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Medical AI with numbered sources, for doctors and students

Clinical answers you can check.

Ask the way you’d ask a senior colleague. Every answer cites the guideline or study it came from.

384 guidelines · 9 live sources · For reference and learning, not diagnosis

One account for Prognia, Ward, Suture and Osler

The Osler app icon, a golden head with a network of connected points inside a hexagon, above a glass pedestal

A confident answer without a source is a risk.

A chatbot gives you a fluent paragraph in seconds, and it sounds certain. But which guideline says so, from which year, for which patients? Without a source you cannot check it, and a reference that was made up looks exactly like a real one.

Osler works the other way round. It looks up the evidence first, then writes an answer in which every claim carries the number of its source.

Without a source

For rate control in AF with an ejection fraction above 40%, the first choices are a beta blocker, diltiazem, verapamil or digoxin.

Which guideline? Which year? You cannot tell.

In Osler

For rate control in AF with an ejection fraction above 40%, the first choices are a beta blocker, diltiazem, verapamil or digoxin.[1]

ESC 2024 · AF guidelineSource 1 · guideline

Osler never cites a source it cannot name and link.

How Osler works

Osler is Prognia’s medical AI for doctors and students: ask a clinical question and get an answer in which every claim is numbered to its source (384 international guidelines and 9 live sources including PubMed, Cochrane and ClinicalTrials.gov), as a reference and learning tool, not a diagnosis.

  1. Type your question in your own words, in English, Dutch, German, French or Spanish. Osler searches its guideline library and the live sources at the same time.

  2. The answer appears as it is written. Each statement carries a number right after the claim it supports, so you see exactly what rests on what.

  3. Tap a number to see the guideline or study behind it, with a link to the original. Keep the answer as a Suture note, or turn it into a Ward quiz of 3, 5 or 10 questions.

  1. 1

    Ask it the way you’d ask a colleague

    Type your question in your own words, in English, Dutch, German, French or Spanish. Osler searches its guideline library and the live sources at the same time.

  2. 2

    Every claim numbered to its source

    The answer appears as it is written. Each statement carries a number right after the claim it supports, so you see exactly what rests on what.

  3. 3

    Open the sources, then keep it as a note or a quiz

    Tap a number to see the guideline or study behind it, with a link to the original. Keep the answer as a Suture note, or turn it into a Ward quiz of 3, 5 or 10 questions.

Watch an answer cite itself

An example question, answered the way Osler answers: written as you watch, with a number after every claim. Tap a number to open its source.

You:

Why is SABA-only treatment no longer recommended in asthma?

Osler

A short-acting β2-agonist (SABA) relieves symptoms but leaves the airway inflammation untreated, and SABA-only treatment is linked to more severe exacerbations and, with heavy use, a higher risk of asthma death . GINA therefore recommends that adults and adolescents always receive treatment containing an inhaled corticosteroid, with as-needed low-dose ICS-formoterol as the preferred reliever . A Cochrane review found that as-needed ICS-formoterol roughly halves exacerbations needing systemic corticosteroids compared with a reliever alone . In the SYGMA 1 trial, as-needed budesonide-formoterol lowered the rate of severe exacerbations by 64% compared with as-needed terbutaline .

3 sources used

This is an example answer. Osler can make mistakes, so check the sources before you rely on an answer. For reference and learning, not diagnosis or treatment advice.

An AI medical search engine that shows its work

Made for the questions you look up on the ward, at your desk and the night before an exam.

Numbered sources for every claim

Each claim carries its number where it is made, not in a list at the end. Hover over the number or tap it to see the source behind it.

Never a source it can’t name and link

If Osler cannot trace a passage back to a named guideline, it leaves the passage out rather than cite a bare file number.

384 guidelines and 9 live sources at once

One question searches Osler’s own library of 384 international guidelines and up to 9 live sources in parallel. If one source is slow or unavailable, the others carry on.

Severe drug interactions first

Name two or more medicines and Osler runs an interaction check. A severe interaction is stated at the very top of the answer, before anything else.

How the interaction check works

Fast answers or deeper reasoning

Claude Haiku answers fast on every plan. On Pro and Max you can switch to Claude Sonnet for deeper reasoning on complex questions.

Osler plans and prices

Search your conversation history

Every conversation is kept until you delete it. Search your questions and answers to find one again, even weeks later.

Save an answer as a Suture note

One click turns an answer into a titled note in Suture, with its numbered sources, ready for your own additions.

Turn an answer into a Ward quiz

Choose 3, 5 or 10 questions and Osler turns the answer, with its sources, into a Ward quiz, so you can test yourself later.

Where Osler’s answers come from

Osler’s own library of 384 international guidelines from 25 countries (58,796 searchable passages, from societies such as the European Respiratory Society, IDSA, ASCO, AHA and ACC), plus live PubMed, Europe PMC, Cochrane, ClinicalTrials.gov, DailyMed, OpenFDA, EMA, WHO ICD-11 and an interaction check, in a fixed order of evidence.

