Frequently Asked Questions
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FREE DELIVERY FOR ORDERS ABOVE £34 (in the UK) 😍 No customs duties 😍



About our underwear

How many pairs do I need to get through my entire period?

It's really all depends on how you use them: if, for example, you only want to use your panties at night and want to wash them every day, one pair of panties  for your whole cycle may be enough: you wash them in the morning and put them back on in the evening. If, on the other hand, you want to wear yours night and day and wash them all at the same  time and in the same wash at the end of your period, you will need between 8 and 10 pairs, depending on the duration of your period. If you're somewhere in the middle and are able to do a load of washing halfway through your period, 4 to 5 pairs will be enough.

You can check out all our styles by clicking here.

How do I choose the right size underwear for me?

To make sure you choose the right size, measure around your hips where they are the widest (usually at the hip bones) and use to the chart below to guide you. If you are between 2 sizes, we recommend going for the smaller size:

Hip measurement:

76 / 78 cm  ⇒ 10/11 yrs

79 / 81 cm  ⇒ XXS

82 / 86  cm ⇒ XS

87 / 91 cm ⇒ S

92 / 96 cm ⇒  M

97 / 101 cm ⇒  L

102 / 106 cm ⇒ XL

107 / 111 cm ⇒  2XL

112/116 cm ⇒ 3XL

117 /121 cm ⇒ 4XL

Published: 09 / 08 / 2019

Why is it cheaper to use Sisters Republic absorbent underwear than regular protection?

A woman experiences an average of 450 menstrual cycles during her lifetime and will spend €8,000 on menstrual products from puberty to menopause (according to a Huffington Post study), so this budget is far from negligible for women. Sisters Republic panties can help you reduce these costs: if you buy a 7-pack of panties, your Sisters Republic panties will only cost you €25.60 each and last 4-5 years. No more $4-$5 worth of tampons and sanitary pads being thrown away every month! And that's just as much less garbage for our beautiful planet.So Sisters Republic panties are both economical and  environmentally friendly.

You can check out all of our styles by clicking here.

Can I use my Sister Republic underwear while doing sport?

Yes, your Sisters Republic underwear is ideal for protection during sport because, unlike sanitary pads which can slip or bunch up, they stay securely in place. All of our models are perfectly suited for sports, but we particularly recommend the boyshorts because they provide fuller coverage and will move with your body.

You can check out all our styles by clicking here.

Do I need to use one or more pairs a day?

If you're using the Sisters Republic underwear for your flow ("Light" for a light flow, "Medium" for a medium flow, or "Super" for a heavy flow), you can wear your underwear for up to 12 hours and change at night, or use another form of period protection.

However, if you are using "Light" absorption with a medium or heavy flow or "Medium" absorption for heavy flow, you will likely need to change your underwear after 3 to 6 hours to make sure you stay feeling dry. The table below summarises the number of hours you should be able to wear your underwear for maximum comfort, but the best thing is still to rely on your senses and to change your underwear as soon as you start to feel any dampness.

If you are using your period underwear for the first time, we suggest that you to test them at home in order to get an idea of how they work with your flow.

If your flow is very heavy, we advise you wear our underwear in addition to your other period protection.

You can check out all of our styles by clicking here.

How long can I wait to wash my Sisters Republic underwear after I rinse them? 

If you rinse out your period underwear with cold water right after use (make sure the water runs clear), you can wait until you put in your next load of washing to wash them.

Don't worry if they've dried out in the meantime!

Is Sisters Republic absorbent underwear really hygienic and odour-free?

The fabric used in the manufacture of our Sisters Republic panties is antibacterial and therefore anti-odour. In addition, it is an ultra-absorbent fabric that immediately redirects the liquid to the heart of the absorbent part so that the surface is always dry and therefore limits the feeling of dampness and odour.

You can take a look at our panty models by clicking here.

How do I choose between the three different levels of absorption, "Light", "Medium" and "Super"?

"Light" absorption is great for the end of your period or if you generally have a very light flow, which is often the case if you have a hormonal IUD or take certain contraceptive pills. It will allow you to feel protected and offer ultimate comfort with a thickness at the gusset of just 1 mm.

"Medium" absorption is ideal for the 2nd or 3rd day of menstruation, as it offers good absorption without being to thick.

Lastly, "Super" absorption is perfect for the beginning of your period, at night or for those with a heavier flow. They are thicker at the gusset than other levels but are still less than 3 mm, which is definitely slimmer than a pad, whilst still offering maximum absorbency.

Feel free to mix and match absorbency to get the best protection and comfort for your period.

Can I use Sisters Republic underwear in anticipation of my period or before my first period?

Yes of course, Sisters Republic period underwear is pretty, comfortable to wear and very thin (between 1.5 and 3 mm), so nothing like the thickness of a sanitary towel. That means you can wear whenever you like, without discomfort and without worrying that they are noticeable to you or anyone else. They are a great option for the days leading up to the start of your period to help prepare you for any surprises.

Can I swim in my Sisters Republic absorbent underwear?

We don't recommend you swim in your Sisters Republic underwear as they are just not made for it, and we can't guarantee that our absorption technology will work underwater.

