Alendronate: uses, side effects & brands

Written & medically reviewed by Dr. Sanjay Anbu, MBBS · Last reviewed 5 November 2026

Alendronate is a weekly bisphosphonate tablet for osteoporosis. It belongs to the Bone / osteoporosis medicine group. These strengthen bone and reduce fracture risk in osteoporosis.

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Drug type — dosing is set by your doctor

Measure	Range
Drug class	Bone / osteoporosis medicine
Type	Prescription
Dose	Individual — ask your doctor or pharmacist

What it is used for

Osteoporosis after menopause
Osteoporosis in men
Bone loss from long-term steroid tablets
Paget's disease of bone

Common brand names

India: Osteofos, Gemfos, Restofos
Worldwide: Fosamax

Common side effects

Heartburn or indigestion
Stomach pain
Bone, joint or muscle pain
Constipation or diarrhoea

Before taking it — precautions

Take exactly as the label says: on an empty stomach with a full glass of plain water, stay upright, and wait before eating or other medicines
See a dentist before starting and keep up dental care; tell your dentist you take it
Tell your doctor about kidney disease, low calcium, or swallowing or food-pipe problems

When to see a doctor urgently

Pain or difficulty swallowing, new or worse heartburn, or chest pain (urgent)
Jaw pain, loose teeth or a mouth sore that will not heal
New pain in the thigh, hip or groin

Not a prescription — no dose shown. The right dose of alendronate depends on age, weight, kidney/liver function and the condition, so MedDroid does not show a dose here. Always get your dose from a doctor or pharmacist and the leaflet inside the pack. General educational information only.

Frequently asked questions

Why is it taken only once a week?

The weekly form lasts in the bone, so it is taken once a WEEK on the same day — not daily — unless your doctor prescribed a daily form.

Do I need calcium and vitamin D too?

Usually yes, if your diet is low — but take calcium at a different time from alendronate.

How long will I take it?

Your doctor reviews it after some years and may advise a break depending on your fracture risk.

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Sources & further reading

Reviewed by Dr. Sanjay Anbu, MBBS. MedDroid is an AI medical assistant and can make mistakes. It provides general health information, not a diagnosis or medical advice — always consult a qualified clinician. In an emergency, contact your local emergency number immediately.