Neulasta (generic: pegfilgrastim) is a prescription medication used to reduce the risk of infection in people receiving strong chemotherapy that decreases the number of infection-fighting white blood cells known as neutrophils. Neulasta belongs to a group of drugs called colony stimulating factors, which stimulate the body to produce neutrophils.

This medication comes in an injectable form and injected just under the skin, usually once per chemotherapy cycle.

Common side effects of Neulasta include muscle and bone pain.