As with other GLP-1 medications, tirzepatide is administered via a subcutaneous (under the skin) injection. While this can sound intimidating, it is something that patients tend to get used to fairly quickly.
The best places to administer the injection on the body are the upper thigh, upper arm or stomach. Several medications are delivered like this because it allows for a slow sustained rate of absorption and your body is able to continuously deliver the medication at a low dose.
In addition, some medications simply aren't absorbed well by the digestive tract or are destroyed by the acid and digestive enzymes in the stomach, which is why an injection is preferred as it bypasses this process.
For more details on subcutaneous injections, please refer to this link.