Why Do Period Undies Smell After Washing? Causes and How to Fix It

Period underwear is a fantastic eco-friendly and comfortable option during your cycle. But sometimes, you might notice an unpleasant smell lingering even after washing. This can be frustrating, especially when you expect your underwear to feel fresh and clean.

Let’s explore the common reasons for this smell and what you can do to keep your period undies smelling great.

Common Causes of Odor in Period Underwear After Washing

1. Residual Blood and Bacteria

Menstrual blood contains proteins and iron that can sometimes bind to fabric fibers. If not washed thoroughly or rinsed properly, some blood residue may remain, allowing bacteria to thrive and cause odors.

2. Improper Washing Techniques

  • Using cold water only without detergent might not fully break down blood and oils.

  • Using fabric softeners or scented detergents can build up on the fabric, trapping odors.

  • Not washing frequently enough or washing multiple pairs together can reduce cleaning efficiency.

3. Poor Drying

  • Insufficient drying, especially in humid conditions, can leave moisture in the fabric, encouraging bacterial growth and mildew smells.

  • Drying indoors without good airflow or sunlight can contribute to lingering odors.

4. Material Build-Up

Period underwear usually contains multiple layers including absorbent and waterproof fabrics (like PUL). Over time, detergents, oils, and sweat can build up in these layers, causing smells.

How to Prevent and Remove Odors from Period Underwear

1. Pre-Rinse Immediately

Rinse your period undies in cold water as soon as possible after use to remove blood before washing.

2. Use the Right Detergent

  • Use mild, fragrance-free detergents designed for sensitive fabrics.

  • Avoid fabric softeners and bleach, which damage waterproof layers and trap odors.

3. Wash Thoroughly

  • Wash in warm water (check care instructions) to help break down oils and residues.

  • Consider adding a small amount of white vinegar or baking soda to the rinse cycle to neutralize odors naturally.

4. Dry Completely

  • Air dry in direct sunlight when possible; UV rays naturally disinfect and deodorize.

  • If using a dryer, use a low heat setting and ensure underwear is fully dry before storing.

5. Occasional Deep Cleaning

  • Soak your undies in a mixture of water and vinegar or baking soda once in a while to remove build-up.

  • Avoid harsh scrubbing that can damage delicate fabrics.

When to Replace Your Period Underwear

Even with good care, period underwear has a lifespan. If odors persist despite cleaning, or if the waterproof layer starts to peel or lose effectiveness, it’s time to replace your underwear.

Final Thoughts

Odors in period underwear after washing are usually caused by residual blood, improper washing, or drying issues. By following proper care routines and choosing the right detergents, you can keep your period undies fresh, clean, and ready for every cycle.

Interested in high-quality period underwear designed for easy care?

Check out NYX Collection Period Underwear.

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