Thinx vs. Knix vs. ONDRwear: Which Is Right for You?

Looking for a new way to manage your period? Or perhaps you’re one of the many who live with bladder leaks. Now is the best time to get comfortable (and confident!) about it. 

With so many leak-proof underwear brands on the market, how can you be sure to find the best fit for your needs and lifestyle?  

When comparing Thinx vs. Knix vs. ONDR, which is right for you?

We asked around to get you the inside scoop. 

In this guide, we’re comparing the most popular brands so that you can be sure to find the best fit for your needs without compromising comfort and style.

Table of Contents

The Details on Thinx vs. Knix vs. ONDR

Each period-proof underwear brand has its own strengths. 

Depending on your priorities and budget, you can find the perfect pair that makes you feel sexy and confident, and no one will know about your period or incontinence.

Here’s a breakdown on Knix vs. Thinx vs. ONDR to help you decide which brand is best for your needs:





18-36 mL

14 mL

29-44 mL










10 Styles

11 Styles

4 Styles

Odor Protection




Liner Material









Machine Washable




Liner Placement



Forward to Catch

Bladder Leaks






Comparing Thinx vs. Knix vs. ONDR


Designed with “Period Protection” in mind, Thinx states that their underwear can hold the equivalent of 2-4 tampons worth of blood depending on the style you choose — but they aren’t completely liquid proof. 

While Thinx is made from breathable cotton treated with an antimicrobial coating, Thinx is designed to absorb and dry quickly so you can maximize comfort and neutralize odor. 

Every day you wear a pair, throw them in the wash with the rest of your clothes in similar colors. Then hang them out to dry.

But buyer beware: Wearers have claimed that these period panties are not ideal for overnight wear, as the material caused increased sweating and odor.


When it comes to Knix vs. Thinx leak-proof panties, Knix’s has a more extensive line that spans beyond just period panties — they also have sports bras, intimate products, and swimwear.  

The Knix leak-proof line claims they can hold several teaspoons of liquid and can be used for your period and sweating, but unfortunately, cannot hold as much liquid as other brands. 

With triple-layer carbon cotton technology, Knix was designed to be safe. Made 100% free from PFAS and is OEKO-TEX® certified. 

PFAS are chemicals found in many clothing and household products and could potentially cause: 

  • Reproductive
  • Developmental
  • Liver 
  • Kidney, and 
  • Immunological effects 

Although the brand is known for having a wide variety of products, the quality of the underwear is made specifically for period-proofing. If you are experiencing incontinence issues, Knix would not be a good fit for you.



So, where does ONDR fall under the Thinx vs. Knix vs. ONDR review? 

ONDR was designed by a board-certified urologist with extensive experience managing incontinence in her patients. 

ONDR is the most absorbent leak-proof underwear line you can find, so you can live your life freely and without fear.  

When comparing ONDR vs. Knix vs. Thinx, consider the following things about ONDR product quality: 


  • Is made from the sustainable fibers of algae and beechwood fibers
  • Contains an ultra-thin lining that is naturally odor-resistant, antimicrobial, and super soft. 
  • Can hold almost 1/4 a cup of liquid, while still leaving you feeling dry and comfortable all day long. 
  • Is tested regularly by independent laboratories to ensure they are 100% free from PFAS.
  • Can be thrown in the washing machine and worn time and time again.

Sustainability and Saving the Planet With Thinx vs. Knix vs. ONDR: Which Should You Choose?

With single-use leak-proof protection options (panty liners, tampons, pads, diapers, etc), the amount of waste is staggering

Women typically use products like this for more than 40 years, which ends up being a lot of waste. With leak-proof undies, you can wash and reuse them over and over again without losing absorbency, and the planet says thank you! 

All three brands discussed in this article are washable and reusable, so you can feel good about doing your bit to minimize your footprint. 

But ONDR goes one step further to connect with mother earth with revolutionary plant-based liner technology. Move freely and with confidence with the odor-protecting, leak-proof liner that is sourced from algae and other plant materials.

Try ONDR today to experience a new level of freedom from your period and incontinence issues.