NIXI Body Polly Leakproof Knicker — Heavy Absorbency

Meet the heavy period knickers that prove protection and prettiness aren't mutually exclusive. The NIXI Body Polly combines super-absorbent leakproof technology with delicate lace detailing and a high-waisted silhouette — holding up to 25ml (4–5 tampons) for total confidence on your heaviest days and through the night. Available in sizes 8–24, the Polly is the most inclusive style in the NIXI Body range.

Why You'll Feel Confident in the NIXI Body Polly Knicker

How to Wear the Polly Knicker with Confidence

The Polly is your go-to for the days — and nights — when you need to know you're completely covered. Wear it alone on heavy flow days and let the four-layer, wide-gusset design do the work, or pair with a menstrual cup on your very heaviest days for an extra layer of reassurance. The high waist sits comfortably and securely, making it particularly brilliant for overnight protection.

Unlike purely functional period underwear, the Polly's lace detailing means it genuinely feels like a nice pair of knickers — not a medical necessity. Wear it under pyjamas, a nightdress or loungewear and wake up feeling comfortable and protected, every single morning of your cycle.

Build your complete period wardrobe by pairing the Polly with the Gracie Thong for lighter days and the Carla Heavy Knicker for daytime heavy flow. Browse our full period pants & period underwear collection, or explore our wider lingerie & underwear edit for everyday essentials.

Sizing, Fit & Care Tips

Frequently Asked Questions

How much do the Polly heavy period knickers hold?

The Polly holds up to 25ml — the equivalent of 4–5 tampons, making it the highest-absorbency style in the NIXI Body range. It's designed for heavy periods, overnight wear, postpartum flow and anyone who needs maximum protection without compromise.

Are the Polly knickers good for overnight use?

Yes — the Polly is specifically designed with overnight wear in mind. The high waist and wider gusset provide broader coverage and a more secure fit when lying down, so you can sleep through your heaviest nights with complete confidence.

What size should I order?

The Polly runs true to size — simply select your usual UK size. Available in sizes 8–24, making it one of the most size-inclusive period knickers available. If you're unsure, our UK customer service team is always happy to help — just drop us a message and expect a warm, honest response.

How is the Polly different from the Carla?

Both are heavy absorbency period knickers, but the Polly holds slightly more (25ml vs 20ml), has a wider gusset for broader coverage, a high-waisted cut for added comfort, and pretty lace detailing. The Polly is particularly suited to overnight wear and those who want a more elevated look. The Carla is a lower-rise, VPL-free style better suited to daytime wear under fitted clothing.

Ready to Sleep Through Your Heaviest Nights?

The NIXI Body Polly Leakproof Knicker is the period underwear for women who refuse to let their cycle disrupt their sleep, their comfort or their confidence. Maximum absorbency, beautiful lace detailing and a fit that works for every body — from size 8 to 24. Add your size to your basket today. Shop the full period pants collection →

You May Also Like

• Period Pants & Period Underwear
• Luxury Lingerie & Underwear
• Gifts for Women
• Bath, Beauty & Wellness