The first days of your period are often the hardest. Your belly is bloated, your skin is more sensitive, cramps settle in, and anything that sits too close to your body becomes one more source of discomfort. In that context, the underwear you wear can either make things worse or go completely unnoticed. This guide explains why your period changes what you need from your underwear, and which seamless underwear cut to choose to get through those days as comfortably as possible.
What your period actually does to your body and how clothes feel
Your period is about more than bleeding. It comes with a range of physical symptoms that change the way your body reacts to clothing.
Cramps and uterine contractions
Menstrual cramps, also called dysmenorrhea, are caused by uterine contractions triggered by substances called prostaglandins. According to the NCBI medical library, women with primary dysmenorrhea produce high levels of prostaglandins, leading to stronger contractions and lower abdominal pain that can radiate to the lower back and thighs.
In that context, anything that squeezes your lower belly amplifies the pain you feel. A stiff elastic waistband, a band that's too tight, or a cut that puts pressure on your abdomen adds to the discomfort that's already there. Underwear with no compression in that area is one of the simplest ways to ease the physical strain of those first days.
Bloating and changes in your body shape
During your period, and especially in the days leading up to it, water retention and bloating are common. Your belly and lower abdomen can be a little more swollen than usual, which changes how comfortable a normally well-fitting pair of underwear feels. A cut that was perfect mid-cycle can suddenly feel too tight at the waist or groin for those few days.
A stretchy fabric with a high spandex content, like the 37% in LICA Wear seamless underwear, adapts to these changes without squeezing. Your underwear follows your body as it is that day, without resistance or extra pressure on the most sensitive areas.
Heightened skin sensitivity
The drop in estrogen and progesterone levels at the start of your period can make your skin temporarily more reactive to rubbing and pressure. The side seams of regular underwear, which aren't an issue the rest of the month, can cause irritation or redness during those few days of heightened sensitivity. The laser-cut edges of seamless underwear eliminate those friction points at the source, which is especially helpful during the phases of your cycle when your skin is more reactive.
Higher body heat
The prostaglandins that trigger uterine contractions can also cause a slight rise in body temperature and more sweating during the first days of your period. Fabric that traps moisture in the intimate area makes that heat even more uncomfortable. The nylon-spandex in seamless underwear wicks moisture to the outer surface of the fabric, keeping your skin drier and reducing that feeling of built-up heat.
What to prioritize when choosing underwear for your period
No compression at the belly or groin
This is the most important criterion during the first days. Anything that puts pressure on your lower abdomen or groin adds to cramp pain. A soft high waistband with no stiff elastic is better than any cut whose top edge squeezes your lower belly. High-spandex fabric provides support through natural grip rather than compression, which is exactly what you want at these times.
Soft fabric for more reactive skin
How soft the fabric feels against your skin matters more during your period than mid-cycle. The 63% nylon in LICA Wear seamless underwear offers a smooth, silky surface that doesn't create friction on hypersensitive skin. Unlike untreated cotton fabrics, which can feel slightly rough, nylon-spandex glides over your skin without catching.
The right coverage for comfort and peace of mind
During their period, many women prefer a fuller cut for practical reasons: more fabric offers more security when using period products, and more generous coverage at the back can help you feel more secure on heavy-flow days.
That said, preferences vary from woman to woman and depending on your period protection. What matters most is choosing a cut you feel comfortable and secure in on those days, without sacrificing comfort at the belly and groin.
Which cut to choose based on your symptoms and preferences
The high-waisted thong: the best choice for cramps and bloating
For women dealing with cramps or bloating, the high-waisted thong is often the most comfortable cut during their period. Its nylon-spandex high waistband wraps your lower belly without stiff elastic, creating gentle support rather than compression. Many women describe the feeling as a light, contained warmth over the lower belly, which can make cramps feel less intense.
Its minimal back keeps heat from building up around your buttocks, which is a welcome relief on days when your body temperature runs slightly higher. The seamless high-waisted thong collection offers this style in dark colors that are especially well suited to period days.
