ClinicalKey vs Primum
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
ClinicalKey
This app provides medical professionals with instant access to a vast library of clinical knowledge, including synoptic content and in-depth reference materials. It helps users stay updated on medical advancements, confirm diagnoses, and advance their research skills, all while offering CME/MOC/CE credits.
- Access to 30+ medical specialties
- Synoptic content for quick answers
- Full-text reference books and journals
- Mobile-optimized medical calculators
- Earn CME/MOC/CE credits
- Intuitive search functionality
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INSTITUTIONAL SUBSCRIPTION REQUIRED. Access the latest advances in clinical knowledge anytime, anywhere with ClinicalKey®- the essential resource for medical professionals. ClinicalKey combines the speed of synoptic content with the depth of a comprehensive clinical reference tool in one intuitive solution to provide clinicians trusted information in the moments that matter most. With ClinicalKey, you can: • Stay abreast of rapidly expanding clinical knowledge • Quickly confirm diagnosis and treatment information • Advance critical thinking skills and research Please note: To access our extensive content library, ensure you have a subscription to ClinicalKey from your organization. To get started: 1. Download the free ClinicalKey app for iOS on your iPad® or iPhone®. 2. Follow the prompts to connect to your organization’s account.The app will ask questions to get you to the right content. 3. Choose the method of access that is right for you: 4. Select Access via Network if you need a quick answer and your device is connected to your organization's network. 5. Select Access via Institution for other ways to connect. 6. Once you have gained access, create or sign- in to your Elsevier ClinicalKey user account to save favorites and earn CME/MOC/CE/MOC/CE. ClinicalKey® Because you want to find a better way to help your patients ClinicalKey combines the speed of synoptic content with the depth of a comprehensive clinical reference tool in one intuitive solution to give clinicians trusted information in the moments that matter. With the ClinicalKey, clinicians will be able to: • Enhance patient care with trusted resources and deep insights across 30+ specialties • Combine efficiency and confidence in your practice with access to quick answers and information that is continuously updated • Excel in your field by building foundational knowledge and keeping up with the latest trends through full-text reference books and journals, while earning free CME/MOC/CE credit • Stay abreast of rapidly expanding clinical knowledge • Quickly confirm diagnosis and treatment information • Advance critical thinking skills and research ClinicalKey App for iOS Features: • Trusted Comprehensive content covering more than 30 medical and surgical specialties • Easy-to-scan, clinically focused medical topic synopses • Intuitive search with auto-suggest/ • Easy search with auto-completion • Direct navigation to your favorite books and journals • Mobile-optimized medical calculators • Access to full-text books, full-text journals, guidelines, multimedia and more • Access via Institutional IP; individuals will not be able to earn CME/MOC/CE, save, or share content when using IP authentication. Please register for remote access via your institutional web version of ClinicalKey. ClinicalKey Registrants (non-IP) customers will enjoy: • Opportunity to earn CME and fulfill MOC requirements with the American Board of Internal Medicine (ABIM) • Ability to favorite and save content • Option to print and email topics, videos or graphics • Earn and track free CME/MOC/CE credit Ability to favorite and save content Print and email topics, videos or graphics to patients and colleagues iPad and iPhone are trademarks of Apple Inc, registered in the US and other countries.
Primum
Connect with expert oncologists for case-specific advice and treatment decision support. This app facilitates direct messaging with specialists, offering actionable insights and a platform to manage your inquiries efficiently.
- Search and filter expert oncologists
- Direct messaging with specialists
- Real-time chat and notifications
- Case-specific advice
- Inbox management
- Reference past inquiries
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Sometimes even the experts need experts. Primum helps oncologists get more confidence in their treatment decisions by making it easy to find other expert oncologists and get actionable, case-specific advice fast. The official Primum app puts high-quality advice from expert oncologists in your pocket. "Prompt response. Excellent suggestions outlining the different treatment options/approaches for a rare clinical scenario without much data in the literature to guide decision making" - Community Oncologist, FL "It was really helpful to hear the expert recommendations and I agree with his recommendations. This topic is quite interesting and difficult to deal with. I appreciate a lot the recommendations." - Community Oncologist, MA "Very detailed response, clear thought process, mentioned experience with similar case. Overall - excellent!" - Community Oncologist, CT Find and select an expert - Search with keywords or phrases - Filter for expertise based on focus area - Review their experience before choosing to message Message an expert directly - Choose the expert you wish to message - Submit a brief description of your question directly to your chosen expert - Chat in real-time if you are both online, or get notified when they respond Get notified of important inquiry updates - See when you have unread messages - View the count of unread messages - Receive text and/or email alerts when you get a new message, a new inquiry, or when an inquiry is closed Rate your experience - Submit ratings and feedback on every question, to help Primum and our experts improve Manage your inbox - Keep your inbox uncluttered and focused by closing inquiries once they have been answered Reference past questions - View all closed inquiries to refer to past questions and answers
Screenshots
Verdict
The clearest difference is review sentiment: Primum at 100% against ClinicalKey's 9%. Primum also leads on monetization model (ad-supported vs subscription). ClinicalKey's advantage is ads (none vs shown). On price, update cadence, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
ClinicalKey ships an update every 5 weeks, Primum every 2 months. The most recent releases landed on September 14, 2026 and August 4, 2026 respectively.
| Parameter | ClinicalKey | Primum |
|---|---|---|
| Price | Free | Free |
| Rating | — | 4.2 (5 ratings) — better |
| Positive reviews | 8.8% of reviews | 100.0% of reviews — better |
| Number of ratings | — | 5 — better |
| Update frequency | Every 5 weeks — better | Every 2 months |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Subscription | Ad-supported — better |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 15.0 — better | 15.1 |
| Further details — not scored | ||
| Size | 55 MB | 53 MB |
| Age rating | 12+ | 17+ |
| Developer | Elsevier Inc. | PRIMUM HEALTH, INC. |
Customer experience
ClinicalKey
Primum
Bugs and requests
ClinicalKey
Reported bugs
14 issues- App stuck on loading screen after initial login
- Forced logout when closing or minimizing app
- Institutional login not working despite web access
- App crashes during search queries
- OpenAthens authentication failures
Show 9 moreShow fewer
- Network change warnings appearing incorrectly
- Search results returning unrelated content
- Textbook search not finding available books
- App won't load after recent updates
- Blank search results for valid queries
- Scrolling in table of contents sidebar not functioning
- Landscape orientation not supported
- App doesn't remember page position when reopened
- Restricted access to books after updates
Requested features
10 requests- PDF download capability within the app
- Favorite/bookmark textbooks and articles
- Landscape mode support for iPad
- Find-on-page text search function
- Automatic session persistence and page memory
Show 5 moreShow fewer
- Text size and screen color customization
- Fingerprint/passcode login option
- Browse feature with category filtering
- Offline access to downloaded materials
- Feature parity with website version
Primum
Not enough reviews yet to summarise bugs or requests.
In-app purchases
ClinicalKey
No in-app purchases
Primum
No in-app purchases







