Bone, kidney & bladder
Bisphosphonate
Alendronate
Also known as: Fosamax
Best time
On waking, empty stomach
- 06:00–08:00
Take first thing in the morning with plain water and stay upright for 30 minutes before eating.
Strong evidence
Consistent clinical trials or official prescribing guidance support this timing.
Why this time works
Less than 1% of the dose is absorbed even under ideal conditions, and any food, coffee or calcium blocks it. The overnight fast makes morning the only reliable window. Staying upright protects the oesophagus.
Body rhythm involved
Bone breakdown peaks at night; the overnight fast maximises absorption.