What is a medical device?
Regulatory basis - This page is based on Article 2(1) of Regulation (EU) 2017/745 (MDR). The definition is central to determining whether your product requires MDR compliance.
Disclaimer - This site provides general information only and does not constitute legal or regulatory advice. Always consult the official regulation text and, where appropriate, a qualified regulatory professional.
The legal definition
Under Article 2(1) of the MDR, a medical device is any instrument, apparatus, appliance, software, implant, reagent, material, or other article that:
- Is intended by the manufacturer to be used for human beings, and
- Is intended for one or more specific medical purposes, and
- Does not achieve its principal intended action by pharmacological, immunological, or metabolic means (though it may be assisted by such means).
The key medical purposes covered are:
| Purpose category | Examples |
|---|---|
| Diagnosis, prevention, monitoring, prediction, prognosis, treatment or alleviation of disease | Glucose monitors, stethoscopes, MRI machines |
| Diagnosis, monitoring, treatment, alleviation of, or compensation for, an injury or disability | Orthopaedic implants, hearing aids, wheelchairs |
| Investigation, replacement or modification of anatomy or a physiological process | Surgical instruments, coronary stents |
| Providing information by means of in vitro examination of specimens from the human body | Certain laboratory analysers (note: overlap with IVDR — see below) |
Accessories to medical devices
An accessory to a medical device is also regulated as a medical device in its own right. Article 2(2) MDR defines an accessory as an article that:
- Is not itself a medical device, but
- Is intended by its manufacturer to be used together with one or more specific medical devices, and
- Specifically enables or assists the device to be used in accordance with its intended purpose, or solely or primarily assists the safety or performance of the device.
Examples include carrying cases for devices, calibration materials, and dedicated software add-ons.
The "intended purpose" principle
The definition hinges entirely on intended purpose — what the manufacturer states the product is for. This is communicated through:
- Labelling and instructions for use (IFU)
- Promotional materials and claims
- Technical documentation
- Any other means by which the manufacturer specifies the intended use
This means:
- A scalpel sold to a butcher is not a medical device. A scalpel marketed for surgical use is.
- A smartphone app that analyses data for fun is not a medical device. An app marketed to diagnose cardiac arrhythmia is.
- Manufacturer intent matters — not how an end user actually uses the product.
Even unintentional or foreseeable off-label use can affect regulatory obligations if the manufacturer is aware of it and does not disclaim it.
The "mode of action" exclusion
A product is not a medical device if it achieves its principal intended action through:
- Pharmacological means (it becomes a medicinal product under Directive 2001/83/EC)
- Immunological means (same — medicinal product)
- Metabolic means (same — medicinal product)
However, a device may be assisted by such means. This gives rise to important borderline categories:
| Product type | Regulatory status |
|---|---|
| Drug-eluting stent | Medical device (MDR) — mechanical action is principal; drug is ancillary |
| Antibiotic-coated wound dressing | Medical device (MDR) — physical barrier is principal |
| Monoclonal antibody treatment | Medicinal product — immunological action is principal |
| Drug-device combination (integral) | Governed by MDR with EMA involvement for the drug component |
Annex XVI — devices without a medical purpose
Regulation (EU) 2017/745 introduced a significant expansion: certain products with no medical intended purpose are nonetheless regulated as medical devices under Annex XVI. These products must comply with MDR despite not being intended to diagnose, treat, or prevent any disease.
Annex XVI currently includes:
- Contact lenses (non-corrective)
- Products intended to be introduced into the body for cosmetic or aesthetic purposes (e.g. dermal fillers)
- Equipment intended to be used to reduce, remove, or destroy adipose tissue (e.g. lipolysis equipment)
- High-intensity electromagnetic radiation equipment (e.g. lasers, intense pulsed light for skin resurfacing)
- Equipment for brain stimulation (non-therapeutic transcranial)
- Equipment emitting ionising radiation for cosmetic purposes
For Annex XVI products, the European Commission publishes Common Specifications that substitute for clinical evidence and GSPR demonstration where applicable.
Software as a medical device (SaMD)
Software is explicitly included in the Article 2(1) definition. Whether standalone software qualifies depends on whether it:
- Is intended to be used for a medical purpose, and
- Performs an action that goes beyond mere storage, archival, lossless compression, or simple search of data.
The MDCG has published detailed guidance on software qualification and classification. See the Software & SaMD page for a full treatment.
Key questions to ask
Before concluding a product is a medical device, work through these questions:
- Is there an intended purpose? Has the manufacturer made claims — in labelling, marketing, or documentation — that suggest a medical purpose?
- Is the intended user human? Veterinary devices are excluded from MDR scope (governed by separate legislation).
- What is the principal mode of action? If pharmacological/immunological/metabolic, it may be a medicinal product.
- Is it an IVD? If the product is used in vitro to examine specimens from the human body, consider IVDR first. See MDR vs IVDR — which applies?.
- Is it an Annex XVI product? Even without a medical purpose, some cosmetic/aesthetic devices fall under MDR.
Related pages
- What is an IVD? — IVDR equivalent definition
- What is not a medical device? — borderlines and exclusions
- MDR vs IVDR — which applies?
- Software & SaMD classification
- Devices incorporating a medicinal substance
Official references
| Reference | Description |
|---|---|
| MDR Art. 2(1) | Definition of medical device |
| MDR Art. 2(2) | Definition of accessory |
| MDR Art. 2(24) | Definition of intended purpose |
| MDR Annex XVI | Non-medical purpose devices |
| MDCG 2019-11 | Guidance on qualification and classification of software |
| MDCG 2022-5 | Guidance on borderline products |