Side effects and advice
Methotrexate injections for skin conditions
Methotrexate injections are a safe and effective treatment when used carefully. Most people do not get any side effects.
Serious side effects are rare and happen to less than 1 in 10,000 people. Some side effects happen immediately but others can take a few weeks to develop.
Contact your doctor or call 111 if you:
- are sick (vomit) often
- bruise or bleed easily, including from the nose or gums
- feel very sick (nausea) or have bad stomach pain
- get a high temperature, chills, sore throat or infection
- get chest pain or breathlessness
- get more itchy than usual
- get yellowing of your skin or whites of your eyes – this can be harder to see on black or brown skin
- have a rash, blisters or ulcers in your mouth or on your tongue
- have a dry cough that does not go away
- have diarrhoea that does not stop
- have soreness or ulcers in your vagina
- regularly have dark urine when you pee
If these symptoms are serious and you feel very unwell, go to your nearest A&E.
If you get these side effects, stop injecting methotrexate immediately until you talk to a doctor. These symptoms can be a sign of bone marrow damage, fibrosis in your lungs, liver problems or dehydration.
Infections while on methotrexate
Taking methotrexate can mean you're more likely to get infections.
Contact your doctor immediately if you:
- get symptoms of chickenpox or shingles
- come into contact with someone who has chickenpox or shingles
- come into contact with a child who has recently had a vaccine
Taking other medicines while on methotrexate
Other medicines can affect how methotrexate works in your body.
Always check with your doctor or pharmacist before taking any other medicines. Tell them you’re taking methotrexate.
This includes medicines you buy at a pharmacy or shop, such as:
- painkillers
- cold, cough and flu medicines
- herbal medicines
Tell us if you’ve been prescribed other medicines such as:
- acitretin
- isotretinoin
- phenytoin
Be especially careful about taking:
- aspirin, including any cold and flu medicines containing aspirin
- non-steroidal anti-inflammatory drugs, including ibuprofen and any creams or ointments for joint pain
- antibiotics containing trimethoprim
If you’re looking for medicines because you’re getting side effects, stop taking methotrexate and contact your healthcare team for advice.
Pregnancy and methotrexate
Methotrexate is not recommended in pregnancy, as it can harm a developing baby. Make sure you use contraception if you have sex while on methotrexate.
Methotrexate can also reduce fertility by damaging sperm and egg production.
If you or your partner are planning to get pregnant, talk to your doctor. We’ll discuss if you need to change your treatment before stopping contraception, so you can have a baby safely.
You should wait at least 6 months after finishing your treatment before trying to get pregnant. Keep using contraception during this time.
If you become pregnant while taking methotrexate, stop using your injections and talk to your doctor or a GP as soon as possible.
Alcohol and methotrexate
Avoid drinking alcohol during your methotrexate treatment. Methotrexate and alcohol can both cause liver damage.
If you do drink alcohol, do not drink more than 14 units of alcohol a week. Make sure you have some days where you do not drink any alcohol at all.
The risk of liver damage from methotrexate is higher in people who take it for psoriasis than in people who take it for rheumatoid arthritis. Alcohol increases this risk even more.
Talk to your doctor if you want advice about drinking alcohol.
Food and methotrexate
Methotrexate can reduce your body’s ability to fight infection. Some foods contain bacteria that can make it more likely for you to get an infection.
The risk of infection from these foods has not been directly linked with taking methotrexate injections, but it’s best to avoid them. This includes:
- food made from unpasteurised milk, like soft cheese
- uncooked meats, like pâtés
Read food labels carefully and avoid eating these types of food.
Remember to wash your hands before preparing and eating food.
Vaccines and methotrexate
It’s safe for you to have:
For any other vaccines, check with your doctor or nurse.
Travel and methotrexate
If you’re travelling with your injections, put them in your hand luggage.
Contact us for a letter confirming that you have been prescribed methotrexate injections. You need this to travel with your injections.
If you need to take any vaccines before you travel, check with your doctor or nurse before taking them.
Resource number: 4603/VER2
Last reviewed: December 2025
Next review due: December 2028
