The anatomy of a menstrual cup. Why are they shaped like that?

Rim

The rim is the top circle of the cup that is usually thicker and even protruding in a hoop skirt. The firmness of the cup can vary depending of its material, thickness and design. Some other cups are more “straight” as in more aligned with the body of the cup. Each have their pro and cons. A firm rim will pop open more easily once inside.

Air holes

Most menstrual cups have holes near the rim that are designed and placed strategically for the purpose of sealing the cup’s suction mechanism when placed properly in the vagina. Some cups have 1 or 2 while others have 3-4 holes. It depends on the shape of the bell and the specific design of the brand of menstrual cup. And again the holes or amount of holes in a menstrual cup may assist with better sealing of the cup or it may be a feature that someone does not like about a particular menstrual cup. It is all about preference and ease of use vs. effectiveness for the individual’s specific needs.

Most holes are round, Some are slanted (Ladycup) some are rectangled shaped (Miu cup), Some are tiny, some are bigger. Tinier holes would mean stronger suction so it’s up to you to decide which you prefer. If you are worried about the cup sliding down or having leaks, get a cup with small holes (Me Luna)

Please note: make sure to keep the holes clean which is easy but a bit tricky if they are tiny. You an use tiny brushes to clean those holes.

Some cups don’t have air holes like Formoonsacup because they have a completely different shape, more like a ball instead of a bell shape.

Body of the menstrual cup

The bottom of the cup can be smooth, have gripping rings or some other kind of pattern. Some also have smooth bottom without any stem.

As with all menstrual cup features, the smoothness or texture of the menstrual cup varies according to the design and brand of the cup. While some cups are developed to be all smooth from the rim, bell, and stem others have textures on the cup. Smooth cups are known to be comfortable, however some reviewers of various brands of menstrual cups note that having a smooth cup can cause issues with grasping, gripping the cup for the process of removal.

If you have a menstrual cup that possesses a texture, it is just the way the cup brand decided to design their brand. The texture can be helpful during the removal process and also be beneficial to a person. The writing or added markings on a menstrual cup is common, this is a branding feature that menstrual cups use to personally identify their cup. The writing or texture should not pose any harm or discomfort to the user, and is also just a matter of preference of what a menstrual cup brand offers.

Stem

The stem of the menstrual cup is located at the bottom of the bell so that it can be used to remove the menstrual cup out of the vagina. All menstrual cups offer different types of stem shapes that range in shape, firmness, size, and design including short and long stems, flat and round stems, and toggle and ring stems.  The most common stem featured on the top brands of menstrual cups is the flat stem, tab stem. It is like the name refers flat like a pull tab. This type of stem can be trimmed down and adjusted according to one’s needs. Another featured stem is the ball stem which is shaped like a solid or hollow ball, these stems are squishy and small. Then there is the ring stem which is shaped like a ring at the end of the cup and where you can pull it out by placing your fingers inside the hole and on the outside of the hole of the ring.

Menstrual cup stems are a fairly integral part of a cup design. The stem of a menstrual cup is designed to act as a guide, helping you locate your cup for easier removal. Unlike the string on the end of a tampon, the stem of a menstrual cup IS NOT designed to pull the cup out. Consistently pulling on the stem to break the cup suction or to remove the cup from the vaginal canal can lead to the stem weakening over time, or possibly even shearing off. The stem of a cup also helps provide reassurance to new users who may be worried that they won’t be able to reach their cup once it is inserted. For this reason, it is usually recommended not to trim the stem until you are confident in locating and removing your cup (think of the stem as a removal back up!).

Each stem feature boasts a different benefit to the user as some women prefer a flat tab stem to a ball stem and vice versa. It is a matter of preference of cup brand, unique build and circumstances that will determine which stem will work best for you.

Flat stem

The flat stem, tab stem often called pull tab. This type of stem can be trimmed down and adjusted according to one’s needs. If this stem type protrudes from the vagina, it may cause some discomfort. However, these stems are longer than other styles, making them more suitable for women who need a longer cup, or who would like the option to trim the stem to a length most suitable for them. These are the easiest stems to trim.

Ball stem

Another featured stem is the ball stem which is shaped like a solid or hollow ball,

Ring stem

Then there is the ring stem which is shaped like a ring at the end of the cup and where you can pull it out by placing your fingers inside the hole and on the outside of the hole of the ring. Great for beginners as it allows if you want to attach a cotton cord to feel.
We would not recommended trimming a ring stem, as it could make the base uncomfortable when removing (unless you can remove the entire stem without damaging the main body of the cup).

Grip body

Smooth cups are known to be comfortable, however some reviewers of various brands of menstrual cups note that having a smooth cup can cause issues with grasping, gripping the cup for the process of removal.

Softness

Yes, menstrual cups brands vary in their soft to firmness ratios, it is often referred as Shore which is a number of silicone softness. There are some menstrual cup brands that offer several sizes in different softness’s. This also makes the firmness, squishiness or softness of the cup vary according to the cup sizes and capacity. Again these variables are important for a person’s unique situation, needs, and preferences. Some women like softer cups for comfort, while others prefer the firmer cups that are easier to remove or insert.

Colors

Many brands of menstrual cups have begun manufacturing their cups in a variety of colors for your convenience and to add a special personal touch to their cups. Although the basic menstrual cups are still offered in the opaque, clear cup models- you can choose a brand that makes colored menstrual cups and order them in red, pink, purple, blue, black, green, orange, and much more. However, the colors available may vary by brand and make of the cup.

Material

Medical Grade Silicone

The majority of menstrual cups manufactured are made out of silicone, hor other special materials that are safe with health and medical uses. It is certain though that all devices used for period protection are conformed of the safest materials for intimate use.

TPE (Thermoplastic elastomers)

Medical grade silicone is a special material that is made to be bio-compatible (compatible with close use with skin) and that is non-toxic. This silicone is specifically designed and engineered to be used in the making of catheters, baby bottle nipples, and menstrual cups. The term medical grade refers to its patented safety and monitoring during the manufacturing process with accreditation, FDA approval, and medical certifications.

Rubber

The first menstrual cups were made out of rubber. The only cup that is still in Rubber is The Keeper.