USMLE Step 1 · Step 2 CK · AI tutor and question bank
You’re doing the questions.Make the mistakes count.
Understand why you missed it. Keep one takeaway you’ll use. Know what to practice next.
An adaptive AI tutor that explains it your way, a question bank built for Step 1 and Step 2 CK, and a review after every miss, in one place.
- Free plan, no card
- Paid plans from US$35 a month
- 50% off your first two months at launch
In development. Join the waitlist and we’ll write when you can try it. Free to join, no card. The Free plan and the half-price offer start when we open.
The review
The questions are quick. The review is where your hours go.
Preparation takes its hours from somewhere: evenings, the gaps between other commitments, weekends that had other plans. Most of that time goes on questions, and a question is quick. The slower part comes after: working out why you chose what you chose, writing something worth keeping, and deciding what to do with tomorrow’s hour. Some of it may sound familiar:
- A review that takes longer than the block did.
- The same kind of question missed a third time, with no clear reason why.
- Notes that grow faster than you can use them.
An explanation tells you why the answer is right. It doesn’t always show where your own reasoning turned, or whether the miss was a gap in knowledge, a detail misread or a step skipped. Without that, review tends to become rereading.
ClintixPro is built for exactly that moment: the part after a miss. It finds the likely reason, keeps one takeaway and points you at what to practice next.
Why ClintixPro
Built around understanding, not only recall.
A question bank can tell you whether you were right. This exam asks for more: weighing a stem, choosing a next step, noticing what doesn’t fit. ClintixPro gives you three things that work together, so practice and what you miss inform what comes next.
Layer 01
A tutor that explains it your way
Candidates arrive from many medical schools and curricula, so the same concept may need a different starting point. Ask the tutor to explain it simpler or deeper, or from another angle, and keep following up until it clicks. It builds from the simple idea up to the complex one, so a hard topic arrives in steps you can follow. If an explanation doesn’t look right, tell us and our team will review it.
Layer 02
A question bank built for Step 1 and Step 2 CK
ClintixPro generates its practice questions with AI built specifically for the USMLE, so the questions and the explanations behind them are scoped to Step 1 and Step 2 CK rather than to medicine in general. You can practice entirely in it.
Layer 03
A review that turns every miss into a next step
After a miss there are three jobs: decide why it happened, write something down, and decide what to study next. ClintixPro drafts all three in one place, and you confirm, edit or skip as you see fit.
Already have a question bank, notes or flashcards you like? Keep them. Upload a screenshot of a question you missed and review it here. ClintixPro doesn’t connect to other providers’ products, and you should only upload content you’re entitled to use.
The tutor
Ask until it makes sense.
Preparing for Step 1 or Step 2 CK means bringing a lot of knowledge together. Sometimes you need to revisit the underlying science. Sometimes you need to work through a clinical decision.
Ask ClintixPro to explain it more simply, go deeper or approach it from another angle. Follow up on the part that still isn’t clear, and work through the reasoning at your own pace, until it’s yours.
Practice with the question bank, explore a topic with the tutor or use a missed question as the starting point for a conversation.
Say you’ve just missed the potassium question in the Step 1 example below. You open the tutor, ask for the answer, then ask for more, and then for the same point from another side.
You ask · The answer
In DKA the serum potassium was 5.6, but I’m told total body potassium is low. Why?
The tutor
Think of potassium as living mostly inside cells, with insulin helping to keep it there. In DKA there is no insulin, and the very high glucose draws water, and potassium with it, out of cells. So the blood level looks high while the body is already losing potassium through the extra urine. Serum shows where the potassium is, not how much there is.
You ask next · Deeper
Go deeper.
The tutor
Three things push potassium out of cells. Insulin deficiency reduces Na⁺/K⁺-ATPase activity, so less goes back in. Hyperosmolality pulls water out of cells and carries potassium with it. Acidemia shifts potassium out as hydrogen ions move in, though less in an organic acidosis like DKA than in a mineral acid acidosis.
Meanwhile osmotic diuresis, and any vomiting, remove potassium from the body. So potassium is shifted out of cells and lost from the body at the same time, and the serum value only reflects the first.
You ask next · Another angle
Approach it from the treatment side.
The tutor
Insulin moves potassium back into cells. If the total was already low, giving insulin can drop the serum level quickly, which is why potassium is checked before insulin is started and replaced if it is low. A serum value of 5.6 at the start is a reason to expect that fall, not to relax.
The product experience
One missed question, from start to finish.
Example question · written for this page
A 19-year-old woman with type 1 diabetes mellitus is brought to the emergency department with 1 day of nausea, vomiting, and abdominal pain. She has not taken insulin for 2 days. Temperature is 37.0°C (98.6°F), pulse is 118/min, respirations are 28/min and deep, and blood pressure is 96/60 mm Hg. Mucous membranes are dry. Laboratory studies show:
Serum: Na⁺ 131 mEq/L · K⁺ 5.6 mEq/L · Cl⁻ 94 mEq/L · HCO₃⁻ 8 mEq/L · glucose 560 mg/dL. Arterial pH 7.12. Urine ketones: strongly positive.
Which of the following best describes her total body potassium and the reason for her serum potassium concentration?
- AIncreased; reduced renal excretion due to acidemia
- BIncreased; impaired cellular uptake due to insulin deficiency
- CNormal; serum concentration reflects total body storesyour answer
- DDecreased; serum concentration raised by shift out of cells✓ correct
- EDecreased; serum concentration raised by reduced renal excretion
The reasoning gap
A serum value was read as a measure of stores.
Most potassium is inside cells, so the serum level reflects distribution as much as stores. Here, insulin deficiency and hyperosmolality move potassium out of cells and hold the serum value up, while osmotic diuresis and vomiting drain the body of it. The serum value looks high; the body is depleted.
