Why your period undies smell and top tips for stopping and preventing odors

Cleaning and Caring for Period Undies

Menstruation is a natural and significant aspect of life, and finding reliable and comfortable period products are crucial for peace of body and mind. Enter period underwear – an innovative product designed to offer convenience, sustainability, and practicality. In this post, we delve deeper into the science behind period fluids, the role of bacteria in causing odors, the unique challenges posed by synthetic fibers, and provide you with effective methods to clean and maintain your period undies.

Understanding Period Fluids and Bacteria:

Menstrual fluids, often comprised of blood and uterine lining, are essential components of the menstrual cycle. These fluids contain essential nutrients and components that normally nourish the body and facilitate the shedding of the uterine lining. However, once passed put of the body, these fluids are also nourishing to bacteria and fungi. This is where bacteria and other microbes come into play. Bacteria, which naturally live in and on our bodies, can break down these fluids and thrive in the warm and moist environment of period undies. As these bacteria multiply, they release byproducts that contribute to the less-than-pleasant odor associated with period undies.

The Role of Bacteria:

Bacteria are living organisms that feed on organic matter, like body fluids. In the context of period fluids, they play a crucial role in breaking down blood components. However, this breakdown process can lead to the release of volatile compounds responsible for the recognizable odor. The warm and humid environment created by menstrual fluids offers the perfect breeding ground for these bacteria to flourish. Hence, managing bacterial growth is not only essential for maintaining personal comfort but also for ensuring optimal hygiene during menstruation.

Synthetic Fibers and Bacterial Growth:

Period underwear often features synthetic fibers like nylon, polyester, and elastane, chosen for their moisture-wicking properties and comfort. However, these materials can inadvertently contribute to bacterial growth due to their structure. The smooth and moisture-trapping nature of synthetic fibers provides an ideal surface for bacteria to cling onto and multiply. Unlike natural fibers that allow air circulation, synthetic fibers can trap heat and moisture, creating conditions conducive to bacterial colonization. Moreover, synthetic fibers don't wash well due to their water-repellent nature. So even machine washing with heavy duty detergent doesn't kill all the bacteria.

Effective Cleaning and Washing Methods:

To ensure that your period undies remain fresh, comfortable, and free from bacterial growth, consider adopting the following cleaning practices:

  1. Immediate Rinsing: After use, promptly rinse your period undies in cold water. This step helps remove excess fluids, preventing stains from setting in and helping to remove some of what the bacteria are living on.
  2. Detergent Selection: Choose fragrance-free detergents when washing your period undies. Harsh chemicals and fragrances can irritate the sensitive skin in the genital area and often don't kill the odor causing bacteria.
  3. Cold Water Wash: Washing in cold water is essential as hot water can coagulate blood proteins, making them harder to remove. Cold water ensures proper cleaning, but unfortunately doesn't help to sterilize the undies.
  4. Avoid Fabric Softeners: Fabric softeners can leave a residue on synthetic fibers, compromising their absorbency and promoting bacterial growth. Skip fabric softeners to maintain the integrity of your period undies.
  5. Gentle Air Drying: After washing, allow your period undies to air dry, preferably in the sun. The UV from the sun can help kill the bacteria, but might not penetrate deep enough to kill all the bacteria.
  6. Use odor protection products: Newly invented odor-protection products,  like SWIFF spray that kill the cause of odors and prevent them from returning are a game-changer for period undies. These products use the power of silver ions and natural polyphenols to kill odor-causing microbes and create a protective barrier that prevents future bacteria from growing on your undies.


Overall, period undies are a transformative solution that revolutionizes the menstrual experience, offering unparalleled comfort and environmental benefits. By delving into the intricate details of period fluids, bacterial growth, and synthetic fibers, we've unlocked the key to maintaining optimal hygiene and reducing odors. Implementing the prescribed cleaning methods ensures that your period undies remain an effective, comfortable, and reliable choice, fostering a sense of confidence and well-being throughout your menstrual cycle.