Everything You Ever Wanted to Know About Period Underwear

Have you tried period panties yet?? In this informative post, I share literally everything you ever wanted to know about period underwear! From where to buy period underwear to how to care for period undies to odors, heavy flow, and more — it’s all here!

This post is NOT sponsored by SheThinx in any way.

For the last couple of months, my daughter and I have been trying out period underwear.

I was a skeptic at first.

Would they actually catch blood flow? Would they leak? Were they another snazzy new menstrual product claiming to alleviate all our period woes only to over-promise and under-deliver?

Now that 2 women in our family have tried out period underwear (we’re using SheThinx <– click here to save $10 on your first order and learn my picks!), I’m ready to share about them.

WE’RE IN LOVE, y’all.

I ditched disposable period products for reusable stuff over a decade ago.

I’ve been using a menstrual cup since before cups were cool. My daughter has used washable pads for all of her 3 years of menstruating. And, I started using pads while I was healing the pelvic floor dysfunction that made my cup uncomfortable.

This isn’t my first rodeo with reusable menstrual products!

I thought the menstrual cup was the best thing to ever happen to my period… until now. I’m a total period underwear convert!

In this post, I hope to share everything you ever wanted to know about period underwear.

I reached out to my Instagram audience for period underwear questions, which I’ve included here.

First, why period underwear?

My goal with this post is to at least get you curious enough about period panties to try them if you never have. I absolutely will never recommend a product to you that I have not tried and fallen in love with myself.

In this case, my daughter and I both are ready to ditch the menstrual cups and cloth pads for our period undies! We really love them THAT much! If you’ve been wanting to try period undies anyway, use this link to save $10 on your first SheThinx period underwear purchase!

For the thousands of years, people have been trying to invent a gamut of menstrual products — from papyrus used as tampons in Ancient Egypt to the first disposable pad in the 1880s to menstrual cups circa 2008.

The teen magazines I read in the late 1990s taught me to be terrified of leaks, soiled underwear, blood-stained pants, and spotty sheets. Very early in my menstruation, I learned that periods were meant to be hidden. I was taught that we didn’t talk about “those things”, especially in front of men.

And yet, our bathroom cabinets were full of boxes of disposable pads and tampons — each promising to catch and conceal blood better than the rest.

I think the better question is WHY NOT period underwear?

9 Reasons to Try Period Underwear

Most (not all) of us wear panties anyway. Doesn’t it make sense to have washable, reusable panties that are designed to collect our period blood instead of having to constantly spend our money on menstrual contraptions — the majority of which are toxic to our bodies and also add to our Earth’s trash burden?

The average menstruating person will use over 11,000 disposable period products during their lifetime — all of which end up in landfills, oceans, and rivers. Period underwear are an up-front investment that save us money over time.

Not only are period underwear insanely comfortable and efficient, they’re also kinder to our planet and to our bodies! Here are 9 reasons to try period underwear:

no more discomfort from pads, tampons, or cups
no toxic chemicals going “up there”
they’re earth-friendly by reducing waste
they can be worn as long as or longer than tampons, cups, and pads
period underwear look and feel like “normal” undies
many bleeders report decreased cramping when they stop using insertable products
no risk of toxic shock syndrome
save money in the long run because you aren’t continuously buying disposable products
better for your plumbing and septic system

Do they actually hold blood?

YES! A thousand yesses!

Shocked? Great, I was, too.

I was surprised by how much blood period underwear can hold.

On the first 2 days of my cycle, I wear the Organic Super Cotton Brief (which holds the equivalent of 4 tampons) and nothing else.

(I do not wear the same pair for 2 days, just as I would not wear a pair of non-period underwear for 2 days straight. I change at night into a clean pair and wash the pair I bled in to have it for the following day.)

Days 1 and 2 are my heaviest days, and I get away with wearing the same pair of period undies for 8 to 10 hours before changing.

