One-Month Supply Calculation
For a patient taking one capsule twice daily, a one-month supply is 60 capsules (2 capsules per day × 30 days = 60 capsules).
Rationale
When a medication is prescribed as "one capsule twice daily," the patient takes:
- 2 capsules per day (one in the morning, one in the evening)
- Over a standard 30-day month, this equals 60 capsules total
Practical Considerations
Dosing Frequency and Compliance
Research demonstrates that twice-daily dosing results in significantly lower adherence compared to once-daily regimens. Studies show compliance drops from 79% with once-daily dosing to as low as 38% with three-times-daily dosing 1. Meta-regression analysis reveals that twice-daily dosing has 14.2% worse regimen adherence and 22.9% worse timing adherence compared to once-daily dosing 2.
Supply Duration Options
While a 30-day (60 capsule) supply is standard, 90-day supplies offer substantial cost savings:
- 29% reduction in out-of-pocket costs for patients
- 18% reduction in total prescription costs
- 80% of patients achieve some cost savings with 90-day supplies 3
For this twice-daily regimen, a 90-day supply would be 180 capsules (2 capsules/day × 90 days).
Common Pitfalls to Avoid
- Don't confuse "twice daily" with "two capsules once daily" - these are different regimens with different total quantities
- Account for the full 30 days - some prescribers mistakenly calculate for 28 days or 4 weeks
- Consider requesting 90-day supplies when appropriate to reduce costs and pharmacy visits, though this requires 180 capsules for twice-daily dosing