You can take a look at all our styles by clicking here.

Does the absorbent part of the underwear come up high enough?

The absorbent part of our panties is not only in the gusset, it also comes up the front and goes very high at the back to maximize absorption and avoid leaks.

The absorbent part of the Sidonie bikini actually covers the area  from the top of the front to the top of the back.

- On our "Colette", "Bloody Sunday", "Tonight" and "Do not enter" styles, the absorbent part covers  from the top of the back side of the underwear,  goes all the way down and goes 18 cm up the front (based on size M)

-** On the Ginger boy shorts**: the absorbent part covers from the top of the back side, goes all the way down and goes 18 cm at the front (based on size M).

Does the underwear absorb clots that may sometimes be present in the blood?

About the blood clots that can occur during menstruation in some people. As these are non-fluid substances, the panty will unfortunately not be able to absorb them completely.

Can I use a Sisters Republic underwear for after giving birth?

Yes, the Sisters Republic period underwear can help you out postpartum. However, every woman is different and the amount of bleeding at this time can be particularly heavy, so we recommend that you opt for the "Super" absorption and  use them alongside other protection for the first few days. This way you can get the best possible leakage protection during that tricky time. You can use them on their own for your next 'normal' period.

What is the maximum amount of flow Sisters Republic Absorbent underwear can handle?

No matter the style of underwear, if you go for a pair of Sisters Republic period underwear with "Super" absorption, they will absorb up to 20ml - the equivalent of 3 tampons - or up to 12 hours of peace of mind if you have a normal period.

Can I use my Sisters Republic absorbent underwear instead of or in addition to my usual protection?

You can do either! If some days your flow is really heavy - like at the beginning of your period - and you often have accidents (leaks and stains) when using other protection (tampons, sanitary towels, the cup...), we recommended using your Sisters Republic underwear as an extra layer of protection. This way, you'll have peace of mind and will be sure to be 100% leak-proof.

If your flow is more 'normal',  your Sisters Republic period underwear will work great as a replacement for your other period protection, just make sure you choose the right level of absorbency ("Light", "Medium", "Super") based on your flow (light, medium, heavy). We also recommend sticking to the suggested change times, or, better yet, relying on your senses and changing your underwear if you start to feel any dampness.

Can I use Sisters Republic underwear if I'm prone to yeast infections, allergies, or other irritations?

If you are prone to fungal infection, allergies or other irritations, menstrual panties are certainly the most suitable periodic protection for you because they are non-intrusive and non-irritating.

In addition, our underwear doesn't rub against you and the gusset is made from cotton, unlike sanitary towels which are mostly plastic.

About periods

What to eat during your period?

If, like 80% of women, you suffer from painful periods (headaches, cramps or tender breasts), you make like to know that these symptoms are the result of an inflammation linked to a substance called C-reactive Protein, which is abundantly present in your body around the time of your period.

By choosing a diet with anti-inflammatory properties, based on fibre and omega-3s such as fatty fish (salmon, sardines, mackerel, or herring) or rapeseed or walnut oils, you can reduce the severity of your symptoms. For women who are at risk of anaemia, opt for iron-rich foods (such as red meat, poultry, offal, fish and seafood, cumin, etc.) during this period.

What is period blood made of? Why is it sometimes darker than regular blood?

Menstrual blood is composed of lymph, water, red blood cells and endometrial cells (the lining of the uterus) - pretty standard. If you notice the blood is sometimes a little browner at the end of your cycle, that is usually because it took longer to leave the uterus. The longer it stays in the body, the darker it can become.

Is it normal to have heavy or painful periods?

If you have really heavy and/or very painful periods, it may be necessary to consult a gynaecologist as this may be a sign of a dysfunction or a condition such as endometriosis. The uterine contractions triggered during menstruation are often painful, but if you are at the point where you can no longer get up during this period, you should consult a gynaecologist.

How much does a woman spend on average on menstruation throughout her life?

 According to a Huffington Post study, a woman spends an average of £8,000 on hygiene products throughout her lifetime, which includes around 450 menstrual cycles, spanning from puberty to menopause. As you can see, these aren't small sums!

Sisters Republic can help you reduce these costs: buying a multi-pack of Sisters Republic underwear can cost as little as £25.60 per pair and will last 4-5 years, or much longer if you take good care of them. No more spending £4-5 on tampons, sanitary pads and panty liners that are just thrown away every month! And not to mention the impact on the planet. If you are looking for a good value, environmentally friendly solution for your period protection, Sisters Republic underwear is for you!

You can check out all our styles by clicking here. According to a Huffington Post study, a woman spends an average of £8,000 on hygiene products throughout her lifetime, which includes around 450 menstrual cycles, spanning from puberty to menopause. As you can see, these aren't small sums!

Sisters Republic can help you reduce these costs: buying a multi-pack of Sisters Republic underwear can cost as little as £25.60 per pair and will last 4-5 years, or much longer if you take good care of them. No more spending £4-5 on tampons, sanitary pads and panty liners that are just thrown away every month! And not to mention the impact on the planet. If you are looking for a good value, environmentally friendly solution for your period protection, Sisters Republic underwear is for you!

