top of page
Various medications and vitamins, a pill

Steps for strong bones:

6. Medications

Understanding how osteoporosis medications work

It is very helpful to understand basic bone physiology to fully understand how medications for osteoporosis work. As you learned in section 1, osteoporosis happens due to an imbalance of bone removing cells (osteoclasts) and bone building cells (osteoblasts) which results in decreasing bone density and decreasing bone quality. If you did not read this section, go back and read it now. There are several classes of medications used to treat osteoporosis, and they are taken a multitude of different ways (daily pill, weekly pill, monthly pill, daily injection, monthly injection, injection every 6 months, or infusion every year).

There are several considerations for treatment. Most importantly the risk of a fracture imminently and long term must be considered. There is no cure for osteoporosis. Someone with osteoporosis will have to be monitored for the rest of their lives. A long term plan should be considered. Different medications provide varying degrees of fracture protection. Other determinants of deciding which medication to proceed with include patient preferences, cost, insurance preferences, etc.

Osteoporosis medications are generally split up into 2 groups based on how they work. The two groups are anabolic medications and anti-resorptive medications. Both groups of medications significantly reduce the risk of fractures.


Anabolic medications work by stimulating bone building cells to grow new bone. These anabolic medications are the only medications that improve bone quality by increasing the bone microarchitecture. Anabolic medications also provide the best and fastest fracture protection.

Anti-resorptive medications work by decreasing bone loss by slowing down the bone removing osteoclasts. 

Concerns about side effects:

All medications can potentially cause side effects. People are often times in denial about osteoporosis, again, because osteoporosis does not cause any symptoms (until you break a bone). Osteoporotic broken bones are responsible for significant loss of independence, cost, pain, and death. While considering treatments for osteoporosis, benefits of treatment need to be carefully weight against the risks. If treatment is recommended, the risk of a serious adverse effect is very small compared to the risk of a fracture going untreated.

Anabolic Medications

Parathyroid Hormone analogues

Medications in this class include: Tymlos (abaloparatide) and Forteo (teriparatide)

  • These medications improve bone density and quality

  • Associated with the best protection against fractures

  • Daily injection, usually for up to 2 years, followed by anti-resorptive medication

  • Adverse effects: transiently decreased blood pressure with changes in position, dizziness, body aches, bone pain, abdominal pain, high blood calcium levels, increased urine calcium levels, and headaches.

  • Clinical studies involving rats showed increased evidence of bone cancer (osteosarcoma), but this has not been demonstrated in humans


​Medication in this medication class: Evenity (romosozumab)

  • This medication has anabolic and anti-resorptive effect. It is the only medication that has a dual action. Provides very fast protection from fractures and bone building

  • Injection once per month for 1 year in office, followed by anti-resorptive medication

  • Possible side effects: injection site problem, low blood calcium, allergic reaction, achy joints, osteonecrosis of jaw, atypical femur fractures. One of two clinical trials showed slight increased incidence of cardiovascular events (strokes and heart attacks) in patients receiving Evenity. Although this was not seen in the other 2 clinical trials, Evenity is not recommended in patients who have had a stroke or a heart attack with the last year or in someone who is high risk for having strokes or heart attacks

Anti-resorptive Meds


Oral medications in this class: Fosamax (alendronate), Boniva (ibandronate), and Actonel (risedronate) – pills taken weekly or monthly

  • Work for a very long time, even after medications are stopped

  • Holiday considered after 5 years

  • Possible side effects – low blood calcium, abdominal pain, heartburn, nausea, difficulty swallowing, bone or joint pain, constipation, diarrhea, atypical femur fractures (very rare), osteonecrosis of the jaw (very rare)

Intravenous medications in this drug class: Reclast (zoledronic acid) IV infusion, once per year

  • Holiday considered after 3 years

  • Possible side effects: low back and joint pain, nausea, fever, fatigue, anemia, vomiting, constipation, diarrhea, dizziness, headache, eye pain, low blood calcium level, osteonecrosis of jaw (very rare), and atypical femur fractures (very rare)

Rankl inhibitor

Medication in this medication class: Prolia (denosumab)

  • given as an injection in the arm in the office, twice per year

  • Drug holiday not recommended – bone loss and increase spine fracture risk occurs when stopped abruptly, although if this medication needs to be stopped, another medication can be started in its place to prevent this

  • Possible side effects: injection site problems, low blood calcium, rash, achy joints, decreased immune system, elevations in cholesterol, osteonecrosis of the jaw (very rare), atypical femur fractures (very rare).

Selective estrogen receptor modulator (serm)

​Medication in this class of medication: Evista (raloxifene)

  • Mimics effect of estrogen on bone and blocks estrogen in breast tissue, providing protection against breast cancer

  • For women only

  • Daily Pill

  • Possible adverse effects: hot flashes, flu syndrome, cramps/muscle spasms, arthralgias, infection, insomnia, vomiting, blood clots (1-2%)

bottom of page