The Smoon Guide

How to choose your menstrual panties?

Your flow, the fit you feel comfortable in, and your size: three questions, and you’ll know which style to choose. This guide answers them in order.

  1. 01Your feed
  2. 02Your fit
  3. 03Your size
View all pantiesI'm a beginner—where should I start?
Two women wearing black Smoon menstrual panties

12 h

daytime and nighttime protection

1 to 6 tampons

absorption level depending on the style, from thong to very heavy flow

XS to 5XL

and ages 10 to 16 for teenage girls

Step 01

Know your flow

Every woman has a different flow, and it changes depending on her cycle, age, contraception, exercise, or diet. It also varies from day to day: the second and third days are generally the heaviest.

Flow variation by day of menstruation
123 456 PERIOD DAYS

Light flow

Less than 30 ml per cycle

Beginning and end of your period, light everyday spotting

Absorbs the equivalent of1 tampon, 1 pad, or half a cup

Our stylesString Aphrodite

View the string

Medium flow

Between 30 and 50 ml per cycle

Fewer than one protection product every 3 hours

Absorbs the equivalent of2 tampons, 2 pads, or 1 cup

Our stylesSéléné, Ara (cotton), Amphitrite boyshorts, Calliope high-waisted, Comète, Karma

View medium-flow styles

Heavy flow

Between 50 and 80 ml per cycle

More than one pad every 3 hours

Absorbs the equivalent of4 tampons, 4 pads, or 2 menstrual cups

Our stylesArtemis, Aquilla (cotton), detachable Hemera, Leto boxer briefs

View heavy-flow styles

Very heavy flow

More than 80 ml per cycle

Very heavy periods, copper IUD

Absorbs the equivalent of6 tampons, 6 pads, or 3 menstrual cups

Our stylesHécate, 150 ml of absorption

View Hecate

Swipe left to see the other flow levels

The frequency and speed of your flow can saturate a pair of period underwear sooner than expected. When in doubt, choose the next higher absorbency level: heavy-flow underwear works perfectly well on a medium-flow day.

Step 02

Choose your cut

Choose the style that makes you feel most comfortable. All our models are seamless and invisible under clothing. What varies is the coverage and the available absorbency levels.

Briefs

Coverage

The classic cut, high-cut at the hips and buttocks. The widest choice in the range: microfiber or cotton, for women or teens.

Exists inModerate, heavy, very heavy

View the panties

Boyshorts

Coverage

More coverage at the hips and buttocks. The comfortable option for those who don’t like high-cut styles.

Exists inMedium

View the boyshorts

High-waisted

Coverage

More full-coverage, it rises to the navel, contouring your curves and keeping your tummy warm. Lightly shaping, perfect for defined waists.

Exists inMedium

View the high waist

Boxer

Coverage

The most absorbent style in the range, with an absorbent area that extends higher at the front and back. Ideal for nighttime and active days.

Exists inAbundant

View the boxer briefs

String

Coverage

High-cut, for the beginning and end of your period, or as a backup to a menstrual cup or tampon during the rest of your cycle.

Exists inLight

View the string

And the material?

Two ranges, two sensations. The same absorbent technology inside.

Microfiber

  • Second-skin effect, twice as thin as other period underwear.
  • Up to 12 hours of protection.
  • The widest choice of cuts, absorbency levels, and colors.
  • Slightly shaping when first worn, it softens from the first day.
View the microfiber range

Cotton

  • GOTS-certified cotton, soft and breathable, designed for sensitive skin.
  • Up to 8 hours of protection.
  • PFAS-free, tested under gynecological supervision.
  • Two styles: Ara for medium flow, Aquilla for heavy flow.
View the cotton range

Step 03

Find your size

Our styles run true to size: choose the size you usually wear. The absorbent area should fit snugly to follow all your movements and prevent leaks.

