There are dozens of menstrual cups on the market, and the best one isn't the most expensive or the most popular: it's the one that fits your body and your flow. This guide walks you through the six questions that decide which menstrual cup is right for you, and how to choose between the two Lunette sizes.
Quick answer: Choose a menstrual cup by your flow first, then your cervix height and pelvic floor. With Lunette, Size 1 (25 ml, softer) suits a light to medium flow, a low cervix, a strong pelvic floor, a sensitive bladder or teens. Size 2 (30 ml, firmer) suits a heavier flow or a high cervix. If you're unsure, start with Size 1.
1. How heavy is your flow?
Your flow is the most important question, and it's the one Lunette uses to guide most people. A cup collects blood rather than absorbing it, so its capacity decides how often you empty it.
- Lighter flow: you change a low or regular tampon or pad two or three times a day. Size 1 holds 25 ml.
- Moderate to heavy flow: you change a regular or high-absorbency tampon or pad every three to four hours. Size 2 holds 30 ml, so you can go a little longer between emptying.
| Lunette Size 1 | Lunette Size 2 | |
|---|---|---|
| Capacity | 25 ml | 30 ml |
| Diameter | 41 mm | 46 mm |
| Stem | 25 mm | 20 mm |
| Silicone | Softer | Firmer |
| Measuring lines | 5 ml and 13.5 ml | 7.5 ml and 15 ml |
| Usually best for | Light to medium flow, low cervix, strong pelvic floor, sensitive bladder, teens | Medium to heavy flow, high cervix |
Most people empty a Lunette cup two to four times a day. You can wear it for up to 12 hours, including overnight; local rules differ, and in Germany and Australia the limit is 8 hours (France: 6 to 8 hours, no overnight use).
2. Where does your cervix sit?
Your cervix is the lower end of your uterus, at the top of your vagina. Its height decides how much room the cup has.
- Low cervix (easy to reach with a finger): a shorter, smaller cup sits more comfortably, so Size 1 is usually the better fit.
- High cervix (hard to reach, or you can't feel it at all): the cup may move up, so a cup that's easy to reach matters. Lunette suggests Size 2 here.
Your cervix moves during your cycle and is often lowest on your heaviest days, so check it during your period. Read more in high cervix, low cervix and your menstrual cup.
3. How strong is your pelvic floor?
Your pelvic floor muscles hold the cup in place.
- Strong or tight pelvic floor (for example, if you do a lot of sport, yoga or pilates): a firmer, wider cup can feel like pressure. Lunette recommends Size 1.
- Weaker pelvic floor (for example, after giving birth): the muscles hold the cup less firmly, so it may move, slip down or leak. Pelvic floor (Kegel) exercises help, and wearing a cup trains these muscles too, because they actively hold it.
We cover this in more depth in menstrual cups and your pelvic floor.
4. Do you have a sensitive bladder?
Some people feel the cup pressing towards the bladder, especially when sitting or exercising. Softer silicone adapts to your body more easily, so if you know your bladder is sensitive, Size 1 is usually more comfortable.
5. Is this your first cup, or are you a teen?
Lunette often recommends Size 1 for first-time users and teens: it's slightly smaller and softer, which makes it easier to insert and remove while you learn. Still, choose mainly by flow and comfort. Most people get the hang of a cup within two to three cycles, and our step-by-step guide on how to use a menstrual cup helps with folds and placement.
Have you given birth? You can use either size. Childbirth can change your cervix position and your flow, so look at both again; see wearing a menstrual cup after pregnancy.
6. What is the cup made of?
A cup sits inside your body for hours, so the material matters as much as the size. Look for medical-grade silicone from a brand that tells you where and how the cup is made. The Lunette cup is made in Finland from 100% medical-grade silicone and lasts up to 10 years with proper care. For what to avoid, read how to spot a good period cup.
How to choose between Lunette Size 1 and Size 2
Put your answers together:
- Mostly light to medium flow, low cervix, strong pelvic floor, sensitive bladder or first cup? Choose Size 1.
- Heavier flow or a high cervix? Choose Size 2.
- A mix of both? Go by your flow and comfort. Many people with a mix start with Size 1, because it's softer and easier to learn with.
Still not sure? Our menstrual cup size guide has the full size comparison. And if your first size clearly doesn't work after a fair try of two to three cycles, Lunette refunds it or sends you the other size.
Ready? Choose your Lunette menstrual cup in Size 1 or Size 2.
Choosing a menstrual cup: frequently asked questions
How do I know which menstrual cup size I need?
Start with your flow. A light to medium flow usually suits Lunette Size 1 (25 ml), a heavier flow Size 2 (30 ml). Then check your cervix: a low cervix points to Size 1, a high cervix to Size 2. If the signs are mixed, Size 1 is the easier cup to start with.
Is a softer or a firmer menstrual cup better?
Neither is better for everyone. A softer cup, like Lunette Size 1, is gentler if you have a strong pelvic floor or a sensitive bladder, because it adapts to your body. Size 2 is firmer and holds more, which suits a heavier flow. Choose the firmness that suits your body, not the one with the most reviews.
Which menstrual cup is best for beginners?
Many first-time users find a smaller, softer cup easier to insert and remove while they learn, which is why Lunette often suggests Size 1. Expect a learning curve of two to three cycles. If your first size clearly doesn't work after that, Lunette refunds it or sends the other size.
Does my age matter when choosing a menstrual cup?
Less than most people think. Lunette recommends choosing mainly by flow and comfort. Teens and young users often prefer the smaller Size 1 because it's easier to get in and out. After childbirth, look again at your cervix position and flow.
How long does a menstrual cup last?
With proper care, a Lunette cup lasts up to 10 years. Clean it every time you empty it. Boil 5 minutes before first use and after each completed cycle. Replace it if it tears, gets holes or isn't in good condition anymore.
