How Butterfly Needles Are Used for Blood Draws and Simple IVs

Nurse getting ready to insert butterfly needle into patient's arm
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During treatment for breast cancer, you'll get to know a lot of winged needles. These are often called butterfly needles. They are used for phlebotomy (blood sample collection) and to give you intravenous drugs or saline fluid. Chemotherapy can be hard on your veins, making them fragile, hard to find, and hard to access with a needle. That's where a very slender needle, held by a very experienced and compassionate phlebotomist (blood draw technician or nurse) comes to the rescue.

The Basics

A butterfly needle is a short, straight, very thin hollow needle that is usually held by its wings and attached to a slender, flexible catheter line. At the far end of the line is a connector that will attach to a collection bottle, vacuum tube holder, a syringe, or to tubing from an infusion pump or transfusion bag. The needle may have a safety device that will slide over it and lock after it is used, to help prevent needlestick injuries.

At first glance, these may resemble Huber needles, which are also winged, but butterfly needles are not designed to be used with implanted ports. Huber needles are needed for that.

Phlebotomists use butterfly needles for blood draws to get your complete blood count (CBC). These very thin needles are good for patients with small or spastic (rolling) veins; children, adult hand or foot veins, scalp veins, and elderly people.


Butterfly needles may be used in several settings. These simple IV needles can be used for blood collection, a chemo infusion, to give antibiotics, pain medications, or saline fluid.

Butterfly needles may be left in place for a few hours or over five to seven days if properly secured. These needles come in several lengths and gauges, with color-coded wings, needle guards, and in some models, retractable needles.

Butterfly needles are inserted through your skin into a vein at a very low angle. The fastest needle stick is the least painless unless you move around when you see the needle coming. The advantages of using a butterfly needle are that it can be very precisely placed and it is able to enter smaller, more superficial veins.

If you are needle-phobic, concentrate on taking a deep breath when it is time to get stuck; this can help distract you when the needle makes contact with your skin. After use, the needles should be safely disposed of, along with medical waste. You will have a bandage over your needle puncture after treatment; be sure to keep it on 15-30 minutes after your infusion, to keep the area clean and prevent leaks.

You may still get butterflies in your stomach if you hate needle sticks, but butterfly needles are useful, less painful, and enable you to get the testing and treatments that you need during your journey through breast cancer. Don't fear the butterfly.

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Article Sources
  • Advances in technology improving safety and efficiency in a blood sample draw. Ana Stankovic. Medical Laboratory Observer 2011 Jan; 43(1):18, 20.
  • Challenges of the oncology draw. Karen Lynn. Medical Laboratory Observer, January 1, 2011.