The best pad is the one that matches your flow, fits your body, and doesn’t irritate your skin. That sounds simple, but the range of options (menstrual, postpartum, incontinence) and the differences in absorbency, materials, and design are bigger than most people realize. A heavy-day menstrual pad can hold anywhere from 31 to 52 mL of blood depending on the brand, while a light-day pad holds only about 4 mL. Choosing well starts with understanding what actually separates one pad from another.
How Pad Absorbency Actually Works
Most disposable pads use superabsorbent polymer in the core, a material that locks fluid into a gel so it doesn’t feel wet against your skin. In lab testing, a commercial pad with this polymer had an absorption index of about 4.4, meaning it absorbed over four times its own dry weight. Cotton terry cloth, by comparison, absorbed less than its own weight (index of 0.84). Hemp and linen performed slightly better but still fell well short of synthetic cores.
Bamboo wadding was a standout in the same study, absorbing nearly eight times its dry weight (index of 7.86), which is why some reusable pad brands have shifted toward bamboo-based cores. If you’re considering reusable pads, the core material matters more than the outer fabric. Look for bamboo or multilayer designs rather than single-layer cotton.
One important caveat: no industry standard exists for testing pad capacity the way there is for tampons. The milliliter numbers on packaging aren’t measured the same way across brands, so comparing two products by their advertised absorbency isn’t always reliable.
Menstrual Pads: Choosing by Flow
Menstrual pads are designed around the fact that blood flows gradually over hours, not all at once. They tend to be thinner (averaging about 1.9 mm) and narrower (about 7.5 cm wide) than pads built for other purposes. Wings are common because they anchor the pad to underwear and create a barrier against side staining.
For light days or spotting, a thin liner or light pad (around 4 mL capacity) keeps things comfortable without bulk. For heavy days, lab-tested pads ranged from 31 to 52 mL of actual blood capacity. That’s a significant gap between brands at the same “heavy” label, so if you’re leaking through one brand’s heavy pad, try another before jumping to a bigger size. Overnight pads are typically longer in the back to prevent leaks while lying down, and many people find that a heavy-day pad with an extended back panel works better at night than a standard overnight pad that’s bulky but poorly shaped.
Postpartum Pads Are a Different Category
After childbirth, bleeding (called lochia) is heavier than a typical period and can last several weeks. Standard menstrual pads often aren’t enough. Postpartum pads are thicker, wider, and longer in the back to handle heavier flow in multiple positions, whether you’re standing, sitting, or lying down. In testing, a postpartum pad held about 40 mL of blood, which falls in the mid-range of heavy menstrual pads but with a much larger surface area.
Material matters here more than with everyday pads. Postpartum tissue is often swollen or healing from tears or stitches, so soft, breathable materials reduce friction and allow airflow. Avoid anything with a plastic-feeling top sheet. If a pad feels stiff or crinkly out of the package, it’s likely to be uncomfortable against sensitive skin. Many people layer a postpartum pad with a peri-bottle rinse rather than wiping, which also reduces irritation.
Incontinence Pads vs. Menstrual Pads
If you’re managing bladder leaks, a menstrual pad is the wrong tool. Urine comes in fast bursts, reaching flow rates of 20 to 30 mL per second, while menstrual blood seeps out slowly. Incontinence pads are engineered for rapid absorption to prevent runoff before the fluid soaks in.
The structural differences are significant. Incontinence pads average 7.1 mm thick compared to 1.9 mm for menstrual products, and they’re wider (9.6 cm vs. 7.5 cm). Most use fluff pulp in the core, which helps the pad conform to your body and channels fluid toward the center. Many also have lateral elastic in the cover that curves the pad into a gutter shape, directing liquid inward instead of letting it spill sideways. Wings are actually rare on incontinence pads because they can pull the pad downward and increase leakage risk.
If you’re using menstrual pads for light bladder leaks and finding them inadequate, switching to a product specifically designed for incontinence will likely solve the problem. Even a thin incontinence liner absorbs faster than a thick menstrual pad.
Skin Irritation and What Causes It
Vulvar dermatitis from pads is common and often misidentified as a yeast infection. The usual culprits are fragrances, adhesive chemicals, and synthetic top sheets that trap moisture. Scented pads are one of the most frequent triggers. If you’re experiencing itching, redness, or a burning sensation that lines up with where your pad sits, try switching to an unscented pad with a cotton or bamboo top sheet before assuming you have an infection.
Breathability also plays a role. Pads with a waterproof plastic backing prevent leaks effectively but can create a warm, moist environment that encourages irritation. Some brands now use microporous backings that resist liquid but allow some air exchange. If you’re prone to irritation, these are worth seeking out.
Chemical Safety in Reusable Products
Reusable pads and period underwear have grown popular for environmental and comfort reasons, but they’re not automatically free of concerning chemicals. Researchers at the University of Notre Dame tested over 70 reusable products across multiple continents and found that 25 percent of reusable pads and 33 percent of period underwear showed signs of intentional PFAS treatment, the “forever chemicals” used to make fabrics water-resistant. The majority of products tested (about 71 percent) had only trace levels consistent with background contamination, not deliberate addition.
The takeaway: PFAS aren’t necessary to make these products work, since most brands don’t use them. But there’s no easy way to tell from the label. Certifications like GOTS (Global Organic Textile Standard) prohibit toxic chemicals including heavy metals and known environmental hazards, and require organic fibers grown without synthetic pesticides or GMOs. If chemical exposure concerns you, GOTS-certified products are among the most rigorously vetted options available.
How to Pick the Right Pad for You
Start with your primary need. For everyday menstrual use, match pad size to your flow and upgrade the brand before upgrading the size if you’re experiencing leaks. For overnight protection, prioritize length over thickness. For postpartum recovery, choose the softest, most breathable option you can find in a large size, and plan to use them for at least two to three weeks.
For bladder leaks of any severity, use a product labeled for incontinence rather than repurposing menstrual pads. The absorption speed difference is real and matters more than total capacity.
If skin sensitivity is an issue, eliminate fragrance first, then try switching to a cotton or bamboo top sheet. For reusable products, look for GOTS certification or brands that explicitly disclose their chemical testing. And if you’re comparing absorbency claims across brands, remember that there’s no standardized testing method for pads, so treat those numbers as rough guides rather than precise measurements.