Common Registration Assessment, Part 1

Liraglutide daily injection dose steps and pen supply for the GPhC assessment

Three original practice questions, with the working shown. Read the stated prescription or plan before calculating.

Published 4 November 2026. Independent revision material, not GPhC questions, not for patient care.

A woman using an injection pen at home
Photo from Pexels, used under the Pexels licence. It is a stock image and does not show the exercise.

The manufacturer's UK product information for a liraglutide 6 mg/ml pre-filled pen for weight management states that the starting dose is 0.6 mg once daily, increased in 0.6 mg increments with at least one week between steps to improve gastro-intestinal tolerability, up to a maintenance dose of 3.0 mg once daily.

The same information states that one pre-filled multidose pen contains 18 mg of liraglutide in 3 ml, and its dose-escalation schedule uses once daily doses of 0.6 mg, 1.2 mg, 1.8 mg and 2.4 mg before the 3.0 mg maintenance dose.

It also states that daily doses higher than 3.0 mg are not recommended.

Each question fixes the values needed for its arithmetic. Write the unit beside every step and distinguish a single dose from a pen content or a supply period. All prescriptions and patients here are fictional; these are revision materials, not for patient care.

The method

  1. Identify the stated daily dose step in milligrams.
  2. Divide the pen content of 18 mg by the daily dose to find how many days one pen lasts.
  3. Divide the supply period by the days per pen, rounding up to whole pens when needed.
  4. Keep milligrams, days and pens separate; convert only when the question asks.

Three practice questions

Work each one on paper first, then open the answer. All patients and prescriptions are fictional.

Question 1

A fictional patient starts liraglutide at 0.6 mg once daily, and the dose is increased by 0.6 mg every week: 0.6 mg in week one, 1.2 mg in week two, and so on. In which week does the 3.0 mg maintenance dose start?

Show the answer

Answer: Week 5

Working: Week 1 is 0.6 mg, week 2 is 1.2 mg, week 3 is 1.8 mg, week 4 is 2.4 mg, so 3.0 mg starts in week 5.

Question 2

A fictional patient stays on liraglutide 0.6 mg once daily. One pre-filled pen contains 18 mg. How many days does one pen last?

Show the answer

Answer: 30 days

Working: 18 mg / 0.6 mg per day = 30 days.

Question 3

A fictional patient takes the liraglutide 3.0 mg once daily maintenance dose. How many 18 mg pens are needed for 30 days?

Show the answer

Answer: 5 pens

Working: One pen lasts 18 mg / 3.0 mg per day = 6 days. 30 days / 6 days per pen = 5 pens.

eMC SmPC: BIOLIDE 6 mg/ml solution for injection in pre-filled pen

https://www.medicines.org.uk/emc/product/100249/smpc

Where marks are lost

  • Using the 6 mg/ml concentration as the daily dose instead of the stated milligram dose step.
  • Dividing 18 mg by the daily dose but forgetting to round up when a partial final pen is needed.
  • Confusing the week of dose escalation with the number of pens required.

Frequently asked questions

Are these official assessment questions?

No. They are original revision exercises, not official GPhC questions and not for patient care.

Does one pen always last the same number of days?

No. The 18 mg pen lasts for a different number of days at each daily dose step. Divide 18 mg by the stated daily dose.

How should I check the answer?

Check the requested unit, then work backwards from the quantity to the stated dose and duration.

Sources

The questions above are original and use fictional patients and prescriptions. PreRegExamPrep is not affiliated with or endorsed by the General Pharmaceutical Council.

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More calculation topics

See also the formula sheet, the eight sample questions and the approved calculator page.