In this article
As a longtime menstrual cup devotee, I’ve always been curious about period underwear. In the long run, they’re cost-effective and a reusable alternative to tampons and pads. Finding the right pair takes a lot of trial and error, however. Periods fluctuate, not only person-to-person but day-to-day. After testing out 14 pairs, I found I prefer different styles for overnight and daytime, and I even found some that I’d wear in addition to my menstrual cup for backup protection. It’s all based on personal preference, though, so I’ve included a range of options below. For the most part, it’s all sorted from heaviest to lightest absorbency.
Before I get into the best period underwear picks, though, a note on forever chemicals: When I spoke to gynecologist Dr. Jen Gunter on the subject, she said, “There’s no association of any of these products with any health concerns, and the majority of experts agree.” She explains, however, that the risk lies in environmental contamination: “For people who want to be mindful of that, just like with any other product, you might want to choose a product that is free of those chemicals because you care about the environment. It’s less about worrying about something that’s going to jump up into your reproductive tract and cause you harm. We don’t have any data to suggest that’s a concern, but the global manufacturing of forever chemicals is a problem for our environment.” Now, onto the underwear: from ultra-absorbent flattering pairs to comfortable thongs.
What we’re looking for
Absorbency
Period underwear is made with gussets that have different levels of absorbency. The lightest ones are best for backup in addition to other period products; medium ones give you protection without bulky material; and heavy and super are best for days when your flow is the heaviest or at night. I like having a range of options throughout my own period.
Material
Here, I’ve listed all of the materials provided on the brand’s website, including what the outer, gusset, and liner parts of the underwear are made of.
Sizing
In line with the rest of our fashion coverage, we aim to include the most size-inclusive options. To make shopping easier, you’ll find the range of sizes available here.
Best period underwear overall
Absorbency: Super | Material: Organic cotton with spandex jersey (outer); polyester (absorbent); polyester PUL (leakproof) | Sizing: XS to 6XL
Period Company, started by celebrity stylist Karla Welch, was top of my list after reading Strategist contributor Liz Carey’s review of the brand’s high-waisted pair. Out of all the brands I tested, these were my favorite. The material is substantial without feeling too bulky, and the gusset is made with four layers of leak-resistant fabric. It’s also flattering without cutting into my skin around the waistband or leg openings. I’ve reached for the high-waisted pair for heavy flow days and haven’t had any issues with leaking. At just $12 a pair for the heaviest absorbency, I think it’s also pretty affordable. (The brand has a number of styles for just $9.) The one potential drawback is the lack of colors and patterns; they only come in solid black, tan, and brown. But they make up for it by being available in a wide range of sizes and styles including bikini, thong, boxer, and even an adaptive option.
Best overnight period underwear
Absorbency: Heavy | Material: Bamboo viscose spandex (outer); cotton, spandex (inner); polyester, nylon (absorbent); polyester TPU (leakproof) | Sizing: XXS to 6XL
For nights I’m on my period, I want maximum protection to ensure my sheets aren’t stained while I’m sleeping. Like the other heavy-absorbency pairs featured, the absorbent layer is able to hold up to four tampons, but it covers a wider area. It extends further up the back and wider, as does the leakproof layer for extra protection. Because of this, I felt most comfortable sleeping in these, even on my heaviest days. They are thicker and less stretchy than the Period Company underwear, but that’s to be expected from a product that’s branded as shorts instead of underwear. With that said, I could see myself wearing these on their own as boy shorts for lounging at home or even under flowy dresses instead of my usual bike shorts, but they are a bit bulky for wearing under tighter-fitting bottoms.
Best lightweight overnight period underwear
Absorbency: Heavy | Material: 92% Tencel modal, 8% elastane | Sizing: 3XS to 6XL
Awwa’s period boxer briefs are made mostly out of tencel modal, which our deals editor Sam Daly says are “incredibly sleek and smooth.” They’re more lightweight than the above pair, but still absorbent enough to work for heavier-flow days and overnight. She prefers wearing them as sleep shorts, but she’s worn them underneath shorts and pants, too. The legs do tend to roll up underneath tighter-fitting jeans, but it’s an easy adjustment, she says. Daly especially likes that these aren’t constrictive like other period underwear she’s tried. Instead, these are comfortably snug and don’t pinch around the leg openings.
