They're also ideal for overnight protection (you can pair them with a pad if you have a heavy flow) and for people who are worried about leakage during sports or physical activities. I personally always wear either these period-proof undies or the ones from Thinx when I go on runs on my period, and it has been a MASSIVE godsend. Also, unlike your regular undies, you don't have to scrub the blood out of these. They're designed so it rinses right out in the sink with soap and warm water, and can get tossed in the washer and dryer from there.
Psst — reviewers love these undies, but suggest sizing up!
Promising review: "These are WONDERFUL!! They are super comfortable, soft, have a mild compression to them, breathable, great coverage, not bulky at all, and super absorbent!! You don’t get that metallic blood scent coming through either which I was super skeptical about. So the packaging states that they recommend using these as a backup to another period product like a cup, but I tested the hell out of these babies for my entire period as the only form of protection and left my cup in its drawer. I’m in my thirties. I’m not a super heavy bleeder but I do have fairly heavy days. For the test I used one panty per day (24 hours) and never once had a leak, wetness feel, smell, felt uncomfortable or had bulkiness. When I rinsed them out in the sink after the 24-hour test the amount of blood was astonishing. As you rinse it there’s definitely that old blood kind of metallic smell. Then I just washed them on the gentle cycle and air dried them. Super easy, does take a long time to air dry though. I’ll likely buy more so that I can have daytime and nighttime sets." —Becky
Get it from Amazon for $14.90+ (available in sizes XS-6XL, two colors, and in three-packs).