for better mental health


Explains what antipsychotics are used for, how the medication works, possible side effects and information about withdrawal.

What's a depot injection?

A depot injection is a slow-release, slow-acting form of your medication. It isn't a different drug – it's the same medication as the antipsychotic you're used to taking in tablet or liquid form. But it's administered by injection, and it is given in a carrier liquid that releases it slowly so it lasts a lot longer.

Key facts about depot injections

  • You would usually only be offered a depot injection if:
    • you've already been on your medication for a while and you know it's working well for you
    • you expect to keep taking it for a long time
  • Injections are usually given every two, three or four weeks, depending on the drug.
  • Your injection will usually be given by a health care professional in a community setting (such as a regular clinic, medical centre or in your own home). You would never be given this kind of drug formulation to manage and administer at home by yourself.
  • The injection is made into a large muscle – usually either your buttock, or the largest muscle of your shoulder.
  • It's a good idea to alternate between different muscles and sides of your body, to help prevent any injection site problems.

Not all antipsychotics are available as depot injections. For information on the available forms of specific drugs see our antipsychotics A-Z or look at our page on comparing antipsychotics.

Why might I choose a depot injection?

A depot injection might be a good option for you if:

  • you have difficulty swallowing medication
  • you have difficulty remembering to take medication regularly
  • you prefer not to have to think about taking medication every day

You may also be given a depot if your doctors agree that you need the drug but feel that you will not take it regularly as prescribed.

Injection site problems

If you regularly have your injection in the same place in your body, you may start to experience problems with that part of your body, such as:

  • abscess
  • bleeding
  • bruising
  • irritation
  • lumps
  • numbness
  • pain
  • redness
  • soreness
  • swelling

If you do have problems with your injection site, make sure you mention this to your doctor, nurse or whoever administers your medication.

Patient Information Leaflet (PIL)

As you don't pick up a prescription for a depot injection, you may not be given the Patient Information Leaflet (PIL) which would usually come in the drug packet. It's always a good idea to read the PIL carefully before taking any medication, so if you aren't given it you should ask for a copy from the person who gives the injection, or your doctor or local pharmacist.

This information was published in 2016. We will revise it in 2019.

References are available on request. If you would like to reproduce any of this information, see our page on permissions and licensing.

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