Forteo (teriparatide)

An FDA-approved daily shot that builds bone in some people with osteoporosis who are at high risk of breaking a bone.

AI illustration of an injector pen labeled Teriparatide — AI illustration

FDA statusFDA approved

The FDA approved it as a prescription medicine for certain uses.

Proof it works in people for weak bones (osteoporosis)Strong

A big trial showed far fewer spine fractures.

Safety data in peopleWell studied

Thousands of people. Risks are on the FDA label.

These are 3 different questions. FDA status is about the law. Proof is about whether it works. Safety data is about how much we know about its risks. A lack of safety data does not mean it does not work, and "not approved" does not mean "illegal."

By the Peptide Science Desk Editorial TeamFact-checked against FDA and official sources · Oct 18, 2026Not yet reviewed by a licensed clinician. How we check facts

What is it?

Teriparatide is a peptide medicine. It is the first 34 building blocks of parathyroid hormone, a natural body signal that helps control calcium and bone. The brand is Forteo. You need a prescription.

Why do people use it?

Doctors use it for osteoporosis (weak, thin bones) in women after menopause and in men who are at high risk of breaking a bone, and for bone loss caused by steroid medicines.

Does it really work?

This one is proven. The label says that in women after menopause with osteoporosis, Forteo lowers the risk of breaking bones in the spine and other places.

Studies in people

Study	People	What they found	Limits
Randomized trial	1,637 women	New spine fractures: 5% vs 14% on placebo.	Women after menopause who already had a fracture.

We only list studies we read on PubMed or ClinicalTrials.gov. Checked October 18, 2026.

The numbers in charts

New spine fractures on bone-building shots

% of women with weak bones who got a new spine fracture, drug vs placebo

Teriparatide 20 µg (Forteo)1,637 women · about 21 months

14%

Abaloparatide (Tymlos)ACTIVE · 1,401 women in this count · 18 months

0.6%

4.2%

Different trials, different people: not a head-to-head comparison. Lower is better.

Show the numbers as a table

New spine fractures on bone-building shots: % of women with weak bones who got a new spine fracture, drug vs placebo
Trial	Drug	Placebo
Teriparatide 20 µg (Forteo) 1,637 women · about 21 months	5%	14%
Abaloparatide (Tymlos) ACTIVE · 1,401 women in this count · 18 months	0.6%	4.2%

Teriparatide numbers are from the trial paper. Abaloparatide numbers are from the Tymlos FDA label (Table 3: 690 women on the drug vs 711 on placebo). Both trials were paid for by the drug makers. Sources: Neer et al., NEJM 2001 (PMID 11346808); Tymlos FDA label, section 14, Table 3 (DailyMed); Miller et al., JAMA 2016 (ACTIVE) (PMID 27533157).

High blood calcium on bone-building shots

% of women with high blood calcium in the ACTIVE trial (2,463 women)

Abaloparatide (Tymlos)

3.4%

Teriparatide (Forteo)

6.4%

Both drugs were in the same trial, so this one is a fair side-by-side look.

Show the numbers as a table

High blood calcium on bone-building shots: % of women with high blood calcium in the ACTIVE trial (2,463 women)
Drug	High calcium
Abaloparatide (Tymlos)	3.4%
Teriparatide (Forteo)	6.4%

Paid for by Radius Health, which makes abaloparatide. Sources: Miller et al., JAMA 2016 (ACTIVE) (PMID 27533157).

More charts: Peptides by the numbers

Is it safe? Side effects

The most common side effects on the label are joint pain, pain, and feeling sick.
You may feel dizzy or your heart may race when you stand up. The label says to take the first shots where you can sit or lie down.
It caused a bone cancer (osteosarcoma) in rats. A few cases have been reported in people, but studies in people have not shown a higher risk.
It can raise calcium in the blood.

Is it legal in the US?

Yes. Forteo is FDA-approved for its labeled uses. (The FDA is the US agency that checks if medicines are safe and work.) Using it for anti-aging or sports is not an approved use.

What "not approved" does and does not mean

With a prescription, it is legal to use for the uses on its FDA label.
Doctors may also prescribe an approved drug for other uses ("off-label") when they think it is right for you. (FDA)
Copies made by a pharmacy (compounded) are not FDA approved. The FDA does not check them before they are sold. State boards of pharmacy oversee most pharmacies. (FDA)
Products sold online "for research" or "not for human use" are not the approved medicine. The FDA has warned companies that sold them to people. (FDA)

Banned in sports? Drug tests

Not named on the banned list.

Teriparatide (Forteo) is not named on WADA's 2026 list. It is an approved medicine, so the "not approved" rule (S0) does not fit. But WADA says its list is not complete. Check it on GlobalDRO.com or ask USADA.

Check work, NCAA, and military rules for Forteo

Talk to your doctor

Do not start any peptide on your own. Ask a doctor first. We never share doses or tell you where to buy. Print our doctor questions sheet.

Check any peptide in 1 secondFree FDA Status Checker: approved, being tested, or not proven.

Forteo (teriparatide)

What is it?

Why do people use it?

Does it really work?

Studies in people

The numbers in charts

New spine fractures on bone-building shots

High blood calcium on bone-building shots

Is it safe? Side effects

Is it legal in the US?

What "not approved" does and does not mean

Banned in sports? Drug tests

Talk to your doctor

More questions

Is teriparatide the same as Forteo?

Is teriparatide a bisphosphonate?

Is teriparatide a peptide?

Related peptides

Guides and tools

Sources