Side effects are real, and dismissing them does not help anyone. But context matters enormously. The side effects associated with osteoporosis medications, even the rare ones, need to be weighed against the consequences of untreated osteoporosis: vertebral fractures, hip fractures, loss of independence, and in some cases shortened life expectancy. That is not a reason to accept intolerable side effects. It is a reason to find ways to manage the tolerable ones.

CALLOUT: The most common reason women stop osteoporosis medication is not severe side effects. It’s mild, manageable symptoms that were never properly explained or supported. Understanding what to expect, and what to do about it, makes a significant difference to whether treatment succeeds.

Digestive side effects from oral bisphosphonates

Heartburn, indigestion, nausea, and stomach discomfort are the most commonly reported side effects of oral bisphosphonates. They occur because the medication can irritate the lining of the oesophagus and stomach if not taken correctly.

Practical strategies:

  • Take the tablet with a full glass of plain water. Not a small sip
  • Stay strictly upright for 30 minutes. Do not sit on the sofa or return to bed
  • Do not take the medication if you have significant reflux or oesophageal symptoms on that morning. Wait until the next scheduled dose
  • If symptoms persist, speak to your doctor about switching to risedronate (often better tolerated) or to an annual infusion instead

CALLOUT: Switching from alendronate to risedronate, or from an oral tablet to an annual zoledronic acid infusion, is a straightforward clinical decision. If your digestive side effects are making it difficult to stay on your medication, raise it. There are alternatives.

Flu-like symptoms after zoledronic acid infusion

An acute phase reaction such as fever, muscle aches, fatigue, and headache in the 24 to 72 hours after an infusion occurs in approximately 30 percent of women after their first zoledronic acid infusion. It is significantly less common with subsequent infusions.

  • Take paracetamol before and after the infusion to reduce severity
  • Stay well hydrated on the day of the infusion and the following day
  • Rest if needed. Symptoms typically resolve within two to three days
  • This reaction does not indicate an allergy and does not mean the medication is harmful

QUOTE: "The flu-like reaction after a first infusion is uncomfortable but temporary. Most women who experience it find subsequent infusions much easier. It is not a reason to stop a medication that may be preventing a hip fracture."

Hot flushes and leg cramps from raloxifene

Raloxifene can worsen hot flushes, particularly in women who are recently menopausal. It can also cause leg cramps, especially at night. These side effects are most pronounced in the first few months and often improve over time.

If hot flushes are significantly affecting sleep or quality of life, speak to your doctor. Raloxifene may not be the right choice if menopausal symptoms are already a significant burden.

Managing injection site reactions

Prolia, romosozumab, teriparatide, and abaloparatide are all given by injection. Injection site reactions such as redness, bruising, swelling, or discomfort at the site are common and generally mild.

  • Rotating injection sites reduces localised irritation
  • Allowing the medication to reach room temperature before injection reduces discomfort for the pen-device medications
  • Applying gentle pressure after injection helps

CALLOUT: If you are self-administering teriparatide or abaloparatide and finding it difficult or distressing, ask your doctor or nurse to review your technique. Small adjustments to timing, angle, or site rotation often make a significant difference.

Osteonecrosis of the jaw (ONJ) - what the evidence actually says

ONJ is a condition in which bone in the jaw fails to heal properly, typically following a dental procedure such as a tooth extraction or implant. It is the side effect that causes the most anxiety among women on osteoporosis treatment and the one most frequently misrepresented online.

This section is based on the 2026 Healthy Bones Australia consensus statement on medication-related osteonecrosis of the jaw (MRONJ).

CALLOUT: Most of the fear around ONJ comes from cancer treatment data, not osteoporosis data. Patients with cancer receive anti-resorptive medications at doses roughly 100 times higher and far more frequently than those used for osteoporosis. The risks are not comparable, and conflating them has contributed significantly to treatment abandonment.

What the actual risk is at osteoporosis doses

Based on current evidence, the risk of ONJ at osteoporosis doses is:

  • Bisphosphonates: approximately 0.02–0.04% - up to 4 in every 10,000 patients
  • Denosumab: approximately 0.04–0.3% - up to 3 in every 1,000 patients, though some of this may relate to prior bisphosphonate use in those groups

For context - bisphosphonates and denosumab reduce fracture risk by up to 70%. The risk of a serious hip fracture, and the cascade of consequences that can follow, is substantially greater than the risk of ONJ at osteoporosis doses. For most women, the benefit of treatment far outweighs this risk.