Different styles hold different amounts of blood. For example:

Organic Super Cotton Brief (super absorbency) = 4 regular tampons or 1.25 cups or 2 regular pads
Organic Cotton Brief (moderate absorbency) = 2 regular tampons or 3/4ths of a cup or 1 regular pad
Boyshorts (heavy absorbency) = 3 regular tampons or 1 cup or 1-1/2 regular pads
Cheeky (light absorbency) = 1 regular tampon or 1/4th of a cup or 1/2 of a regular pad

You know your period best, so you can choose a pair of period underwear for each phase of your cycle.

For me, that’s the Organic Super Cotton Brief for days 1 and 2, the Organic Cotton Brief for days 3 and 4, and the Organic Cotton Bikini for the rest. (Click here to see my picks + save $10 on your first SheThinx order!)

If you like thongs, cheeky panties, boyshorts, hiphuggers, or high-waist panties, there’s a style and an absorbency level for your period!

So, period panties aren’t just fancy panties worn for comfort during your period?

Correct. Although, I totally wish all my underwear were the comfort and fit and quality of my SheThinx period underwear. No lie.

My favorite style — the cotton brief — is uh-mazing. No wedgies, no riding up, no chafing of my bikini line. I even wore them jogging and didn’t have to pull them out of my crack or adjust them once!

They’re SO comfortable; they fit snugly, but comfortably. Not too tight, not too loose. Period or not, if Goldilocks needed a pair of panties, these are juuuuuuust right.

Are period underwear safe?

Abso-freaking-lutely!

Way safer than disposable tampons and pads that are loaded with toxic chemicals, including carcinogens.

SheThinx products have been tested for harmful chemicals. They are independently certified STANDARD 100 OEKO-TEX using the REACH standards.

For more information about materials, safety, and certifications, click here.

Are period panties for “free bleeders”?

“Free bleeding” is the practice of menstruating without extra products, like tampons, pads, sponges, or cups, to catch, collect, and absorb blood flow. “Free bleeding” is also a movement to support a woman’s right to menstruate publicly, without shame, and without hiding it to make others comfortable.

Women in many countries free bleed because they don’t have access to menstrual products. Other women don’t feel comfortable “shoving something up there”. And others don’t want the waste involved in disposable tampons and pads.

It’s a bit confusing, but period panties are actually considered “allowed” free bleeding wear. Nothing is inserted into the vagina, and period panties are designed to look and feel like regular underwear.

Though technically menstrual products, period underwear allow you to go about your daily life without needing to purchase separate products, change underwear mid-day, or otherwise alter your life. Which leads to the next question…

Are period underwear meant to be worn solo or as a back-up to a tampon/cup/sponge?

SheThinx has designed their period underwear to be worn without any other products. I haven’t tried any other companies’ period underwear, so I can’t weigh in on them.

My daughter and I are both wearing our SheThinx period panties solo — not as a back-up.

My favorite style — the Organic Super Cotton Brief — is for a super heavy flow and holds the equivalent of 4 regular tampons OR 2 regular pads OR 1.25 menstrual cups! I can wear this style for about 10 hours — a whole day — without changing and with no leaks.

I change my regular underwear every morning and every night before bed anyway, so changing period underwear is no different for me.

You totally could wear period underwear as a back-up for your cup/tampon/sponge. If you’re up for it, try wearing only the period underwear for a cycle and see how freeing it is! I never want to use a cup again — and I’ve been a die-hard cup-user for 10 years!

Period undies just feel so much more natural, freeing, and comfortable!

Shop through this link for $10 off your first order!

How many pairs of period underwear is enough?

Well, that depends. Here are some questions to ask when determining how many pairs of period undies you’ll need:

Do I plan to use period underwear as a back-up to my cup/pads/sponge/tampons, or do I plan to wear only period underwear?
If I don’t want to purchase many pairs, what is my commitment level to washing my period underwear frequently enough to have just 2 or 3 pairs? (My advice? 1 pair is NOT enough. You need at least 2 pairs.)
Do I want to use period underwear for my entire cycle or just part of it, such as in the beginning as a back-up to my cup or at the end when my flow is light enough that I feel comfortable wearing period underwear with nothing else?
Do I want to try free bleeding?
How heavy is my cycle?

I started my period underwear trial run with just 1 pair — the Super Organic Cotton Brief. Within the first few hours of wearing them, I knew I wanted to invest in more period panties!