Best period underwear with reusable pads
Absorbency: Super | Material: Tencel Lyocell, organic cotton, spandex (body); recycled polyester, organic cotton, TPU (gusset); recycled polyester, organic cotton (lining); recycled polyester, polyester, hemp (booster) | Sizing: XXS to 5XL
Instead of relying solely on a built-in absorbent layer, Aisle’s underwear is made with an absorbent layer and removable insert. With the booster, it’s said to absorb up to eight tampons, which is more than any of the other pairs on this list. I chose to try out the hipster underwear to see if they could hold up on heavy days. I think that they do, with the one downside that these are a little thick and the silhouette may show underneath some clothes (like leggings or tight jeans). But, if you are wanting extra protection and aren’t worried about that, these are an excellent option.
Best bikini-cut period underwear
Absorbency: Heavy | Material: Bamboo viscose, elastane (outer); merino wool, polyester (gusset) | Sizing: 0 to 14
ModiBodi was a brand that I found while searching our archives on the Strategist UK. Two experts were fans of this bikini-style underwear, which is said to absorb three to four tampons. Anna Hamill, an illustrator, hand-letterer, and designer, said that this particular pair was able to last longer than other period underwear she has tried. I’ve yet to try them for myself, but I like that they come in a wide variety of sizes, silhouettes, and colors.
Best boy-brief period underwear
Absorbency: Light to medium | Material: Cotton, elastane | Sizing: XXS to XXL
Aerie was another brand I looked into, because I’ve always liked the fit and feel of its regular underwear. The period underwear was no different: It’s extremely comfortable, soft, and not too bulky. I wore these on lighter days since they’re only said to hold up to two tampons, and it felt like I was wearing my normal cotton underwear. The drawback with these is their lack of sizing and silhouette options, but the company has recently expanded the line to include high-rise boy briefs, boy shorts, and running shorts with absorbent gussets.
Best seamless period underwear
Absorbency: Medium | Material: Nylon, LYCRA spandex (body); cotton, spandex, carbon (gusset 1); polyester, spandex (gusset 2); polyester, spandex, polyurethane (gusset 3) | Sizing: XS to 4XL
What stood out to me about Knix’s offerings was its UltraThin line of period underwear, especially because most of the other brands opted for thicker materials. I was shocked that I could wear the French-cut underwear underneath bike shorts and leggings without the seams showing. The medium absorbency (three to four tampons’ worth) was enough to get me through days when my flow was lighter. I could also see myself wearing these as backup when I’m wearing a menstrual cup. They also come in heavy absorbency, which is said to absorb three regular pads or six super-tampons, but I haven’t tried those out yet.
Best thong period underwear
Absorbency: Light | Material: Nylon, LYCRA spandex (body); cotton, spandex, carbon (gusset 1); polyester, spandex (gusset 2); polyester, spandex, polyurethane (gusset 3) | Sizing: XS to 4XL
It shouldn’t come as a surprise that Knix also won in this category, since its UltraThin line is virtually seamless. I would use these only as a backup while wearing a menstrual cup or on the last day of my period when I knew I would only be spotting, because the coverage is really minimal. Like the French-cut pair above, these come in a wide range of sizes and a decent amount of colors.
Our experts
• Liz Carey, Strategist contributor
• Anna Hamill, illustrator, hand-letterer, and designer
• Dr. Jen Gunter, gynecologist
The Strategist is designed to surface the most useful, expert recommendations for things to buy across the vast e-commerce landscape. Some of our latest conquests include the best acne treatments, rolling luggage, pillows for side sleepers, natural anxiety remedies, and bath towels. We update links when possible, but note that deals can expire and all prices are subject to change.
