Compare Fosamax vs. Prolia

Head-to-head comparisons of medication uses, side effects, ratings, and more.



Prevents bone loss. Fosamax (Alendronate) is a first-choice treatment for osteoporosis and is available as a generic, but taking it can be a hassle.Prevents bone loss. Prolia (Denosumab) is an effective and convenient treatment for osteoporosis if other options haven’t worked or aren’t appropriate for you. There’re risks of some rare side effects, so make sure you're following up with your doctor regularly.
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Reviews & ratings
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Reviews for Fosamax (Alendronate)
of people (All ages) say Fosamax (Alendronate) is worth it
say it works well
say it's a big hassle
169 reviews
Have you used Fosamax (Alendronate)?
Worth itNot sureNot worth it

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Have you used Prolia (Denosumab)?
Worth itNot sureNot worth it
Side effects

We haven’t found good data for Fosamax side effects.

FDA side effect reports for Fosamax »
  • Pain in extremity 1%
  • Hypercholesterolemia 1%
  • Ankle and leg swelling 1%
  • Ear, nose, or throat infection 1%
  • Sciatica 1%
More Prolia side effects »
How it works
Fosamax (Alendronate) is a bisphosphonate. It slows down osteoclasts, the cells that break down bone. This results in greater bone mass and lowers the possibility of fractures.Prolia (Denosumab) is a monoclonal antibody. It blocks a protein that sends signals to break down your bones, and therefore prevents bone loss.
Type of medication
Prescription only
Prescription only
Available as
  • Pill
  • Effervescent tablet
  • Liquid
  • Injection
Used for
Risk factors for serious side effects
      • Oral or dental surgery
      • Cancer
      • Poor oral hygiene
          Detailed Fosamax (Alendronate) risks & warnings »
          • Taking steroids
            • Kidney problems
            • Not taking calcium supplements
            • Taking other medicines that can lower calcium blood levels
            • History of hypoparathyroidism (low levels of parathyroid hormone)
            • Weak immune system
            • Taking medicines that block your immune system (such as transplant medications or steroids)
            • Oral or dental surgery
            • Cancer diagnosis
            • Taking steroids or chemotherapy
            • Poor oral hygiene
              Detailed Prolia (Denosumab) risks & warnings »

              Research studies with animals found harmful effects on unborn babies. It hasn’t been properly studied in humans. The benefits might outweigh the risks even if you’re pregnant. Talk with your doctor.

              Research studies with real people or animals found harmful effects on unborn babies. If you’re pregnant, the risks to your unborn baby outweigh the benefits.

              • People on Fosamax (Alendronate) have reported breakdown of the jaw bone. This is rare. This can happen if you have oral or dental surgery, or if you have poor oral hygiene. If you notice pain, swelling or an infection in your jaw, talk to your doctor right away. Also, tell your surgeon that you are taking Fosamax (Alendronate).
              No food related info.
              No pain related info.
              • Can cause skin irritation, joint pain, limb pain, and back pain.
              Upsides and benefits
              • Lowers your risk of bone fractures.
              • Available as a generic medication.
              • Available in two forms: one that can be taken once a day or another that's taken once a week.
              • Comes as a regular tablet, an oral solution, or effervescent tablets meant to be dissolved in water.
              • Prolia (Denosumab) is effective at preventing bone loss, making your bones stronger and lowering your chance of getting a fracture.
              • Only need to get an injection every 6 months, so you don’t have to remember to take something every day.
              Downsides and risks
              • You need to take it the first thing in the morning with a full glass of water.
              • Not good for people who can't sit or stand upright for at least 30 minutes in the morning.
              • The use of bisphosphonates increases your risk of other types of fractures not related to osteoporosis (called atypical fractures).
              • Can cause bad heartburn or stomach problems.
              • Approved for women only after they’ve reached menopause. Don’t use this if you’re pregnant or planning to become pregnant.
              • Can lower blood calcium levels. You might need to take calcium supplements to prevent this.
              • Not available as a generic.
              Tips from our pharmacists for people taking the medication
              • Take Fosamax (Alendronate) first thing in the morning with a full glass of water before eating or drinking anything else, including other medicines.
              • The pill must be swallowed whole.
              • Stay upright for at least 30 minutes after taking the medicine, and don't eat or drink anything except plain water during that time.
              • Make sure you take enough calcium and vitamin D to allow this medicine to work.
              • Can cause an upset stomach, joint pain, back pain, or heartburn.
              • Stop taking the medicine and let your doctor know if swallowing becomes painful, if you have chest pain, or if any of the side effects worsen.
              • If you have dental work coming up, get it done before starting this medicine since some people have experienced serious jaw problems while on Fosamax (Alendronate).
              • Remember to get your shot every 6 months. Write it down on your calendar.
              • If your doctor also told you to take calcium and vitamin D, remember to take them as well. They'll work with Prolia (Denosumab) to help protect your bones.
              • Can cause skin irritation, joint pain, limb pain, and back pain.
              • Let your doctor know if you start getting more infections.
              • Let your dentist know that you’re taking Prolia (Denosumab) since it can cause problems in the jaw bone after dental procedures.
              Learn more
              More about FosamaxSide effectsReviews & ratingsAlternativesFDA package insert
              Have you used Fosamax (Alendronate)?
              Worth itNot sureNot worth it
              More about ProliaSide effectsReviews & ratingsAlternativesFDA package insert
              Have you used Prolia (Denosumab)?
              Worth itNot sureNot worth it