Also called enoxaparin

Clexane is an anticoagulant used to treat and prevent blood clots, which can block your blood vessels. Find out how to use it safely and possible side effects.

Type of medicine Also called
  • Anticoagulant (also called 'blood thinner')
  • Belongs to a group of medicines known as low molecular weight heparins
  • Clexane®
  • Clexane Forte®

What is Clexane?

Clexane is an anticoagulant or 'blood thinner'. It is used to treat and prevent blood clots, which can block your blood vessels. Clexane helps to reduce the risk of blood clots in your blood by stopping them from forming. If blood clots have already formed, Clexane can be used to reduce their size by breaking them down. 

Clexane is often prescribed after operations (surgeries) such as hip or knee surgery, or abdominal surgery, when your risk of getting blood clots is increased. Clexane is also used if a blood clot has already formed in your heart (heart attack), leg (deep vein thrombosis) or lungs (pulmonary embolism).

Clexane is given as an injection under your skin. It comes as a pre-filled syringe, which means the syringe comes filled with the medicine in it. It is ready for use.

How to use Clexane

The dose of Clexane is different for different people, depending on its use, your body weight and how well your kidneys are working. Your doctor will work out the best dose for you.

Clexane is given as an injection just under your skin (called subcutaneous injection).

Note: There are 2 Clexane injection devices. From July 2020, the new Clexane device with safety lock injection has replaced the old Clexane device without safety lock injection.  

If you are unsure about how to inject Clexane, ask your doctor, nurse or pharmacist to show you.

Video on how to inject Clexane®

If you click on the arrow below, you can watch 2 videos, one for the Clexane device with safety lock and one for the old Clexane device without a safety lock.

If you are unable to inject Clexane yourself, ask a family member or somebody you live with to learn how to give you the injection. If this is not possible, your GP may be able to arrange for a nurse to give you the injections in your home, or for you to go to a clinic. But you may need to have injections on weekends, and some people need to have injections twice daily.

Handy tips 

  • Dose: Your healthcare provider will teach you how to measure your dose. You may need to use all of the syringe OR discard some first. You may notice an air bubble in the syringe. This is supposed to be there. Do not try to remove it. Inject your Clexane dose at the same time each day.   
  • Injection site: Change injection sites each time to stop your skin from hardening.
  • Missed dose: If it is nearly time for your next dose, skip the missed dose and inject your next dose at the usual time. Otherwise, inject the missed dose as soon as possible. Do not inject 2 doses at the same time. Contact your doctor if you miss 2 or more doses in a row.
  • Inform health professionals: It is important to let health professionals know that you are taking Clexane, such as your dentist, pharmacist, podiatrist or nurse.
  • Storage: Keep your Clexane syringes at room temperature; do not put them in the fridge or freezer.
  • Used syringes: Keep used syringes in a hard plastic container (such as an empty detergent bottle) with a lid. You can take the container to your local pharmacy to be disposed of safely. Do not reuse syringes.

Image credit: VTE Matters, NZ 

Side effects

Like all medicines, Clexane can cause side effects, although not everyone gets them. 

Increased risk of bleeding

Clexane increases your risk of bleeding. You might bleed or bruise more easily while you are taking Clexane.

  • Be careful when shaving, clipping your fingernails, brushing and flossing your teeth, or playing sports. 
  • Don't get any new tattoos or piercings while you are taking Clexane or have any deep-tissue massage, as these things may cause bruising and bleeding.
  • Minor bleeding should usually stop on its own. If you have a fall or hurt your head or body, get medical attention immediately, even if you feel okay.
Signs of severe bleeding

If you have any of the following signs of bleeding, contact your doctor immediately or phone Healthline on 0800 611 116 for free 24 hour advice:

  • become pale, very weak and tired, or short of breath
  • any bleeding from your gums
  • cuts or nosebleeds that won’t stop
  • blood in your stools (poo) – black, tarry stools
  • blood in your urine (wee) – pink, red or brown-coloured urine
  • heavy periods (menstrual bleeding)
  • coughing up blood or vomit that looks like coffee grounds.


Clexane should not be taken with some other medications and herbal supplements, so always check with your doctor or pharmacist before starting Clexane or before starting any new medicines. Also, check with your pharmacist before taking:

  • over-the-counter anti-inflammatories such as diclofenac (eg, Voltaren Rapid), ibuprofen (eg, Nurofen) or naproxen (eg, Naprogesic)
  • herbal extracts such as garlic, ginkgo or ginseng.

Taking these together with Clexane may increase your risk of bleeding and should be avoided. 

Learn more

Clexane Medsafe, NZ
Enoxaparin NZ Formulary 


  1. Low molecular weight heparin use in primary care BPAC, NZ, 2009
  2. Enoxaparin Institute of Safe Medication Practice (ISMP)
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 27 Jul 2020