The menstrual cup is a flexible, bell-shaped device inserted into the vagina to collect menstrual fluid, offering a reusable alternative to traditional period products. Achieving optimal comfort and leak-free performance depends almost entirely on correct placement. The correct insertion depth is not a fixed measurement but a highly personalized target determined by individual anatomy and the specific location of the cervix. Finding this precise spot is the single most important step for ensuring the cup works effectively without causing discomfort.
Understanding the Anatomy: Cervix Height
The ideal resting place for a menstrual cup is directly related to the height of the cervix, the firm, rounded opening at the top of the vaginal canal. The cervix acts as the boundary between the vagina and the uterus and will feel similar to the tip of a nose or a firm, spongy doughnut shape when touched. Since the vaginal canal is a dynamic space, the cervix position can shift, often sitting lower during menstruation than at other times of the cycle.
To determine the required cup depth, a user must first measure their own cervix height, preferably during a period when the cup will be in use. This measurement is taken by inserting a clean finger into the vagina until the cervix is reached. The distance from the vaginal opening to the cervix is typically categorized as low, average, or high.
A low cervix is typically reached at the first knuckle, or less than 2 inches (5 cm), meaning the vaginal canal is relatively short and requires a shorter cup. An average cervix is found between the second and third knuckles, or about 2 to 3.5 inches (5-9 cm), which is compatible with most standard cup lengths. If the cervix cannot be reached, or only with the full length of the finger, it is considered a high cervix, allowing for a longer cup. The cup must sit below the cervix to collect flow and not press against it.
Achieving the Correct Insertion Depth
The correct depth for a menstrual cup is generally lower in the vaginal canal than where a tampon rests. Unlike a tampon, which is typically pushed high into the vaginal fornix near the cervix, the cup should sit just below the cervix, creating a seal against the vaginal walls. The goal is to position the cup so its rim is lower than the cervix opening, ensuring the menstrual flow drops directly into the cup. Inserting the cup too high may cause it to sit next to or surrounding the cervix, which often leads to leaks because the flow bypasses the collection area.
The cup should be inserted only as far as necessary to sit comfortably and fully open, without the user being able to feel it. For many users, this means the entire cup, including the stem, should be contained within the body. The stem, which is designed to aid in locating the cup for removal, should not be used as the depth guide itself. If the stem protrudes or causes irritation at the vaginal opening, it is an indication that the cup is too long for the user’s anatomy and the stem may need trimming.
Confirming Proper Placement and Seal
After the cup is inserted, it is necessary to ensure it has fully opened and created the suction seal against the vaginal walls. The cup is folded for insertion and must “pop” open inside the body to form a secure barrier. Users can gently rotate the cup or run a clean finger around the base of the cup to confirm its round shape and check for any folds or dents. A dimple or fold means the cup has not fully opened and the seal has not formed, which is a primary cause of leakage.
Once the cup feels fully rounded, a light tug on the stem can confirm the seal is present. If there is gentle resistance, the cup has successfully sealed and is correctly positioned to collect fluid. The proper suction is what keeps the cup in place and prevents it from leaking. If the cup slides down easily with a light tug, the seal is absent and the cup needs to be repositioned slightly higher or adjusted to open fully.
Troubleshooting Common Positioning Issues
Discomfort or leakage often signals an error in the cup’s depth or positioning relative to the cervix. If the cup is inserted too low, the stem or the base of the cup may poke or irritate the sensitive tissue around the vaginal entrance, causing pain when walking or sitting. This issue is resolved by pushing the cup slightly higher until the stem is no longer felt, or by trimming the stem if the cup is still too long for the vaginal canal.
Conversely, a cup inserted too high, especially in users with an average or high cervix, can migrate upward, making it difficult to reach the base for removal. Relaxing the pelvic floor muscles and bearing down, as if having a bowel movement, can help move the cup lower into a reachable position.
Leaks caused by placement errors usually happen when the cup is pushed past the cervix, allowing the flow to run down the side of the cup instead of into it. To correct this, the user must ensure the cup’s rim is positioned lower and fully encompasses the space directly beneath the cervix.