Rx only (prescription device)
The regulation’s wording:
“The label of a prescription device bears “the symbol statement ‘Rx only’ or ‘℞ only’ or the statement ‘Caution: Federal law restricts this device to sale by or on the order of a ___’”.”
21 CFR 801.109(b)(1) · US federal regulation 21 CFR 801.109, not ISO 15223-1
What it means for you
In the United States the device may only be sold to, or on the order of, a licensed practitioner — a physician, dentist or other prescriber. It is a US sales restriction, which is why it also shows up on devices sold elsewhere.
Whether a device is right for you is a question for your pharmacist, nurse or doctor.
- What it looks like
- The text “Rx only” or “℞ only”, often without a box.
- Where you see it
- US labels of hearing aids sold by prescription, contact lenses, needles, catheters and many professional devices.
- Other names
- ℞ only; prescription only; Caution: Federal law restricts this device
What it does not tell you
Outside the US it has no legal effect of its own; local rules decide whether you need a prescription. It says nothing about how risky the device is for you.
More symbols in “Letters”
Sources
Taken from 2 publishers’ public documents. Each was fetched and read on the date shown:
- eCFR (US Office of the Federal Register): 21 CFR 801.109 — Prescription devices — § 801.109(b)(1): the label bears “The symbol statement ‘Rx only’ or ‘℞ only’ or the statement ‘Caution: Federal law restricts this device to sale by or on the order of a ___’”, the blank filled with physician, dentist, veterinarian or another licensed practitioner. Checked 2026-09-25.
- BÜHLMANN Laboratories: Symbol glossary, version 03 (release date 2025-02-04) — Lists “Restricted devices in US — Indicates a medical device that can only be sold, distributed or used upon the order of an authorized healthcare provider in the USA. 21 CFR 801.109(b)(1)”. Checked 2026-09-25.
Plain-language parts are in our own words; quotations are the sources’ wording.