Can a medical device label or IFU have a correctly spelled wrong word?

Yes. Device labeling, including instructions for use (IFUs), is covered by the FDA's device labeling rules in 21 CFR Part 801, and the regulation says directions for use can be inadequate because of incorrect specification of important details. An IFU is long, step-by-step text, so one correctly spelled wrong word can change what the user does, and spellcheck passes it.

ContextRx studies drug labels, not device labels. The same read for meaning applies.

This page is general information, not legal or regulatory advice.

What rules apply

The FDA's device labeling overview lists general device labeling at 21 CFR Part 801, with related rules elsewhere, such as symbols in labeling at 21 CFR 801.15. It also notes that the FD&C Act's definition of labeling covers written, printed or graphic matter accompanying a device, and that this extends to items such as instruction books and direction sheets.

21 CFR 801.5 defines adequate directions for use as directions that let a layperson use a device safely and for the purposes for which it is intended. It says directions may be inadequate because of omission, in whole or in part, or incorrect specification of things such as the intended uses, quantity of dose, frequency, duration, time of application, route or method of application, and preparation for use.

Why IFUs attract wrong words

Our view: an IFU is a sequence. Each step depends on the one before, the text is often translated, and warnings sit between steps. A real word in the wrong spot doesn't look like an error when you skim the page.

Made-up example: a step that should say "oral" (by mouth) prints "aural" (by ear). The step still reads as a normal instruction, and the user may follow it.

Why spellcheck misses it

Both words are real and spelled correctly, so spellcheck passes them. A layout or format check passes them too.

What to check next

Practice advice:

• Proofread the IFU by doing the steps in order, with the device or a mock-up in hand.
• Read each step for what the user would physically do.
• Read route, method, timing and quantity words aloud.
• Check translated IFUs with a fluent reader for meaning, not only for completeness.
• For drug IFUs and patient labeling, see Medication Guide and IFU errors.

This is our reading of public guidance, not legal or regulatory advice.

Sources

• eCFR: 21 CFR Part 801
• eCFR: 21 CFR 801.5
• FDA: Device Labeling

Last reviewed: October 18, 2026

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What FDA rules cover medical device labeling?

General device labeling rules are in 21 CFR Part 801, including the definition of adequate directions for use in 21 CFR 801.5.

Can a device IFU have a correctly spelled wrong word?

Yes. Spellcheck passes it the same way it does on drug labels.

Does an incorrect word make device directions inadequate?

21 CFR 801.5 says directions for use may be inadequate because of omission or incorrect specification of details such as dose, frequency, route or method. Whether a given word does that is a regulatory question.

Is device labeling review different from drug labeling review?

The rules differ, but in our view the meaning check is the same: read each instruction for what the user would do.

Does ContextRx study device labels?

No. ContextRx cases come from FDA drug labels; the review habit carries over.