Kesimpta is a brand-name subcutaneous injection prescribed for certain forms of multiple sclerosis (MS). Kesimpta begins working right away, but it may take some time for you to notice relief in your symptoms.

Kesimpta is a monoclonal antibody and belongs to a class of drugs called CD20-directed cytolytic antibody. It is not a chemotherapy drug. Because Kesimpta is a subcutaneous injection (an injection given under the skin), typically, a healthcare professional will administer your first dose. Then, they will teach you or a caregiver how to administer the drug at home.

Read on to learn more about when Kesimpta takes to work, how long the drug stays in your system, and more.

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Kesimpta starts working after receiving your first dose of the drug. However, you may not notice relief in your MS symptoms for at least a few weeks. The effects of the drug may vary from one person to another.

In clinical trials, many people noticed a decrease in their MS symptoms within 2 weeks of starting treatment. However, others experienced benefits after 12 weeks. People who took Kesimpta had fewer relapses, a slower rate of disease progression, and a reduction in active lesions.

Since Kesimpta may take some time to work, it’s important to continue using the drug as your doctor prescribes. Your doctor will monitor your progress to determine whether the drug is helping to manage your symptoms.

Researchers don’t fully understand how Kesimpta works to treat MS. However, they believe the drug targets a specific protein present on your lymphocytes (a type of immune cell) known as CD20. After attaching to your lymphocytes, Kesimpta kills these immune cells, which may reduce the activity of your immune system.

Since MS involves an overactive immune system that can damage your nerves, decreasing immune system activity may slow down the progression of your MS and reduce relapses.

The half-life of Kesimpta is approximately 16 days. This means that it takes about 16 days to remove half of the medication from your body. However, other factors may affect how long the drug stays in your system.

If you have questions about how long Kesimpta stays in your system, talk with your doctor or pharmacist.

Kesimpta may help relieve MS symptoms, decrease relapses, and lessen the rate of progression. If you want to learn more about Kesimpta as a potential treatment option for you, be sure to talk with your doctor about what to expect when using it. Together, you and your doctor can decide if Kesimpta is right for you.