The best and worst underwear for your vagina — and the gross reasons you shouldn’t wear thongs every day

We won’t beat around the bush: When it comes to vaginal health, all underwear is not created equal.

Certain styles and fabrics are better than others at keeping things clean and infection-free down below, according to Winx Health’s medical adviser Dr. Carly Ross.

And while thongs and G-strings are perfectly fine for occasionally avoiding visible panty lines, Dr. Ross told The Post there are some pretty gross reasons you should avoid using them every day.

The best underwear for your vaginal health

Breathe, baby, breathe.

“For everyday wear, sticking to simple, soft, cotton underwear is the healthiest choice,” Ross said.

“Look for underwear that’s free from harsh dyes, synthetic fragrances, or chemical finishes. Underwear made from 100% cotton, especially in the crotch lining, helps keep moisture levels balanced.”

She also recommends moisture-wicking natural fibers, “as long as they’re soft and allow airflow.”

As for which cuts to pick, more coverage is generally going to be better for your bits.

“Styles like briefs, boyshorts or even high-waisted cuts tend to offer the most comfort and coverage without excessive friction,” Ross said.

“The most important factor isn’t just the cut, but the fabric and fit. Underwear shouldn’t be too tight or trap moisture, but it should allow your skin to breathe,” she noted.

And the worst

“The worst style of underwear for vaginal health are tight-fitting thongs or synthetic lace underwear, especially when worn daily,” Ross said.

“Synthetic materials like nylon, polyester, or lace don’t allow the skin to breathe and can trap heat and moisture, creating the perfect breeding ground for yeast and bacteria to grow,” she added.

“Lace and mesh can feel sexy, but they can cause friction and chafing, especially if worn for long periods of time,” Ross said.

Plus, any fabrics treated with fragrances, dyes or chemical finishes can “irritate sensitive vulvar skin and disrupt natural pH balance,” she noted.

But are thongs really that bad?

“Thongs can definitely be a contributing factor to vaginal health issues like UTIs and yeast infections, especially if you live an active lifestyle,” said the doc.

That close fit and friction can be a “breeding ground” for bacteria — including E. coli from back there — which can be carried into the vagina or urethra and lead to urinary tract infections and yeast infections.

That’s especially true if you’re wearing them for a long time or while exercising.

“Wearing them daily might not be the best choice for everyone,” she went on.

“That said, occasional thong use is generally fine if you’re comfortable and not having any issues. But for everyday wear, especially during long or active days, a breathable, cotton-lined, fuller-coverage underwear is usually a healthier option for vulvar and vaginal health,” Ross said.

“Everyone’s body is different, so the key is to pay attention to what feels right for you … Remember — it is fine to wear these styles occasionally but they’re not the healthiest option for everyday use,” she added.

A bonus hygiene tip

“Maintaining good hygiene habits is key to preventing infections,” Ross said.

She recommends a vaginal probiotic like Winx Health’s Vaginal Wellness Kit, which includes both a probiotic and a UTI protection supplement with ingredients like cranberry, D-mannose and vitamin C.