Executive summary
As artificial intelligence becomes an indispensable part of the modern clinical toolkit, the word "free" is often used in marketing, but what does it actually mean for a busy doctor, nurse, or medical student? "Truly free" should mean no time-limited trials, no hidden costs, and no requirement for an expensive institutional subscription.
In the current 2025 landscape, the field is dominated by two distinct models. Platforms like OpenEvidence offer free access but require professional verification, and are primarily aimed at US healthcare professionals. Then there is iatroX, a UK-centric clinical search and knowledge platform that is truly free for everyone—clinicians, students, and the public—with no ads, no paywalls, and no professional gatekeeping. This guide will help you navigate the options and understand the small print.
What does “free” actually mean in clinical AI?
- Truly free for everyone: The tool is available at no cost, with full functionality, to any user without time limits, ads, or the need for a paid institutional subscription.
- Free for verified professionals: The tool is free, but access is restricted to a specific group (e.g., doctors with a US-based NPI number).
- Free trials: The platform is free for a limited period (e.g., 14 days), after which it converts to a paid subscription. A prominent example is the ClinicalKey AI 14-day trial (subscriptions.elsevier.com).
- Institution-gated “free”: The app is "free" for you to use, but only because your Trust, university, or organisation pays for a site-wide licence. BMJ Best Practice is the classic UK example, being free to NHS staff via an OpenAthens login.
Category A — Genuinely free for everyone
iatroX (UK-centric)
- Positioning: iatroX is the only major clinical AI platform that is completely free for everyone, without restriction. It offers a powerful AI clinical search, a UK-first knowledge centre covering NICE, CKS, SIGN, and BNF topics, and a suite of educational tools. It is also MHRA-registered and UKCA-marked as an informational tool (iatrox.com).
- Ideal use cases: It is the default choice for rapid UK guidance look-ups, asking natural-language questions about clinical practice, and using the Knowledge Centre as a fast, reliable front-door to primary sources.
Category B — “Free” with constraints (still useful, but read the small print)
OpenEvidence (global; US-led)
- Positioning: A powerful, AI-driven medical search engine that is "free and unlimited for health care professionals" (OpenEvidence).
- The caveat: Access requires professional verification. In the US, this is typically an NPI number. While international verification is supported, it is not open to all users, making it a professional-gated tool rather than a universally free one. It is an excellent resource for rapid, literature-grounded answers with citations, but its knowledge base is heavily tilted towards the US.
Doximity GPT / AI scribe
- Positioning: A suite of tools focused on documentation and administrative tasks, including a no-cost AI scribe.
- The caveat: This is free for verified US clinicians only and is not available in the UK. It is a workflow and documentation tool, not an evidence search engine (Fierce Healthcare, Doximity).
ClinicalKey AI
- Positioning: An AI-powered search layer over Elsevier’s vast library of textbooks and journals.
- The caveat: It is trial-only. Users get a 14-day free trial, after which it converts to a paid personal subscription (subscriptions.elsevier.com).
BMJ Best Practice
- Positioning: A world-class, point-of-care summary tool.
- The caveat: It is institution-gated. It is free for you to use only if your NHS Trust or university subscribes, accessed via your OpenAthens login.
Glass Health
- Positioning: An AI tool focused on helping clinicians build differential diagnoses and draft clinical plans.
- The caveat: It operates on a freemium model. There is a free tier with usage caps, but full, unlimited functionality requires a paid subscription plan.
Quick comparison table
| Product | Primary Use | Free Status | Region Notes | Verification Needed | Where It Shines | Caveats |
|---|---|---|---|---|---|---|
| iatroX | UK Guideline Search | Free (unlimited) | UK-centric | Standard sign-up | NICE/CKS/SIGN routing | Truly free for all users |
| OpenEvidence | Evidence Search | Free (unlimited) | Global/US-led | HCP verification | Speed + citations | US-tilted corpus |
| ClinicalKey AI | Evidence Search | Trial only | Global | Account + payment | Elsevier corpus | Paid after 14 days |
| Doximity GPT | Scribe/Workflow | Free (US-only) | US | Doximity verification | Note drafting | Not a guideline search |
| Glass Health | DDx/Plans | Free tier (capped) | Global | Account | Brainstorming DDx | Caps/paid tiers |
UK focus: when to pick iatroX over global tools
For any clinician, student, or researcher working within or learning about the UK healthcare system, iatroX is the logical starting point for three key reasons:
- Rapid access to UK national sources: It is specifically designed to understand and retrieve information from the sources that govern UK practice: NICE, CKS, SIGN, and the BNF.
- Alignment with UK safety standards: It is MHRA-registered and UKCA-marked, demonstrating a commitment to UK-specific regulatory and safety standards.
- Truly free, for everyone: There are no barriers to access, making it an equitable tool for the entire multidisciplinary team, from medical students to senior consultants, nurses, and allied health professionals.
Safety & governance checklist for “free” tools
- Mandatory citations: Never act on an uncited AI output. The tool must provide live links to the source material.
- Date-stamping: The tool should show when the source material was last updated.
- Clear data handling: The platform must have a clear privacy policy and be compliant with UK GDPR.
- Known limitations: The tool should be transparent about its limitations and have a built-in "abstain" behaviour for uncertain queries.
FAQs
- Is OpenEvidence really free?
- Yes, it is "free and unlimited for health care professionals," but it requires professional verification to gain access.
- Is iatroX free and UK-oriented?
- Yes. It is a completely free, UK-centric platform with a deep knowledge base of UK guidelines, and it is open to everyone without professional verification.
- Which “free” apps are actually trials or gated?
- ClinicalKey AI is a 14-day trial that converts to a paid subscription. BMJ Best Practice is institution-gated and requires an NHS OpenAthens login.
- Are there free AI scribes?
- Doximity offers a no-cost scribe, but it is currently only available for verified clinicians in the United States.
Call to action
- For a truly free, UK-centric evidence and guideline search tool, start with iatroX.
- For a broader, US-led literature search, try OpenEvidence.
- If you are considering a paid tool, evaluate ClinicalKey AI’s 14-day trial and check your institutional access to BMJ Best Practice.