The seamless bikini brief: coverage and stability for heavy flow
For women who value coverage and stability during their period, especially on heavy-flow days or when using certain period products, the seamless bikini brief is a solid option. Its fuller cut at the front and back offers more fabric, which can be reassuring on the heaviest days.
Its nylon-spandex fabric stays light and friction-free despite the more generous coverage, and its laser-cut edges eliminate pressure points on the hips and thighs. The seamless bikini brief collection is available in dark shades that are especially well suited to period days.
The seamless Brazilian brief: the versatile in-between
For women with moderate symptoms, the Brazilian brief offers a good balance between coverage and lightness. It covers more of your buttocks than a thong while staying lighter than a bikini brief, and its high-cut leg avoids pressure on the hips, an area that's often sensitive during your period. It's often the pick for women who want extra comfort without drastically changing their habits. The seamless Brazilian brief collection also comes in dark colors for period days.
What about color during your period?
Dark shades, like Noir Noble from the LICA Wear collection, are the most practical during your period for obvious reasons: they hide any stains and let you feel more at ease without constantly checking your underwear. Setting aside a few pairs specifically for period days is a simple habit that removes a source of anxiety during those few days of the month.
You don't need a separate period wardrobe, but designating two or three dark pairs for those days lets you wear them without a second thought and save your light and nude shades for the rest of your cycle.
Other habits that help during your period
Underwear is one piece of the puzzle when it comes to period comfort. A few simple habits make a real difference.
Changing your underwear more often than usual, especially on heavy-flow days, keeps your intimate area fresh and comfortable. The 100% pre-shrunk cotton gusset in all LICA Wear seamless underwear provides the breathability that area needs, which is especially important during your period, when there's more moisture and heat.
Keeping a clean spare pair handy at work or in your bag is a simple precaution that saves you from the discomfort of a long day with no chance to change.
If your period falls on long workdays, the article on which seamless underwear to choose for long workdays offers more pointers on staying comfortable through long hours of sitting.
And to learn how to adapt your underwear to your whole menstrual cycle, not just your period, LICA Wear's article on underwear and the menstrual cycle covers each of the four phases in detail.
FAQ: seamless underwear during your period
Which seamless underwear cut is most comfortable during menstrual cramps?
The high-waisted thong is generally the most comfortable cut during cramps, because its nylon-spandex high waistband gently wraps your lower belly without squeezing. That light, contained warmth can help make cramps feel less intense, a bit like a gentle hot water bottle. On the other hand, cuts with stiff elastic waistbands or that squeeze your lower abdomen amplify the pain by adding outside pressure to the uterine contractions already happening. If the high-waisted thong isn't for you, the seamless bikini brief is a good alternative: its fuller cut stays soft on your belly because there's no sewn-on elastic.
Does seamless underwear work with all period products?
Yes, nylon-spandex seamless underwear works with pads, tampons, menstrual cups, and discs. It isn't period underwear in the strict sense, meaning it doesn't have a built-in absorbent layer. You wear it like regular underwear with the period product of your choice. On heavy-flow days, the seamless bikini brief or Brazilian brief offers more fabric, which can help keep certain products more stable, especially adhesive pads.
Why does my usual underwear feel tighter during my period?
That's completely normal. The bloating and water retention that often come with your period, and especially the premenstrual phase, make your belly and lower abdomen swell slightly. Underwear that fits perfectly mid-cycle can feel tighter at the waist or groin for those few days, even without any change in weight. That's one of the reasons high-spandex fabric is especially well suited to your period: it adapts to these temporary changes without creating pressure points. If the tight feeling is very noticeable even in seamless underwear, it may be a sign that a slightly larger size would be more comfortable for those specific days.
Your period puts your body through a lot for a few days every month, and the underwear you wear during that time deserves some thought. Seamless underwear in the right cut, with no stiff elastic, in a soft, stretchy fabric that manages moisture, genuinely reduces outside sources of discomfort on days that are already demanding. The high-waisted thong for cramps and bloating, the bikini brief for heavy flow, the Brazilian brief for moderate symptoms: there's a cut for every need, and a few pairs set aside for period days are all it takes to get through them with far less discomfort than you might think.