Browse the clinical guideline library

The order of evidence Osler follows

  1. 1Guideline library384 international guidelines from 25 countries
  2. 2CochraneSystematic reviews
  3. 3PubMed and Europe PMCPeer-reviewed literature
  4. 4DailyMed and OpenFDAOfficial US drug labels
  5. 5EMAEU product information for centrally authorised medicines
  6. 6Interaction checkWhen a question names two or more medicines
  7. 7ClinicalTrials.govRegistered trials, for new and emerging treatments
  8. 8WHO ICD-11Disease classification

 

Works with Suture, Ward and Prognia

An answer is where learning starts. Keep it, test yourself on it or share it, without copying and pasting.

  1. Suture: a sourced answer becomes a note

    Save an Osler answer to Suture in one click. It becomes a titled note with its numbered sources, which you can edit, link and study from.

    Notes in Suture
  2. Ward: an answer becomes a quiz

    Turn an answer into a Ward quiz of 3, 5 or 10 questions, with its sources, and test yourself on it later.

    Quizzes in Ward
  3. Prognia: ask Osler inside a chat

    In a Prognia conversation, ask Osler and it posts an answer with its sources into the chat, for everyone in it.

    Your Prognia chats

For everyone who needs a checked answer

Students, doctors, nurses and pharmacists use the same Osler. What differs is the question.

Understand the evidence behind what you learn, with the source attached.

A question you might ask

How do SGLT2 inhibitors work in heart failure?

Reference and education. You remain the doctor.

Osler is made by Prognia B.V. in Amsterdam, the Netherlands.

Osler can make mistakes. Check the sources before you rely on an answer. Osler does not diagnose or give treatment advice, and you should never enter information that could identify a patient.

  • For reference and learningLook something up, prepare a presentation, study for an exam. The clinical decision stays with you.
  • No patient dataAsk general clinical questions. Your question is sent to the AI model and the search services that answer it, so never include anything that could identify a patient.
  • Stored in the EUYour account and your conversations are stored in the EU, in Frankfurt. No ads, no selling of data.

Osler in numbers

384 international guidelines from 25 countries, split into 58,796 searchable guideline passages. Up to 9 live sources per question. One app in 5 languages.

Source: the Osler guideline library and code, September 2026.

Frequently asked questions

What is Osler?

Osler is Prognia’s medical AI for doctors and students: ask a clinical question and get an answer in which every claim is numbered to its source (384 international guidelines and 9 live sources including PubMed, Cochrane and ClinicalTrials.gov), as a reference and learning tool, not a diagnosis.

Where do Osler’s answers come from?

From Osler’s own library of 384 guidelines from 25 countries and up to 9 live sources per question: PubMed, Europe PMC, Cochrane, ClinicalTrials.gov, DailyMed, OpenFDA, EMA, WHO ICD-11 and an interaction check. Every claim is numbered to the source it came from.

Does Osler make up sources?

Osler never cites a source it cannot name and link, and every claim carries a number you can open. AI can still make mistakes, so check the source before you rely on an answer.

Can I use Osler for clinical decisions?

Osler is a reference and learning tool. It does not diagnose or give treatment advice; you remain the doctor.

Can I enter patient data?

No. Ask general clinical questions and never enter anything that could identify a patient.

Do I need to be a verified doctor to use Osler?

No. Students, nurses, pharmacists and doctors can all create a free account; there is no NPI or licence check.

Which guidelines does Osler use?

384 guidelines from 25 countries, from societies such as the European Respiratory Society, IDSA, ASCO, AHA and ACC. It does not replace your local or national guidance, so check that too.

Is Osler free?

Yes: 3 questions a day with fast answers on the free plan. Pro gives 15 a day and Max 35, both with the choice of a deeper model.

Can I turn an answer into notes or a quiz?

Yes. One click saves an answer as a note in Suture, or turns it into a Ward quiz of 3, 5 or 10 questions.

Start free. More questions and deeper answers on Pro and Max.

Free: 3 questions a day with fast answers. Pro: 15 a day and Max: 35 a day, both with the choice of the deeper model.

Prognia: your network, spaces, messages, calls and calendar. Free, always.

Save up to 20%

Osler

$7.99/ month

 

Fifteen questions a day and the deeper model

Questions with sources
15 / day
AI models
Fast + deeper (Sonnet)
Drug interaction checks
Included
Conversation history
Included
Priority support
From Max
$4.99/ month

 

More study sessions a day, practice exams and progress insights

Study sessions
Unlimited
Anki deck import
Included
Practice exams
Included
Personal AI study coach
From Max
AI-graded open answers
100 / day

Suture

Discover
$4.99/ month

 

Unlimited notebooks, linked sources and the full atlas

Notebooks
Unlimited
Linked notes & medical sources
Included
Sketches & drawings
Included
AI document actions
7 / day
Knowledge-gap detection
From Max
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