How deep (in cm) should medication be inserted into the posterior fornix?

For medication insertion into the posterior fornix, the drug should generally be placed about 10 to 12 centimeters from the vaginal opening.

The posterior fornix refers to the recess between the cervix and the posterior wall of the vagina. It is a deep anatomical space located near the rectouterine pouch—the lowest portion of the female peritoneal cavity—and is commonly used for procedures such as puncture or drainage. When administering medication through the vagina, patients should first clean the external genitalia and hands thoroughly, then use their fingers to gently insert the medication along the vaginal canal until reaching the fornix. Inserting the medication approximately 10 to 12 centimeters from the vaginal opening will typically position it correctly within the fornix. If using capsule-type medications, they can be directly inserted into the vagina with a gloved finger. For vaginal suppositories, an applicator can be used for accurate placement.

Patients are advised to seek treatment at a reputable medical facility and follow a physician's guidance when using medication, avoiding self-medication that may lead to adverse effects. Additionally, patients may choose to lie on their side or elevate their hips during administration to minimize leakage of the medication.