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

I'm standing at the medicine cabinet, holding a box that's been in here for, well, a while now.

Tiny print down the side, a few digits, some letters, then another string of characters.

And the million-pound question.

Which of these numbers is the expiry date?

Because one looks like a date, and the other sort of does too.

Hello, I'm Tomasz Schuster. I built the Mojapteczka app.

And what Iza's just described is probably the most common scene there is at a medicine cabinet.

It really is. It's that moment when the tiny letters on a box suddenly make a big difference.

Because I only want to know one thing. Has this medicine gone past its date?

The good news is, there are honestly only a handful of markings on a pack.

Once you know what they mean, you read them in a second.

Then let's start with the one that trips me up most.

I've got two strings of characters side by side. Which one's the date?

You'll find the expiry under one of three labels.

Either it says EXP, that's just short for expiry, or expiry date, or use by.

So they all mean the same thing?

Exactly the same. How long the manufacturer guarantees the unopened medicine keeps its quality.

And it's usually written as a month and a year. For instance, June 2027.

And here's my next puzzle. If it's just the month, no actual day, then when exactly does it run to?

The end of that month. So if you see June 2027, that means the 30th of June.

It covers the whole of that month.

Right. And if it were a full date, with a day?

Then it runs to exactly that date.

And one more thing. The format varies from country to country.

Sometimes the year comes first. Sometimes the months spelt out in letters.

If the order of the numbers isn't clear, safest to take the more cautious reading.

And if you're in any doubt, just ask the pharmacist.

Right. I've got the date.

But next to it, there's this second number.

Longer letters and digits.

And that's the one that really loses me.

That's the star of today's episode.

That's the batch number.

Marked with the word lot, or batch number, or just batch.

Lot? Like a job lot?

Different thing. Same word, mind you.

Here, lot, is the production batch identifier.

Every pack made in the same batch carries the same number.

And what would anyone at home want that for?

Two things. First, recalls.

When the medicines regulator suspends or pulls a medicine,

it's usually for one specific batch.

And that number tells you whether your pack is caught by the notice or not.

And the second?

Complaints and reports.

If something's wrong with the medicine, the pharmacist will ask for the batch number first.

But, and I want you to say this plainly,

that batch number has nothing to do with the expiry date.

Nothing at all.

The batch number isn't a date and tells you nothing about expiry.

Sometimes it's got digits that look like a year, but that's just coincidence.

You spot the expiry by the words EXP, or USE BY, and the month-year format.

The batch by the word LOT, OUGHT, or batch number.

That's it.

Give me a quick trick, because when I look, both of them read like a random string of characters.

The simplest tell.

A date usually has a slash or a dot between two numbers.

Month, slash, year.

The batch number is more often a longer string, letters mixed in with digits,

without that split into a month and a year.

So, a dot or a slash between two numbers, that's the hint it's a date?

In most cases, yes.

And if you're still not sure, look for the word.

EXP by the date, LOT by the batch.

The word settles it.

Right.

But I'm listening to this and thinking,

I am not going to copy these dates off every single box into any app.

I'm honestly not.

And you're right that it would be a slog,

which is exactly why you don't type the expiry dates in by hand.

In the Moya Pteczka app, you photograph the pack.

And what happens?

The app reads the name and the expiry date, among other things, off the photo.

And it checks what it read against an official medicines register.

So you're not tapping in with your finger what's already printed on the box.

And after that?

I've got the dates gathered up,

but I've still got to remember which one's running out.

No.

The app shows you that in colour.

Green, the date's still a long way off.

Orange, it's getting close.

Red, it's nearly up, or it's already gone.

Checking your dates is a glance down a list, then,

rather than pulling every box out of the cabinet.

Hang on.

If it reads the photo that nicely,

does it read that batch number too?

The LOT?

No.

And here I want to be honest.

The app doesn't read the batch number off the photo.

It concentrates on the expiry date,

because that's the one that matters for the day-to-day of keeping a cabinet in order.

Right.

That actually sounds honest,

because most things try to tell you they do everything.

I'd rather say what it doesn't do than promise too much.

