Why does my generic pill look different this month?

You open a refill of something you have taken for years and the tablet is the wrong colour. Or it is oval instead of round, or the imprint is a different set of letters. Nothing about the bottle warned you. The natural reaction is to stop taking it until someone explains, and that reaction is more common than most people realise: surveys of adults over 50 have found roughly one in eight has stopped or reduced a medicine because a refill looked unfamiliar.

The usual explanation is dull, and that is good news. Your pharmacy switched generic manufacturers.

What a generic is allowed to change

A generic medicine has to match the brand on the things that determine what it does in your body — the active ingredient, its strength, the dosage form, and how it is absorbed. What it does not have to match is how it looks. In the United States, trade dress is protected, which means a generic manufacturer is in fact required to make the pill look different from the brand.

So the inactive parts are free to differ, and they are the parts you can see:

• Colour, from the dyes in the coating
• Shape and size, from the pressing dies used
• The imprint code stamped on the tablet, which is specific to the manufacturer
• Fillers and binders, which is why a different generic can sit differently with some people

Pharmacies switch suppliers for ordinary reasons — a wholesaler contract changed, one manufacturer had a shortage, another quoted better. Nobody tells the patient, because from the pharmacy's point of view nothing happened.

How to confirm it yourself

The number that settles it is the NDC, the National Drug Code, printed on the pharmacy label and on the manufacturer's packaging. It has three parts: the labeler (who made it), the product (which drug, which strength, which form), and the package size.

When a pharmacy switches generic suppliers, the first part changes and the middle part still describes the same drug and strength. That is the signature of a manufacturer change rather than a different medicine. You can look an NDC up in the FDA's National Drug Code Directory, which is public, free, and the same source the printed insert is drawn from.

When it is worth a phone call

A different-looking pill is usually a supplier change. It is worth calling your pharmacy before taking it when:

• The drug name or the strength on the label is not what you were expecting
• The label says a different medicine than the one you were prescribed
• The NDC on the bottle does not match the medicine described when you look it up
• You have had a reaction to a different generic of the same drug before — the fillers differ, and some people notice
• Nothing on the packaging matches what you were told at the counter

Pharmacists field this question constantly and would far rather answer it than have you skip doses. Asking costs a few minutes; stopping a medicine on your own can cost a great deal more.

The habit worth building

Checking a refill takes about fifteen seconds and it answers a question that would otherwise sit in the back of your mind all month. It also means that on the rare occasion something genuinely is wrong, you find out at the kitchen counter rather than a week later.