What's a "Buffer"?
A prescription buffer means having 1-2 weeks of extra medication beyond your immediate needs. This gives you time to find supply if your pharmacy has a stock-out. It's not stockpiling — you're not hoarding months of supply.
How to Build a Buffer Legally
1. Order Prescriptions Promptly
Most GP practices allow you to reorder repeat prescriptions when you have 7-10 days of supply left. If you order at the earliest opportunity each time, you'll gradually accumulate a small buffer. For example, if you order with 10 days left and collect within 2 days, you gain 8 days' overlap each month.
2. Use the 28-Day Prescription Cycle
Standard NHS prescriptions are for 28 days. Calendar months are 30-31 days. Over several months, this slight mismatch naturally creates a small buffer if you reorder consistently on the same calendar date each month.
3. Ask About Slightly Longer Prescriptions
Some GPs will issue 56-day or 84-day prescriptions for stable, long-term medications. Longer prescriptions can be helpful during shortages as they give your pharmacy more flexibility in sourcing.
4. Don't Waste Medication
Ensure you're taking your medication correctly and not missing doses. Missed doses effectively create a buffer, but they also compromise your treatment.
What NOT to Do
- Don't request multiple prescriptions — asking multiple GPs for the same medication is illegal
- Don't order from multiple pharmacies simultaneously using the same prescription
- Don't exaggerate symptoms to get extra medication
- Don't buy from unregulated sources to "top up" your supply
- Don't hoard — taking more than you need worsens shortages for others
Special Considerations for Controlled Drugs
Controlled substances (e.g., ADHD medications, some painkillers, benzodiazepines) have stricter prescribing rules:
- Usually limited to 30 days' supply per prescription
- Cannot be prescribed as repeat prescriptions — each requires a new, dated prescription
- Pharmacies may not dispense if the prescription is more than 28 days old
- Building a buffer is harder but not impossible — consistent early ordering helps
Related
Medicine Out of Stock
When your buffer runs out
Travelling With Medication
Planning for trips
Emergency Prescriptions
Last resort options
Page last updated: 7 February 2026. Data checked daily.