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Prescription quantities

How much medical cannabis am I prescribed each month?

Start with the quantity supplied, not an estimated daily dose. For each product, multiply the number of containers by the amount in each container, then keep grams and millilitres as separate totals.

Published: 19 July 2026Focus: UK private prescriptionsNext review: October 2026

The four details to identify

  1. Product or formulation: flower, oil or another prescribed preparation.
  2. Number of containers: how many packs, tubs or bottles are authorised.
  3. Amount per container: for example 10 g or 10 ml.
  4. Directions: the prescriber’s instructions, which must be read separately from the total quantity.

Simple quantity examples

Two containers × 10 g each = 20 g total.
Three bottles × 10 ml each = 30 ml total.

Do not combine unlike units. A prescription containing 20 g of flower and 30 ml of oil contains two separate quantities—not “50” of one medicine.

Total quantity is not the same as a dose

The total quantity tells you how much medicine has been authorised or supplied. It does not, by itself, tell you how much to use at one time, how long it should last, how much remains, how impaired someone may be, or how much THC may be present in the body.

Do not reverse-engineer a personal dose from the monthly total. Follow the directions given by the prescriber and shown on the dispensing label. Ask the clinic or pharmacy to clarify anything inconsistent or unclear.

Why a “monthly prescription” may not equal a calendar month

Issue dates, dispensing dates, split supplies, product availability and changes agreed with the clinic can make the real period less tidy than one calendar month. Treat each issued prescription and each dispensing label as its own record.

What should I record?

  • Prescription or issue date.
  • Exact product and formulation.
  • Number of containers and amount per container.
  • Total grams or millilitres supplied for that product.
  • The directions exactly as written, without rewriting them into your own dosing rule.
  • Any product not supplied, substituted or awaiting pharmacy fulfilment.

Open Prescription Translator

When to contact the clinic or pharmacy

  • The quantity on the prescription does not match the dispensing label or supplied packs.
  • The directions are missing, unreadable or appear inconsistent.
  • A product was changed or substituted and the updated instructions are unclear.
  • You are unsure whether a repeat, split shipment or outstanding item is still due.

Primary sources and further reading