As I said, my daughter and I are free bleeding in our SheThinx period underwear. Because period underwear need to be air dried and that can take as long as 12-14 hours, we need at least 2 pairs. But, we both love our SheThinx period undies so much that we have 4 pairs each!

How often do you have to change them?

So, I started with the Super Organic Cotton Brief. I’m a “hope for the best; prepare for the worst” kind of person. My thinking is it’s better to have the most absorbent period underwear and not need them than to need them and not have them.

The truth about even the most absorbent period underwear is that they still look and feel just like regular panties. There’s no bulk in your crotch!

My first 2 cycle days are heavier, and I wore the Super Organic Cotton Brief for 8 to 10 hours straight — no cup, no tampon, no sponge as a back-up. I free bled straight into the period undies and experienced no leaks!

For my first cycle with period panties, I only had the 1 pair. But, I enjoyed wearing them so much during the first 2 days that I kept washing them to wear for the duration of my cycle, even though my blood flow is significantly less from day 3 to the end of my cycle. (They’re seriously that comfortable!)

SheThinx period underwear are designed to be worn solo. Since the super absorbency undies hold the equivalent of 4 regular tampons or 1.25 cups, how long would it take you to change through 4 tampons or 1.25 cups? That’s how long you can wear 1 pair of super absorbent period underwear.

How do period underwear work at night?

So far, so good!

There’s nothing like the tickling trickle of blood that flows down your butt crack or cheeks at 2 a.m., is there? LMAO

We’ve really enjoyed not waking up to bunched up pads in our crotches or the tell-tale leaks of an over-flowing cup.

We’ve worn our period panties solo, not as a back up to a tampon or cup. If you aren’t sure how period panties will hold up to your overnight flow, I suggest sleeping with a towel underneath you while you test them out.

I have a super clotted flow. Will period panties work for me?

First of all, if your flow is very clotted and those clots are frequently and regularly larger than a quarter, you need to get your hormones checked. A heavily clotted flow is symptomatic of high estrogen and/or low progesterone.

However, until you get your hormone situation figured out, YES, period panties will work for you. You may need a few pairs of super absorbent period panties for those first couple of heavy days, but you’re probably already using a lot of pads or tampons or emptying a cup frequently anyway, right?

Maybe experiment with wearing super absorbent period panties when you can be at home — in case you do have any leaks or monster clots.

If you have to be out and about, wear period panties as a back-up to your tampon, cup, or sponge.

Would I have to change my period underwear at work?

Maybe not. If your workday is 8-10 hours and you wore the most absorbent period undies, it’s likely that 1 pair would last for your entire workday. If you did have to change at work, would that be the worst thing?

Yes, it requires some undressing, but I think rinsing out a menstrual cup in a public bathroom is way harder. You certainly can’t stay in the bathroom stall to rinse it, yet you could change into new period undies in the privacy of your own stall.

Keep a ziploc bag or wet/dry bag in your purse to put your wet undies in, change in your dry pair, and off you go!

Does wearing period underwear feel like sitting in wet undies?

In my opinion, not at all! SheThinx period panties are made with moisture-wicking cotton, so they draw moisture (including sweat!) in and dry really quickly.

I was really shocked at how normal period underwear feel. I could definitely tell when blood flowed out of my vagina, and for a moment — until the blood was absorbed into the undies — it was wet.

It didn’t stay “wet” though. As soon as the blood absorbed into the undies, it felt like wearing underwear with maybe a little discharge. But not “wet”.

What’s the odor situation like?

Surprisingly… pretty odorless. 🙂

Like, WAY less odor than disposable or cloth pads. And way less than a leaky menstrual cup.

Menstrual blood doesn’t smell until it comes into contact with oxygen. While it’s in our bodies, there is no smell.

SheThinx period underwear are designed to neutralize odors. My daughter and I definitely don’t get wafts of menstrual smell when walking around or sitting.

According to the SheThinx website,

The wicking layer of our signature period-absorbing technology has an application of non-migratory silver, commonly used in performance wear and medical devices to control odor and the spread of bacteria. “Non-migratory” means it won’t come off your undies and that it only responds to bacteria *on the fabric*, not on your skin (so your vaginal microbiome stays fresh and balanced!).