You can check out all our styles by clicking here.

Can you get pregnant during your period?

It's amazing, but the answer is yes! The probability is very low but it exists. Some cycles are very short, sometimes only 21 days, so ovulation occurs earlier. Given that we know that sperm can fertilize between 2 and 5 days after unprotected intercourse, then we understand that yes, indeed, you can get pregnant during your period.

What is the environmental impact of sanitary protection in the world?

What is the worldwide environmental impact of menstrual products? Approximately 100 billion pads, tampons and sanitary towels are thrown out each year (source: The Telegraph). When you consider that a tampon takes 6 months to biodegrade and that pads and applicators can remain in landfills for centuries, you can understand why it's important to opt for washable and reusable options, like period underwear.

You can check out all our styles by clicking here.

How many times in her life does a woman get her period?

Between puberty and menopause, a woman will have an average of 450 menstrual cycles, which equates to more than 2,000 days of menstrual bleeding! That's a lot and that's why it's so important to find the right period protection, providing both comfort and effectiveness.

You can check out all our styles by clicking here.

About your orders

Can I return or exchange one or more items from my order?

How much does delivery cost?

Free delivery in the United Kingdom for orders over £34.

Free delivery in the Metropolitan France and Germany for orders over €40.
Free delivery in Spain for orders over €90.

Here are our delivery costs:

Free in the United Kingdom from £"4. Orders less than £34: £6.10

For other countries:
Free in Metropolitan France from €40. Metropolitan France (orders less than €40): €4.98.
Free in Germany from €40. Germany (orders less than €40): €6.10
Free delivery in Spain for orders over €90 (orders less than €90): €8.90
Belgium, Luxembourg, Netherlands, Liechtenstein, Switzerland: €6.10
Other EU countries: €8.90
Rest of the world: €18.35

We deliver worldwide!

Sisters Republic is not responsible and cannot be held responsible or liable for any customs duties that may be applied in your country of delivery.

Where can I buy Sisters Republic period underwear?

The Sisters Republic panties are currently only available at

What countries do you deliver to?

We deliver to the countries listed below:

Metropolitan France, Germany, Belgium, Luxembourg, Netherlands, Spain, Italy, Portugal, Great Britain, Poland, Hungary, Denmark, Switzerland.

Delivery is free in Metropolitan France for orders over €40.

For other countries:

Metropolitan France (orders less than €40): €4.65

Germany, Belgium, Luxembourg, Netherlands: €7.95

Spain, Italy, Portugal, Great Britain: €9.50

Poland, Hungary, Denmark, Switzerland: €16.45

Do your prices include all taxes and customs duties for international deliveries ?

Our prices do not include any local taxes, customs duties, brokerage fees and VAT or any other additional charges you may have to pay for international delivery. Please make sure you have calculated all these charges correctly as when your order arrives you will be asked to pay them (and we will not be able to refund them if you change your mind).

Is it possible to change my order after payment?

Your order is processed as soon as you validate it on our site so that you can receive it as soon as possible.

So it's not possible to modify it but if you contact as soon as possible to request a cancellation, if your order has not yet been taken care of by our logistics partner, we will be able to refund you, and you will be able to reorder  your preferred item.

How can I leave a review?

To leave us a review, simply send your review by email to or leave a review on our Facebook page.

Can I exchange or return part of a multi-pack?

Yes, you can return any item from a multi-pack (with its individual packaging).

If you'd like to know more about an exchange or refund, please check out the following page:

How do I get a partnership as a web influencer?

If you are interested in a partnership with us, please contact us at lauren@sistersrepublic. We're looking forward to hearing from you! Don't forget, you can check out all of our styles by clicking here.

Where do I enter my discount code?

If you have a valid discount code, enter it just before paying for the discount to be applied.

What payment methods and currencies do you accept?

We accept payment in euros by credit card or PayPal.

You can take a look at our different period underwear styles by clicking here.

How is my personal data stored and protected?

To find out how we use your personal data, you can read our Privacy Policy and our Privacy and Cookie Policy  here.

How can I track the progress of my order and/or package after it has been sent? 

You will receive an email as soon as your order is confirmed and another when it is dispatched by us. If you have not received a confirmation email after placing an order on our site, check your junk mail and, if necessary, send an email to

About us

Who are we?

The Sisters Republic story

Sisters Republic is the brainchild of Stéphanie Leone and Elie-Jo Elmaleh, two entrepreneurs conscious of the environment and committed to more responsible consumption.

What are the mission and values of Sisters Republic?

We believe that a woman's body should never be taboo. We believe that it is possible to smile at everything and feel good, even during your period. We believe in  being respectful to your body and the environment in the quest for a healthier life and future. We believe that period protection shouldn't be complicated or unpleasant to use, and it definitely shouldn't be toxic to your health!

That's why we created Sisters Republic.

Our mission: to bring confidence, softness and lightness to women on their period thanks to protective underwear that is both comfortable and pretty like your regular underwear but also 100% effective, environmentally friendly and long-lasting.


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Free delivery on orders over £34

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Satisfied or refunded for 60 days

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