Question About Prescription Due Date After Filling A 28-Day Supply
In our latest question and answer, the pharmacist discusses when a prescription refill is due after filling a 28-day supply.
I recently had a change to my prescription regarding how many days the supply is and so on. I had my script filled on 11/18/2022. My script used to be a 30-day supply but now is a 28-day supply. It is an opiate for chronic pain. Do I call it in on 12/14/2022? They say 2 days before it is due, if it is 28 days, that would be 12/16/2022. I want to make sure I’m addressing this way ahead of time. Thank you very much.
Nov 29, 2022- Your prescription due date is the first day you'll run out of medication if you take it as prescribed.
- Your pharmacy may allow you to fill a few days early from your due date, but policies vary so ask your specific pharmacy when you can refill.
- Different rules apply depending on the type of medication and your state's laws, so it's important to confirm fill dates directly with your pharmacy.
Answer
You're spot on with the date calculation you wrote in your question.
If you filled a 28-day supply of your prescription on 11/18/2022, you are 'due' for your next fill on 12/16/2022. Since your pharmacy has indicated that you can fill 2 days early from your 'due date', that would be 12/14/2022.
Prescription 'Due' Dates
There is often a lot of confusion surrounding prescription due dates, and when something can be filled. This generally is more of a problem with controlled substances due to ambiguity with federal and state laws, as well as individual pharmacy policies.
This is a topic we have written about several times in the past (here is a description of how your pharmacist calculates day supply and another example of a specific situation regarding controlled substances).
I think the easiest way to describe when you are legally 'due' for a prescription refill is that it is the first day in which you will not have a dose of medication to take.
For example, if you received a 7-day supply of medication on 11/7/2022, a Monday, you are 'due' for a refill on 11/14/2022, the next Monday, as that would be the first day in which you have no medication left to take.
Now, you may be able to fill your medication a little early from the actual 'due' date, but this will vary on several different factors. I always highly recommend talking directly to your pharmacy about when you can refill your medication.
Due Date After A 28-Day Supply Fill
In your example, you filled a 28-day supply prescription on 11/18/2022. The first day you would be without medication (assuming you took it consistently), would be 12/16/2022. That is your 'due' date.
In the calendar below, I list off the days (I am assuming one dose per day, but the concept is applicable regardless of how many doses you take per day) showing the due date of 12/16/2022.
If your pharmacy said they will fill it two days early, as you stated, that would be 12/14/2022.
Final Words
I really try to emphasize with these types of questions the importance of talking to your pharmacy.
There are a lot of factors that can influence prescription fill dates.
As one example, in New York State, the law states you can fill a controlled substance as long as you have no more than a 7-day supply on hand, but your prior fill history, and the policies of your prescriber and pharmacy, can alter the day you can actually fill your medication.
I hope you found this helpful! Please feel free to write back out anytime.
Glossary — Terms in This Answer
- Controlled substances
- Medications regulated by federal and state law due to their potential for abuse or dependency, such as certain pain relievers or sedatives.
- Day supply
- The number of days a prescription is expected to last based on the dosage and frequency of medication doses.
- Due date
- The first day you will run out of medication and are legally allowed to refill your prescription.
- Refill
- Getting a new supply of medication from the pharmacy when your current supply is running low.
- Dose
- A single measured amount of medication taken at one time.
- Prescription
- A written order from a doctor that authorizes a pharmacy to dispense a specific medication to a patient.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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