Tepezza stays in your system approximately 100 days after the last dose. This is calculated by looking at the average half-life of Tepezza which is 20 days. The half-life is the time it takes for 50% of a medicine to be eliminated from the body. Research has shown that it takes 4 to 5 half-lives for a medicine to be fully cleared from the body which calculates out to 80 to 100 days or 11 to 14 weeks for Tepezza.

Women of childbearing capability should use an effective form of birth control (contraception) before starting Tepezza, during treatment, and for at least 6 months after their last Tepezza dose. Experts also recommend males taking Tepezza should ensure their female partners are using effective birth control while they are taking it and for 6 months after the last dose.