Myth-Busting 5 Common Underwear Rules - As Heard on the Style-ish Podcast

When it comes to underwear, we all have our preferred styles, comfortable favourites, and a few “rules” we’ve picked up along the way. But how many of these rules are actually true?

Recently, Style-ish hosts Maddison Sullivan-Thorpe, Joanna Fleming, and Annika Joshi-Smith spoke with experts from Women's Health Melbourne and Intimate Ecology to explore five of the most common underwear myths, with a warm mention of Primary along the way.

Myth 1: Not Wearing a Bra Causes Breasts to Sag Prematurely
Mostly fiction. There is no solid scientific evidence linking going bra-free to sagging. The most significant factors are breast weight, skin quality, genetics, and life stages such as pregnancy or breastfeeding. Choosing to wear a bra regularly is more about comfort than prevention. However, Cooper’s ligaments — the connective tissue that helps maintain breast shape — can stretch over time, and a well-fitted bra may help reduce this.

Myth 2: You’re Probably Wearing the Wrong Bra Size
True for many. Our bodies change over time, brand sizing varies, and it’s common to rely on guesswork. Around 80% of people are in the wrong size. Being professionally fitted, and re-fitted regularly, can transform both comfort and appearance. Joanna favours soft, wireless styles at home, while Maddison prefers structured underwire for daily wear. For occasions when style is as important as fit, Maddison recommends Primary’s curated range, perfect for sheer tops and special outfits.

Myth 3: Sleeping Commando is the Healthiest Option
Not always. While going without underwear at night can allow skin to breathe, the healthiest option depends on climate, comfort, and hygiene. If you prefer wearing underwear to bed, choose natural fibres and looser fits.

Myth 4: Cotton is Always the Best Fabric for Underwear
Partially true. Cotton is breathable and gentle, but other natural fibres such as bamboo and hemp can be just as effective, particularly in warmer climates. The most important feature is a breathable gusset to help avoid trapping moisture.

Myth 5: Underwire Bras Can Cause Breast Cancer
Firmly debunked. Despite persistent rumours, there is no scientific evidence connecting underwire bras to breast cancer. Experts confirm they are safe.

Listen to the full episode of Style-ish, “Myth-Busting 5 Underwear Rules,” to hear every insight and story. When you’re ready to refresh your lingerie drawer, discover the latest Primary collection.