Why each option
Notes on each option
- A
- Acidemia isn’t the driver here. Osmotic diuresis increases urinary potassium loss, so renal handling adds to the depletion.
- B
- Right mechanism, wrong conclusion. Insulin deficiency does impair uptake, but that shift is what keeps the serum value up while stores fall.
- C
- Serum potassium is a poor guide to stores while potassium is being shifted.
- D
- Correct. Shift out of cells raises the serum value; urinary and gastrointestinal losses deplete the total.
- E
- Right total, wrong mechanism. Renal excretion is increased, not reduced.
Takeaway, in your words
DKA: serum K⁺ can be high while total body K⁺ is low (shift out of cells, plus osmotic diuresis). Insulin drives it back in, so watch it.
A draft. Rewrite it so it sounds like you.
Next study action
Do five questions where a lab value and the underlying picture differ: potassium, phosphate and sodium in DKA. For each, say whether the value reflects stores or distribution.
Accept it, change it or skip it.
Example question · written for this page
A 28-year-old woman comes to the emergency department with 1 day of right-sided chest pain that is worse on deep inspiration. She had a mild upper respiratory infection last week and still has a cough. She takes a combined oral contraceptive. Temperature is 37.2°C (99.0°F), pulse is 84/min, respirations are 16/min, blood pressure is 118/74 mm Hg, and oxygen saturation is 98% on room air. The lungs are clear. There is no leg swelling or tenderness. She has no hemoptysis, recent surgery or immobilization, and no personal or family history of venous thromboembolism. A chest x-ray shows no abnormalities. An ECG shows normal sinus rhythm without ST-segment changes. A urine pregnancy test is negative.
Which of the following is the most appropriate next step in management?
- ACT pulmonary angiographyyour answer
- BSerum D-dimer✓ correct
- CVentilation–perfusion scan
- DDuplex ultrasonography of the lower extremities
- EDischarge with analgesia and no further testing
The reasoning gap
Imaging came before the probability.
Her Wells score is 0 and nothing in the stem makes a PE likely: normal pulse and oxygen saturation, no leg signs, no prior VTE, no recent surgery, and a recent cough as a plausible alternative. Probability is low, so the cheapest question comes first. The one detail that stops her being sent home is the estrogen-containing contraceptive, which means PERC can’t clear her.
Why each option
Notes on each option
- A
- The right tool at the wrong moment. CT angiography is for intermediate or high probability, or a positive D-dimer. Here it adds radiation and contrast exposure, and the risk of incidental findings, for a patient unlikely to have a PE.
- B
- Correct. Probability is low but PERC can’t clear her, so a D-dimer decides whether imaging is needed at all.
- C
- Reserved for when CT is unsuitable (for example, in pregnancy or with contrast allergy), and not the first test here.
- D
- She has no leg symptoms or signs to chase.
- E
- Tempting, but estrogen use means PERC isn’t met, so testing can’t be skipped.
Takeaway, in your words
Low pretest probability but PERC fails (estrogen): D-dimer first. Imaging only if it’s positive or probability is higher.
A draft. Rewrite it so it sounds like you.
Next study action
Do five suspected-PE questions. Before each answer, say how likely PE is, then choose the test.
Accept it, change it or skip it.
See how each step worksWant this for your own misses? Join the waitlist
Who is behind it
Built by physicians who know what exam preparation asks of you.
ClintixPro is built by Clintix, an Australian company founded by three practicing emergency physicians. It already helps Australian doctors prepare for their specialty exams, and the USMLE version brings the same approach to a new exam.
Dr. Alastair MacKinlay
Dr. Bassam Nuseibeh
Dr. Jonathan Claydon
A team that listens. We’re a small, responsive team, so what you tell us reaches the people who build ClintixPro. If a question, an explanation or a suggestion doesn’t look right, or something just isn’t clear, write to hello@clintix.com. Our team will review it, and where something needs correcting, we’ll correct it.
Content and quality. As ClintixPro for USMLE nears launch, Content and quality will set out how questions and explanations are produced, which references they draw on and how the content is reviewed. ClintixPro isn’t affiliated with the USMLE, NBME or FSMB; Important information has the details, including how to read the readiness score.
The offer
What you get, and what it costs.
Judge it for yourself, ideally before you spend anything. There is a Free plan with no card, new subscribers pay half price for their first two months, and nothing is charged on the waitlist.
- Start free
Free plan, no card
When access opens, you can start with 10 AI-generated questions a day, 5 tutor questions a day and one free mock exam. Nothing can be bought or tried yet; the waitlist is how you’ll hear when you can.- Price and terms
From US$35 a month
Starter, Standard and Intensive, with 50% off your first two months when you subscribe within six months of launch. Monthly plans can be cancelled at any time. Pricing and terms.- Includes
Everything you need
An adaptive AI tutor that explains at the depth you ask for; ClintixPro’s own question bank with feedback pitched at the exam’s pass standard; the review after a miss; screenshot upload for misses from other question banks; and, on Standard and Intensive, a readiness score, which is an estimate and not a promise. It doesn’t connect to other providers’ products.- Exams
Step 1 and Step 2 CK
Both are open to the waitlist while ClintixPro for USMLE is in development.
Updated 27 October 2026.
The next step
Be ready when it opens.
Join the waitlist and we’ll write when Step 1 and Step 2 CK are ready to try. It’s free to join and needs no card, and when we open, new subscribers pay half price for their first two months.
- Enter your email. The two other questions are optional.
- You’ll see a confirmation on screen.
- We’ll write when there’s something real to try. Nothing is charged on the waitlist.