How to measure

  1. WaistAt the narrowest point of your torso, above the navel.
  2. HipsAt the fullest point, keeping the tape measure horizontal.
  3. Between two sizes?Go for the larger one.
  • A pair of underwear that is too tight is not more leakproof. The microfiber fabric is slightly shaping when first worn and softens from the very first day.
  • Our teen range is designed for body shapes whose hips have not yet developed pronounced curves. A girl who is already fully developed will often be more comfortable in adult XS or S: compare her measurements with both size charts.
SizeClothing sizeWaistHips
Women
XS3456-62 cm84-88 cm
S3662-68 cm88-92 cm
M3868-74 cm92-96 cm
L4074-80 cm96-100 cm
XL4280-86 cm100-104 cm
XXL4486-92 cm104-108 cm
3XL4692-98 cm108-112 cm
4XL4898-104 cm112-116 cm
5XL50104-110 cm116-120 cm
Teens
AgeHeightWaist circumferenceHip circumference
10/12 years142-150 cm58-64 cm76-82 cm
12/14 years150-158 cm64-70 cm82-86 cm
14/16 years158-166 cm70-76 cm86-90 cm

Swipe the table to see every measurement

View the full size guideHave a question? Write to us

First period

And for a teenage girl?

Same steps, dedicated range. Hébé for medium flow, Phébé for heavy flow, for ages 10/12 to 14/16. And One Size, whose stretch fabric adapts to the body’s changes from ages 10 to 16: one size, from the first period through the end of adolescence.

View teen pantiesEquiping my teen properly: the guide
  • ages 10–12, 12–14, 14–16Three sizes designed for hips that have not yet developed curves
  • 2 or 4 tamponsHébé for medium flows, Phébé for heavy flows
  • One SizeOne size for ages 10 to 16, thanks to the stretchy material

And what does that mean for you in practice?

Four common situations and what we recommend.

01

I'm just starting out

One medium-flow pair and one heavy-flow pair are enough to cover your entire cycle. And you have 60 days to try them at home, risk-free.

View beginner packs

02

My periods are heavy

Artémis by day, Léto or Hécate boxer shorts by night. The boxer shorts rise higher at the front and back, which is useful when sleeping on your side or stomach.

View the night panties

03

I prefer cotton

Ara for medium flow, Aquilla for heavy flow: GOTS-certified cotton, up to 8 hours of protection.

View the cotton range

04

End of period and light spotting

The Aphrodite thong, or medium-flow briefs worn alongside a cup on heavier-flow days.

View light-flow underwear

Your questions

How can I tell whether my flow is moderate or heavy?

A simple guideline: if you change your protection less than once every 3 hours, your flow is moderate. If it’s more frequent, your flow is heavy.

When in doubt, choose the next higher absorbency level: heavy-flow period underwear works perfectly well on a day with moderate flow, but the reverse is not true.

How many pairs of period underwear are needed for one cycle?

Count one pair of period underwear for each day of your period, plus one spare. With three to five pairs and a wash during your cycle, you’re all set.

The most effective approach is to combine two absorbency levels: heavy flow for the first few days, then medium flow.

Can I wear it at night?

Yes. Our styles provide up to 12 hours of protection. For nighttime, choose a heavy-flow style or the Léto boxer briefs, whose absorbent area extends higher in the front and back, which matters when lying down.

Microfiber or cotton?

Microfiber is the thinnest, with a second-skin feel and up to 12 hours of protection. It’s also the widest range in terms of cuts and colors.

GOTS-certified cotton is softer and more breathable, designed for sensitive skin, with up to 8 hours of protection. Two styles: Ara (medium flow) and Aquilla (heavy flow).

I'm between two sizes—which one should I choose?

Choose one size up. The absorbent area should remain snug against the body, but a panty that is too tight is not more leakproof. The microfiber fabric has a slight shaping effect when first worn and softens from the first day.

My daughter has started her first period: teen or adult range?

The teen range is designed for body shapes whose hips have not yet developed. If her figure is already more defined, compare her measurements with both size charts: adult XS or S often fits.

One Size fits ages 10 to 16 thanks to its stretch fabric, without needing to change size along the way.

What if I choose the wrong model?

You have 60 days to test, wear, and wash your period underwear. If it doesn’t suit you, you’ll be refunded: that’s our satisfied or refunded offer.

For a simple sizing issue, exchanges are free within 30 days for an unworn product.

How do I care for it?

Rinse it in cold water after wearing it, then wash it at 30°C on a delicate cycle, without fabric softener. Never tumble dry. All our care tips.

You know everything. All that’s left is to choose.

Flow, cut, size: you have all three answers. And if you’re still unsure, our customer service team can advise you.

View all pantiesContact us

And you have 60 days to test, wear, and wash your panties. Satisfied or your money back