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About morphine

Morphine is a strong painkiller. It's used to treat severe pain, for example after an operation or a serious injury, or pain from cancer or a heart attack.

It's also used for other types of long-standing pain when weaker painkillers no longer work.

Morphine is available only on prescription. It comes as tablets, capsules, granules that you dissolve in water, a liquid to swallow or an injection. Morphine injections are usually only done in hospital.

Key facts

  • Morphine works by blocking pain signals from travelling along the nerves to the brain.
  • The most common side effects of morphine are constipation, feeling sick and sleepiness.
  • It's possible to become addicted to morphine, but your doctor will explain how to reduce the risks of becoming addicted.
  • It may be best not to drink alcohol while taking morphine as you're more likely to get side effects like feeling sleepy.
  • Morphine is a controlled medicine. When you collect it your pharmacist will ask for proof of your identity such as your passport or driving licence. You'll also be asked to sign the back of your prescription, to confirm that you've received it.

Page last reviewed: 26 January 2022
Next review due: 26 January 2025