OverviewDosageSide EffectsInteractionsHalf-Life

Anyone taking Neulasta (pegfilgrastim) can benefit from knowing more about it, including how long Neulasta stays in your system. Experts state the following information regarding Neulasta half-life:

Mean effective half-life: 15 to 80 hours after SC injection (depending upon the patients age)

Mean accumulation ratio: Studies indicate little to no accumulation

Terminal elimination half-life: 30.1 ± 38.2 hours (age group: 0 to 5 years),  20.2 ± 11.3 hours (age group: 6 to 11 years), 21.2 ± 16.0 hours (age group: 12 to 21 years)

The absolute bioavailability of filgrastim is roughly 60% to 70% when administered subcutaneously, according to the FDA. Neulasta (pegfilgrastim) is the PEGylated form of filgrastim, and experts estimate that it has a lower bioavailability than filgrastim. Experts are not 100% sure if the body breaks pegfilgrastim into metabolites, although serum levels of this drug begin to decrease after neutrophil (granulocyte) levels reach a normal level. Experts note that the renal (kidney) clearance of pegfilgrastim is lower than that of filgrastim.


What is the half-life of Neulasta?

According to the FDA, Neulasta has a half-life of 15 to 80 hours after subcutaneous injection.

How long does Neulasta stay in your system?

Pegfilgrastim has a half-life of 15 to 80 hours. Since it takes roughly 5.5 half-lives for the body to eliminate substances, that means it will take approximately 82.5 hours (3.4 days) to 440 hours (18.3 days) for the body to nearly or completely eliminate Neulasta.

Patients should not take Neulasta 14 days (2 weeks) before their next round of chemotherapy.

What does Neulasta do to your body?

Neulasta helps the body make more neuphatils, a type of white blood cell. The boost in these cells helps strengthen patients’ immune systems so they can fight complications like febrile neutropenia. 

How long do the side effects of the Neulasta shot last?

The body usually does not need more than 14 days to clear Neulasta.

How long does it take for chemotherapy to get out of your system?

The answer to this question can vary based on several factors. However, the actual drugs used for chemotherapy typically leave the body within a few hours after the treatment itself. Just because these chemicals leave the body, though, doesn’t mean patients still can’t feel their effects. In fact, it could take several months for the patient to recover from chemotherapy. It is completely dependent upon which chemotherapy regimen a patient is receiving.

Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.

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