Why Are My Period Undies Leaking? Understanding Causes and How to Prevent It

Period underwear has become a popular, eco-friendly alternative to traditional menstrual products. Designed with special absorbent layers, they promise comfort and protection—but sometimes leaks happen. If you’ve experienced leaking with your period undies, you’re not alone! Let’s explore the common reasons why leaks occur and how you can avoid them.

1. The Absorbency Limit Has Been Reached

Period underwear is designed to hold a certain amount of menstrual flow—usually equivalent to 1-3 regular tampons depending on the brand and style. Once the absorbent core is full, leakage can happen.

Tip: Check the product description for absorbency levels (light, moderate, heavy) and choose accordingly. Change your underwear every 8-12 hours or sooner if you have a heavy flow.

2. Incorrect Fit or Size

If your period underwear doesn’t fit snugly against your body, gaps can form where fluid escapes, causing leaks.

Tip: Make sure you’re wearing the right size. The underwear should fit comfortably but firmly around the waist and legs to create a good seal.

3. Worn Out or Old Underwear

Over time, the absorbent and waterproof layers in period undies can degrade, reducing effectiveness.

Tip: Replace your period underwear after about 1-2 years of regular use, or sooner if you notice reduced absorbency or fabric damage.

4. Heavy Flow Beyond Design Capacity

If your flow is heavier than the underwear’s capacity, leaks are likely, especially on heavy days.

Tip: Use period underwear as backup protection with a tampon or menstrual cup on heavy days, or opt for styles designed for heavy flow.

5. Improper Washing or Care

Washing with bleach, fabric softeners, or at high temperatures can damage the special layers that keep period underwear leak-proof.

Tip: Always follow washing instructions—use cold water, mild detergent, no fabric softener, and air dry to maintain absorbency and waterproofing.

6. Incorrect Positioning or Movement

Period underwear must be positioned correctly to catch flow effectively. Activities like running or bending may cause shifting and leaks if the underwear moves out of place.

Tip: Adjust your underwear to sit securely and consider wearing snug-fitting bottoms or layering for extra security during physical activities.

How to Prevent Leaks: Quick Checklist

  • Choose the right absorbency level for your flow.

  • Get the correct size and ensure a snug fit.

  • Change underwear every 8-12 hours or more frequently if needed.

  • Follow washing and care instructions carefully.

  • Consider using period undies as backup on heavy days.

  • Replace old or worn-out underwear.

Period underwear is a fantastic, sustainable choice, but like any menstrual product, it has limitations. Understanding how they work and how to care for them can help you enjoy leak-free, comfortable protection.

If you’re still experiencing leaks despite these tips, it may be worth trying a different brand or style better suited to your flow and body shape.

Here’s a comprehensive blog post on how to choose the best period underwear and how to care for them properly to maximize comfort, protection, and longevity:

How to Choose the Best Period Underwear and Care for Them Properly

Period underwear has revolutionized menstrual care by offering reusable, comfortable, and eco-friendly protection. But with so many options on the market, how do you pick the best ones for your needs? And once you have them, how do you care for them so they last? This guide will walk you through everything you need to know.

How to Choose the Best Period Underwear

1. Consider Your Flow Level

Period underwear comes in various absorbency levels:

  • Light flow: Suitable for spotting, light days, or as backup.

  • Moderate flow: Ideal for regular days.

  • Heavy flow: Designed for heavy days or overnight use.

Tip: Choose underwear rated for your typical flow, or buy different absorbency levels for different days.

2. Check the Fabric and Comfort

Look for breathable, soft, and stretchy fabrics such as cotton blends or microfiber that feel comfortable against your skin.

  • The underwear should feel like your regular undies — no bulk or stiffness.

  • Avoid itchy or synthetic fabrics that can cause irritation.

3. Look for Reliable Leak Protection Features

Good period underwear typically includes:

  • Multiple absorbent layers that wick moisture away.

  • Waterproof or water-resistant backing to prevent leaks.

  • Snug elastic around legs and waist for a secure fit.

4. Get the Right Size and Fit

Proper fit is crucial to avoid leaks:

  • Measure your waist and hips according to brand size charts.

  • Consider trying a few sizes if you’re unsure, as sizing can vary.

  • The fit should be snug but not too tight or restrictive.

5. Evaluate Brand Reputation and Reviews

  • Check for brands specializing in period underwear with positive customer feedback.

  • Look for transparency about materials, absorbency testing, and return policies.

  • Consider brands that offer guarantees or trials.

6. Price and Sustainability

  • Period underwear is an investment. Higher-quality items may cost more but last longer.

  • Look for eco-friendly production methods and certifications if sustainability is important to you.

How to Care for Period Underwear Properly

Proper care maintains hygiene, odor control, and extends the life of your period underwear.

Step 1: Rinse Immediately After Use

  • Rinse your underwear in cold water to remove blood before washing.

  • Avoid hot water here as it sets stains.

Step 2: Wash Gently

  • Use cold or lukewarm water (max 30°C).

  • Use mild, fragrance-free detergent without bleach or fabric softeners.

  • Hand wash or machine wash on a gentle cycle.

  • Place underwear in a mesh laundry bag if machine washing.

Step 3: Avoid Harmful Products

  • No bleach or fabric softeners—they degrade waterproof and absorbent layers.

  • Avoid harsh stain removers unless they’re safe for delicate fabrics.

Step 4: Air Dry Only

  • Lay flat or hang to dry away from direct sunlight.

  • Do not tumble dry or iron, as heat damages the fabric’s special layers.

Step 5: Store Properly

  • Store period underwear in a clean, dry place.

  • Avoid cramped or humid areas to prevent mildew or odors.

Extra Tips

  • Rotate your period underwear regularly to allow fabrics to fully dry and rest.

  • Replace underwear showing signs of wear, thinning, or leakage.

  • Follow the manufacturer’s specific instructions—they know their products best.

Conclusion

Choosing the best period underwear involves understanding your flow, prioritizing comfort and fit, and selecting trusted brands. Caring for them properly helps keep you fresh, prevents leaks, and ensures your investment lasts.

Period underwear can make your period easier, more comfortable, and more sustainable—when you pick the right pair and care for it well!

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