My daughter and I feel completely clean and confident at all times when wearing our period panties!

How to wash period underwear?

SheThinx period underwear can be hand-washed or machine-washed. They can be thrown in the washing machine with the rest of your laundry.

JUST MAKE SURE TO HANG THEM TO DRY. DO NOT DRY THEM IN A DRYER!

Tip: to avoid accidentally drying period underwear, add your used undies to a mesh bag and then pull the mesh bag out when the washing cycle is complete.

I personally don’t use any fabric softener or scented detergent.

Do you have to wash period underwear immediately after wearing?

No, though you may want to wash them more frequently if you don’t have many pairs.

It’s probably not a good idea — with any clothing, not just period underwear — to let them sit for many days or weeks without washing them, however.

Other SheThinx users report rinsing their undies out in the shower or in the bathroom sink as a “pre-rinse”, then washing the underwear later. Or, collect your period undies in a mesh bag during your cycle and wash them all together when your cycle is over.

If you think your period undies retain a little bit of stink after washing or if they’ve sat unwashed for a long time, try a vinegar soak. Add 1 cup of white vinegar to 1-2 cups of water and soak your panties for 15 to 20 minutes before washing.

To be clear: we have never had any lingering smell issues because we wash our period underwear within 24 hours of wearing.

Would period panties work for postpartum?

I think so! To be fair… it’s been a minute since I was postpartum (as in 15 years). 😉

From what I remember, that first week is quite bloody. Those long pads and pad ice packs are a god-send, so I’d stick with those. Once your postpartum blood flow becomes more like a heavy period and any tears or stitches are healed, period undies would make a great addition to your postpartum care kit.

Do period underwear work for urinary incontinence?

They totally would… except SheThinx actually has a solution for that — Speax! Speax underwear hold up to 8 teaspoons of urine with the same moisture-wicking, odor-neutralizing technology as Thinx.

Speax are the ideal solution to bladder leaks — a welcome replacement to landfill-clogging disposables — while providing functional, emotional, and cultural benefits

They eliminate the need for sticky pads and disposable incontinence underwear, such as Depends. This is more comfortable for you and more sustainable for the planet — win, win!

Can pre-teens and teens use period underwear?

Yes, they can! SheThinx actually has a line of period undies just for those “in between” menstruators — Thinx BTWN!

You can get a Fresh Start Period Kit with 3 pairs of period underwear for when your daughter starts her period.

Thinx BTWN period panties are made with certified organic cotton to respond to the increasing awareness of toxicity of disposable tampons and pads.

Period underwear seem expensive. Is it really worth the cost? And, why use period underwear at all?

Yup. Even at nearly $40 a pair, I believe period underwear are 100% worth the cost. Here’s why:

The average woman spends over $18,000 in her lifetime on disposable period products. There’s NO way you’re going to shell out nearly that much for a few pairs of period panties — even if you replace them every year for the entire time you menstruate!

I’m protecting my body from the chemicals and toxins in disposable menstrual products while also protecting the planet from the massive amount of trash generated from disposables.

Period underwear are comfortable. Many women find tampons and cups very uncomfortable because of the tilt or length of their cervix, muscle spasm due to pelvic floor dysfunction, uterine, cystocele, or vaginal prolapse, or trauma from sexual abuse. The older I get, the more I’m willing to shell out some cash for personal comfort.

The #1 concern for people on their periods is leaks/leak anxiety. Even with the technology of a menstrual cup, blood still finds its way onto our undies, pants, and sheets. Period underwear significantly reduces (and has eliminated for the menstruators in our home!) leaks and leak anxiety.

What’s the best way to save money on period underwear?

The best way to save money on your investment of SheThinx period underwear is to create a Cycle Set.

buy 3+ pairs = save 10%
buy 5+ pairs = save 15%
buy 7+ pairs = save 20%

You can also save $10 on your first purchase when you shop here!

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Well, is that everything you ever wanted to know about period underwear? If you still have more questions or want to share your own experience, comment below!