Tymlos (abaloparatide)
An FDA-approved daily shot for osteoporosis in people at high risk of breaking a bone.

The FDA approved it as a prescription medicine for certain uses.
A big trial showed fewer new fractures.
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 · Not yet reviewed by a licensed clinician. How we check facts
What is it?
Abaloparatide is a lab-made peptide with 34 building blocks. It is a copy-like version of a body signal called PTHrP, which works on bone. The brand is Tymlos. You need a prescription.
Why do people use it?
Doctors use it to treat osteoporosis (weak, thin bones) in women after menopause, and to build bone in men with osteoporosis, when they are at high risk of breaking a bone.
Does it really work?
This one is proven. The label says that in women after menopause with osteoporosis, Tymlos lowers the risk of breaking bones in the spine and other places. It was first FDA-approved in 2017.
Studies in people
| Study | People | What they found | Limits |
|---|---|---|---|
| Randomized trial (ACTIVE) | 2,463 women | Fewer new spine and other fractures than placebo over 18 months. | Women after menopause. |
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
Abaloparatide (Tymlos)ACTIVE · 1,401 women in this count · 18 months
Different trials, different people: not a head-to-head comparison. Lower is better.
Show the numbers as a table
| 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% |
High blood calcium on bone-building shots
% of women with high blood calcium in the ACTIVE trial (2,463 women)
Abaloparatide (Tymlos)
Teriparatide (Forteo)
Both drugs were in the same trial, so this one is a fair side-by-side look.
Show the numbers as a table
| Drug | High calcium |
|---|---|
| Abaloparatide (Tymlos) | 3.4% |
| Teriparatide (Forteo) | 6.4% |
Is it safe? Side effects
- Common side effects on the label include extra calcium in the urine, dizziness, feeling sick, headache, a racing or pounding heart, feeling tired, and upper belly pain.
- You may feel dizzy when you stand up. The label says to sit or lie down if this happens.
- The label warns about a possible risk of a bone cancer called osteosarcoma.
Is it legal in the US?
Yes. Tymlos is FDA-approved for its labeled uses. (The FDA is the US agency that checks if medicines are safe and work.)
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.
Abaloparatide (Tymlos) 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.
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.
More questions
Is abaloparatide the same as teriparatide?
No. Both are bone-building shots related to parathyroid hormone, but they are different molecules. In one trial, high blood calcium happened less often with abaloparatide (3.4%) than with teriparatide (6.4%).
Is abaloparatide a bisphosphonate?
No. It helps build bone instead of only slowing bone loss.
Is abaloparatide a peptide?
Yes.
Related peptides
Guides and tools
- Peptides for perimenopause and menopause: do any really help?Guide
- Peptides for osteoporosis and bone density: what works?Guide
- Drug test & sports ban checkerTool
- Compare Tymlos with another peptideTool
- Is my peptide source legit?Tool
- FDA warning letters trackerTool