you might faint, have a rapid or fluttering heartbeat, or vomiting.
  • Seek emergency medical attention if you have any signs of an allergic reaction, such as swelling of your face or throat, hives, or difficulty breathing.
  • Do not smoke and limit your alcohol intake. Smoking and excessive drinking can reduce bone mineral density and increase the risk of fractures.
  • It is unknown if Forteo harms an unborn baby. Do not take Forteo if you are pregnant or breastfeeding and talk to your doctor immediately if you inadvertently become pregnant while taking Forteo.

6. Response and effectiveness

  • Once-daily administration of Forteo stimulates new bone formation on bone surfaces by stimulating osteoblasts (these are cells that lay down new bone) over osteoclasts (these are cells that break down bone).
  • Within 20 minutes of administration of Forteo, serum calcium levels are transiently increased, beginning 2 hours after dosing and reaching a maximum peak 4-6 hours after dosing. Serum calcium levels return to baseline 16 to 24 hours after a dose. Sustained high calcium levels are not observed.
  • Forteo reduced the risk of new vertebral fractures by 9.3% in postmenopausal women with osteoporosis after 20 months when combined with calcium and vitamin D. The risk of nonvertebral fractures was reduced by 2.9%. Significant increases in BMD were reported after 3 months of treatment.

7. Interactions

Medicines that interact with Forteo may either decrease its effect, affect how long it works, increase side effects, or have less of an effect when taken with Forteo. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

Common medications that may interact with Forteo include:

  • calcipotriene
  • calcitriol
  • diuretics, such as furosemide or hydrochlorothiazide
  • digoxin.

People taking Forteo should not drink alcohol or smoke cigarettes. Smoking can reduce your bone mineral density, making fractures more likely.

Note that this list is not all-inclusive and includes only common medications that may interact with Forteo, You should refer to the prescribing information for Forteo for a complete list of interactions.


Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Forteo only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Copyright 1996-2023 Revision date: January 3, 2023.