Health Information and Tools > Patient Care Handouts >  How to Give an Anticoagulant (Blood Thinner) Shot: Care Instructions

Main Content

How to Give an Anticoagulant (Blood Thinner) Shot: Care Instructions

Injection sites, to either side and at least 5.centimetres (2 inches) from belly button.
Person giving self a shot, inserting needle straight into fold of skin on side of belly.


Some anticoagulant medicines are given as a shot (injection). Anticoagulants are also called blood thinners. Examples of these medicines include low-molecular-weight heparin and fondaparinux.

Blood thinners prevent new blood clots from forming and keep existing clots from getting larger. But they can also make you more likely to bleed. So it's important to take them safely.

At first, you may be nervous about giving yourself a shot. But soon, giving the shot will become routine.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse advice line (811 in most provinces and territories) if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

How do you safely inject an anticoagulant (blood thinner)?

Follow your doctor's instructions for how often to inject the medicine. Depending on what your doctor prescribed, you may give yourself a shot once or twice a day using prefilled syringes. Prefilled means that the syringes already have the medicine in them. Inject the medicine at the same time every day unless your doctor gives you other instructions.

Giving the shot

  1. Gather your prefilled syringe and an alcohol wipe or a cotton ball dipped in alcohol.
  2. Wash and dry your hands.
  3. Sit or lie in a position that lets you see your belly.
  4. Choose a site on the right or left side of your belly, at least 5 centimetres (2 inches) from your belly button.
  5. Clean the injection site with the alcohol wipe or cotton ball. Let it dry.
  6. Remove the cap from the needle.
  7. Hold the syringe like a pencil in one hand, keeping your fingers off the plunger. You may see an air bubble. It's okay. Unless your doctor tells you to, you don't have to remove the bubble.
  8. With your other hand, slightly pinch a fold of skin at the injection site between your fingers and thumb.
  9. Hold the syringe at a 90-degree angle to your skin so the needle is pointing straight at the injection site.
  10. Quickly push the needle all the way into the pinched-up fold of skin. Then push the plunger all the way in, so that the medicine empties out of the syringe. As you're giving the shot, keep holding the fold of skin so that you don't inject the medicine into muscle.
  11. Pull the needle straight out and let go of the skin.
  12. Point the needle away from you. Follow the manufacturer instructions for safely disposing of the needle and syringe. Don't use the same needle more than one time. Throw away the needle and the syringe in a safe place, such as a special container for needles.
  13. If you bleed a little, apply pressure over the shot area with your finger, a cotton ball, or a piece of gauze. To help avoid bruising, do not rub the area.
  14. Slightly change the spot where you give the shot each time you do it.

Being safe

  • Call your doctor if you think you are having a problem with your medicine.
  • Don't stop taking your medicine without talking to your doctor.
  • If you miss a dose, call your doctor. Your doctor can tell you exactly what to do so you do not take too much or too little blood thinner. Then you will be as safe as possible.
  • Check with your doctor or pharmacist before you use any other medicines, including prescription and over-the-counter medicines. Make sure your doctor knows all of the medicines and natural health products you take. Taking some medicines together can cause problems.
  • Try to avoid injuries to help prevent bleeding. For example, be careful when you are exercising.
  • Store your medicine at room temperature. Don't put it in the refrigerator or freezer.

Where can you learn more?

Go to

Enter M463 in the search box to learn more about "How to Give an Anticoagulant (Blood Thinner) Shot: Care Instructions".

Care instructions adapted under license by your healthcare professional. If you have questions about a medical condition or this instruction, always ask your healthcare professional. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.