Disposable pen needles are sold separately from the pens and typically require a prescription. You attach them by screwing or snapping the needle onto the pen tip. Taking the needle out of its packaging, attaching it, removing the safety cap, and discarding the needle when finished can require nimble fingers and a good sense of touch to avoid accidental finger sticks. If this is a problem for you, ask your health care provider which needle may be easiest to use. Owen Mumford Unifine Pentips Plus have a built-in remover, for example. The NovoFine Autocover has a needle shield that automatically locks in place after injection. The BD AutoShield Duo conceals the front of the sharp before and after injection and covers the back of the sharp on removal from the pen.
It’s good practice to change your needle after each injection. Fresh, sharp needles may help reduce painful sensations.
Pen needles come in different lengths—including 4, 5, 6, 8, and 12.7 millimeters, shown below. Studies have shown that a shorter needle is effective for all body types.