Risk does increase with longer duration of treatment. For bisphosphonates, the risk increases appreciably after four years of use. For denosumab, risk also increases with long-term therapy. Other factors that raise risk include poor oral hygiene, active dental infections, poorly controlled diabetes, smoking, and certain medications used in cancer treatment.

CALLOUT: ONJ can also occur spontaneously in people who have never taken osteoporosis medication, though rarely. It is not exclusively caused by these medications, and its development involves multiple contributing factors beyond the drug itself.

What reduces the risk

The most evidence-based protective measures are straightforward:

  • Brush teeth for at least two minutes twice daily with fluoridated toothpaste
  • Clean between teeth daily with floss or interdental brushes
  • Attend regular professional dental examinations
  • Seek prompt treatment of any dental symptoms. Do not let infections linger
  • Ensure dentures fit well
  • Stop smoking

QUOTE: "Good oral hygiene and regular dental care are the most powerful tools available to reduce ONJ risk. They are also entirely within your control."

Before starting treatment, a dental assessment is recommended where possible to identify and treat any existing dental disease. However, in women with a recent fragility fracture or a high imminent fracture risk, waiting for dental clearance should not delay starting treatment. Your doctor and dentist can work together to manage timing appropriately.

If you need a dental procedure while on treatment

This is the area that causes the most confusion and where the most outdated advice still circulates.

If you need a dental procedure while on a bisphosphonate or denosumab, inform both your doctor and your dentist. A risk assessment based on your specific situation will determine what precautions are appropriate.

The current Australian guidelines are clear on several points:

  • Patients at low risk of ONJ can proceed with routine extractions and implants safely
  • Patients at higher risk should be referred to a specialist
  • Good oral hygiene and minimising active dental infection before a procedure are the key protective measures
  • Antibacterial mouthwash before and after extraction is recommended in intermediate-risk cases

CALLOUT: There is no evidence that stopping your osteoporosis medication before a dental procedure reduces the risk of ONJ. Current Australian guidelines advise against stopping treatment without discussion with your doctor. For bisphosphonates, a short break may be considered safe in low-fracture-risk patients but for denosumab, stopping or delaying a dose is not safe and carries a real risk of rapid bone loss and fracture. Never make this decision independently.

The side effects that require immediate attention

Most side effects from osteoporosis medications are manageable. A small number require prompt medical attention:

  • Difficulty swallowing, chest pain, or severe stomach pain when taking an oral bisphosphonate. Stop and contact your doctor
  • Jaw pain, swelling, or a non-healing sore in the mouth. Contact your doctor and dentist promptly
  • Thigh or groin pain during bisphosphonate treatment. Report to your doctor to rule out an atypical femoral fracture
  • Muscle cramps, tingling in hands or feet, or irregular heartbeat. These can indicate low calcium levels; contact your doctor

CALLOUT: None of these symptoms are common. But knowing what to watch for and acting promptly if they occur is part of being an informed patient. Lenari's medication guide lists the specific symptoms to watch for with each individual medication.

The concern most women don't voice

Many women stop their medication not because of physical side effects but because of anxiety about rare complications read about online, about long-term consequences they cannot fully evaluate, or about a general discomfort with taking medication indefinitely.

These concerns are legitimate and deserve to be discussed with your doctor, not dismissed, and not managed by quietly stopping treatment.

QUOTE: "If something you have read about your medication is worrying you, bring it to your appointment. A good doctor will not brush it off. They will help you understand the actual risk in the context of your actual situation."

When a side effect means reconsidering treatment

Not every side effect is manageable, and not every medication is the right fit for every woman. If a side effect is genuinely disrupting your quality of life, that is a conversation worth having with your doctor. There are multiple medication options for osteoporosis. If one is not working for you, there are others. The goal is to find a treatment you can sustain because a medication taken consistently for three years does more for your bones than one abandoned after three months.

CALLOUT: Lenari's medication guide covers the specific side effects and warning signs for each individual medication. If something you are experiencing is not listed there, or if you are unsure whether what you are feeling is a side effect, speak to your doctor or pharmacist. [Go to medication guide →]