Episode 7 — EXP, LOT, and the date that isn't on the box

You’re standing at the medicine cabinet, holding a box that’s been in there “a while now”. Tiny print down the side: a few digits, some letters, then another string of characters. Which one is the expiry date? And has it gone past it yet? This episode takes the tiny letters on a pack apart — Tomasz and Izabela read a box so it takes a second, not an evening.

EXP, “Use by”, “Expiry date” — they all mean the same thing: the expiry date. Most often written as a month and a year, for instance 06/2027. That means the medicine is good until the end of that month — so the thirtieth of June. If there’s a full date with a day on the pack, it runs to exactly that date. The format varies from country to country, so when the order of the numbers isn’t clear, safest to take the more cautious reading and, if in doubt, ask the pharmacist.

LOT (the batch number) is that second string, the one that trips most people up. It’s the production-batch identifier — useful for recalls (when the medicines regulator suspends a medicine, it’s usually for one specific batch) and for complaints. The key thing: the batch number is not a date and tells you nothing about expiry. You spot the date by the words “EXP” / “Use by” and the month-year format; the batch by the word “LOT” / “Batch number”. A simple trick: a date usually has a slash or a dot between two numbers — and in the end the label next to it settles which is which.

The opening date — the thing that isn’t on the pack at all. The date on the box is for the medicine sealed. Some medicines have a shorter life once opened (classically eye drops and syrups) — but you’ll find that in the leaflet, in the section on storage, not on the box. And when you opened the bottle is something no one records for you. Hence one small habit: you open the eye drops or the syrup — jot down the opening date. In biro on the label, or in a note against the medicine.

Where mojApteczka fits in — honestly, with its limits:

• Photograph the pack instead of copying dates in by hand. The app reads the name and the expiry date, among other things, off the photo, and checks what it read against an official medicines register.
• Expiry shown in colour — green (date’s a long way off), orange (getting close), red (nearly up, or already gone). Checking your dates is a glance down a list, not pulling every box out.
• Add the opening date in a note against the medicine — where you’ll always find it, rather than on a scrap of paper that goes missing.
• A second box of the same medicine — often with a different batch number and a different expiry — gets flagged by active ingredient, before you buy a third.

What the app deliberately does not do: it doesn’t read the batch number (LOT) off the photo, it doesn’t work out the post-opening shelf life for you (that’s in the leaflet for the specific product), and it doesn’t judge whether a medicine “will still work”. It’s a tool for running your home medicine cabinet, not for making medical decisions — those are for your GP and your pharmacist.

Topics:

• EXP / “Use by” / “Expiry date” — and what just a month and a year means
• LOT (the batch number): what it’s for and why it isn’t a date
• How to tell the expiry date from the batch number at a glance
• Blister strip vs box: why it’s worth copying the date off before you bin the carton
• The opening date — what isn’t on the pack, and how to handle it

Materials:

• The mojApteczka app: mojapteczka.pl — free, works offline
• Return unused or expired medicines to the pharmacy (take-back / safe disposal) — never the bin or the sink
• Contact: kontakt@mojapteczka.pl

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About AI in this episode. The dialogue was written by Tomasz Szuster. The voices you hear are AI-generated synthetic voices — not recordings of the hosts. We say this straight out, because we think it should be the standard for any podcast made this way. Full details in the show notes and in the episode outro.