Updated February 2026
(Example of brand name: Trexject)
This sheet is useful if your doctor has recommended injections of methotrexate to improve it's effectiveness or minimise side-effects. It gives information about how you, or a friend or family member, can safely inject methotrexate, the steps to follow and the equipment you will need. For general information on methotrexate, refer to the “Methotrexate” patient information sheet.
The ARA have also developed a patient guide: Safe Disposal of Sharps - Information Leaflet. This patient leaflet outlines how to safely dispose of your methotrexate injection as well as highlighting links and locations where you can dispose of your sharps appropriately.
Injections of methotrexate are given once a week ONLY.
The injection is relatively painless as it uses a fine needle that is inserted just under the skin (subcutaneous). It is often described as the feeling of a slight pinprick and only lasts for a few seconds.
It does not need to be kept in the fridge but should be stored away from heat or light where the temperature stays below 25°C (in a cool pantry or cupboard, not on a windowsill). Ensure it is stored out of the reach of children.
Taking low-dose methotrexate (between 5mg and 25 mg) taken once each week for arthritis or other inflammatory diseases is NOT chemotherapy.
The needle and syringe should only be used once and then thrown away in the sharps container. Never re-use syringes or needles.
DO NOT THROW ANY SYRINGES OR NEEDLES into the general rubbish or recycling.
(For injectable methotrexate in a vial) - Since the methotrexate solution does not contain preservative, it is recommended that it is used once only. However, in some instances vials may be safely used more than once so you should discuss this with your doctor.
When your sharps container is three quarters full, seal and return to the pharmacy where you buy your methotrexate.
If you have forgotten to give yourself an injection at the right time, wait until your nominated day of the week occurs again and then have your weekly dose. DO NOT take a double dose to make up for the forgotten single dose.
If you are given too much methotrexate, you may experience some of the side effects listed under the methotrexate patient information sheet. You should let your doctor know as soon as possible. If you are uncertain about anything, particularly the dose, make sure you check with your rheumatology nurse or doctor first.
The syringes already have the set dose in the syringe, supplied as a pack of 4 (one month supply). It is available as syringes (Trexject) with set doses of 7.5mg/0.15mL, 10mg/0.2mL, 15mg/0.3mL, 20mg/0.4mL and 25mg/0.5mL
When using the Trexject syringes you will need a sharps container for disposing of the syringe after the injection (the company for Trexject can also provide this or it can be obtained from pharmacies). You may also obtain alcohol swabs to clean the skin before injecting.
Injectable methotrexate is supplied in a vial with clear yellow liquid as 50mg in 2ml. Usually five vials are provided on each prescription.
If using the vials as pictured below, you will also need insulin syringes (1ml) which have a fine needle and are recommended for methotrexate injections. These syringes have numbers written along their side to help you draw up the correct amount of liquid for the dose of methotrexate you are taking. Syringes can be bought in bags of 10 at the pharmacy.
The following table tells you how much liquid to draw up for different doses and what number this is on an insulin syringe. Your doctor will usually prescribe a dose between 10 and 25mg. So, for example if your dose is 25mg of methotrexate you will need to draw up 1.0ml. 1.0ml is the number 100 on an insulin syringe.
If you are unsure about your dose or how much liquid you need to inject, check with your GP, pharmacist or rheumatologist before injecting.
This video shows how to inject methotrexate safely.
For further information on methotrexate ask your rheumatologist or go to 'Methotrexate'.