The batch number's useful to you in one specific moment,

when there's a recall notice.

And at that point, you're looking at the pack, not the app.

Now the other side of it.

You said box,

but sometimes I've only got the blister strip left,

that foil with the tablets.

And that matters,

because the same details are in a few places,

but they're not all equally easy to read.

On the box,

the date's in the biggest print,

easiest to make out.

On the strip,

it might be embossed or printed by the seal,

tiny.

Sometimes you have to catch it under the light.

And I've got strips of tablets where you can't see a thing.

Hence a simple rule.

If you're throwing the box away,

first check the date's actually readable on the strip itself.

Very often it isn't.

And then you're left with tablets that are,

who knows how old.

That's one of the main reasons medicines you can't put an age to

pile up in the house.

Ah, I've got a few of those in the drawer.

Classic.

Everyone has.

But now tell me about something that,

as I found out recently,

isn't on the box at all.

Because I opened Basher's syrup

and suddenly didn't know how long I'd had it.

And this is the most important part today.

Because the expiry on the box is for the medicine sealed

in its original packaging.

Once it's opened,

things can change.

Meaning?

Some medicines have a shorter life once they're opened

than the date on the box.

The classics are eye drops,

syrups,

some of the things from the fridge.

And here's the thing.

The use within so many days of opening

isn't on the box.

It's in the leaflet,

in the section on storage.

Right.

So I've got that from the leaflet.

But there's still one thing

no leaflet will tell me.

When you opened it.

Exactly.

Only my house knows the opening date.

I opened Basher's syrup on some Wednesday

I can't even remember now.

And that's why it's worth getting into one small habit.

You open the eye drops,

or the syrup,

write down the opening date.

Could be in biro,

on the label,

or in a note against that medicine in the app.

So the app's got a place for that.

It has.

You 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 five minutes later.

And then you simply compare it

against the period from the leaflet,

instead of guessing.

And I think I've caught you being honest again.

The app won't work out for me

what the shelf life of this syrup is

once it's opened.

It won't.

And it's better it doesn't pretend to.

That post-opening period

is in the leaflet for the specific product,

not on the box,

and not in the app.

The app keeps your note,

and it shows the expiry dates in colour.

It doesn't judge whether a medicine

will still work.

Here's another one from real life.

In our house,

medicines come into the cabinet

from all over.

I buy something,

my mother-in-law Eljbieta

brings something round,

something's left over from Leon's cold.

And that's how you easily end up

with a second box of the same medicine,

often with a different batch number

and a different expiry.

The app flags that

by looking at the active ingredient,

not just the name on the box,

before you buy a third pack.

There was a whole earlier episode

on that, actually.

Two packs in the drawer.

Exactly.

Today we're closing that one off

from the other end,

what's actually printed on the pack.

Then let's do a quick recap at the end,

because I do like something concrete.

Here goes.

EXP.

Use by.

Expiry date.

That's the expiry date.

Just a month and a year means

good until the end of that month.

LOT.

Batch number.

That's the batch number.

For recalls and complaints,

it is not a date.

On the strip,

the details can be unreadable.

Copy the date off the box

before you throw it out.

The opening date

isn't on the packaging.

Write it down yourself.

And check the post-opening period

in the leaflet.

And that's it.

Reading a pack is a small skill.

But a cabinet you can trust

is built out of exactly

these little things.

The kind where you know

what you've got,

what's still in date,

and what you don't

need to buy again.

And if you'd like to get

on top of this

without copying expiry dates

off every box by hand,

that's what the

Moya Pteczka app is for.

The app is free

and works offline.

You'll find the link

in the episode description.

It's a tool for running

your medicine cabinet,

not for making medical decisions.

Those are for your GP

and your pharmacist.

One more thing before we go.

This podcast is made

with the help

of artificial intelligence.

I wrote the dialogue myself,

but the voices you're hearing

aren't ours.

They're AI-generated

synthetic voices.

We're telling you this

straight out because we think

it should be the standard

for any podcast made this way.

Full details are in the show notes

and in every episode description.

And when I'm next

standing over a box

not knowing what to do with it?

Then you'll already know.

Until next time.