What is a medical device?
The legal definition
Under the Medicines Act 1981, a medical device is defined as:
Any instrument, apparatus, implement, machine, appliance, implant, reagent for in vitro use, software, material, or other similar or related article, intended by the manufacturer to be used, alone or in combination, for human beings for one or more of the specific purposes of:
- diagnosis, prevention, monitoring, prediction, prognosis, treatment, or alleviation of disease
- diagnosis, monitoring, treatment, alleviation of, or compensation for, an injury or disability
- investigation, replacement, modification, or support of the anatomy or of a physiological process or state
- supporting or sustaining life
- control of conception
- disinfection or sterilisation of any of the above
- providing information by means of in vitro examination of specimens derived from the human body
and which does not achieve its principal intended action by pharmacological, immunological, or metabolic means — though it may be assisted in its function by such means.
Breaking the definition down
Intended purpose is what matters
The definition turns on the manufacturer's intended purpose, not how the device is actually used. A product that could theoretically diagnose disease is only a medical device if that is how the manufacturer intends it to be used and describes it.
The pharmacological exclusion
If a product works primarily through pharmacological, immunological, or metabolic means, it is a medicine — not a medical device. However, some combination products can incorporate both a device and a medicinal substance. In those cases, the regulatory pathway depends on which component provides the principal mode of action.
Software is included
The definition explicitly includes software. Whether a particular software product is a medical device depends on its intended purpose and function. See Software and SaMD for full guidance on how Medsafe approaches this.
Common examples
| Product | Typically a device? |
|---|---|
| Surgical scalpel | Yes |
| Blood pressure monitor | Yes |
| Insulin pump | Yes |
| Glucose test strips (IVD) | Yes — classified as an IVD |
| ECG analysis software | Likely yes — check SaMD guidance |
| General wellness app | Generally no |
| Antibiotic cream | No — medicine |
| Bandages and dressings | Yes |
| Dental implants | Yes |
| Contraceptive IUD | Yes — classified Class III |
Accessories
Accessories to a medical device that are specifically intended by their manufacturer to enable the device to be used as intended are generally also considered medical devices. The accessory takes its own classification — it is not automatically assigned the same class as the device it accompanies.
Borderline products
Some products sit on the boundary between a medical device and a medicine, cosmetic, or food. For borderline products, Medsafe offers a categorisation service — you can submit product details, labelling, instructions for use, and promotional materials for an advisory opinion on how the product would be regulated.
If you are unsure whether your product is a medical device, contact Medsafe's categorisation service before investing in WAND notification or technical documentation. See Useful Links for contact details.
What is not a medical device?
Some items look like medical devices but fall outside the definition. See What is not a medical device? for a full breakdown.