Chapped lips? One product you have to use every damn day is probably to blame.

For most of us, chapped lips are similar to kicking a toe, or having something in your eye; it’s comparatively ‘small’ issue but, at the same time, can make the everyday things difficult to enjoy. You find yourself licking your poor lips, which only makes it worse. You can’t eat certain foods without flinching. And it takes days – sometimes weeks – for things to return to normal.

For others – who suffer with ‘chronically chapped lips’ – those poor, cracked, bloody lips hardly ever return to normal.

Luckily, Refinery 29 is on the case having stumbled across a Reddit thread with a possible solution.

“I never in a million years would have guessed my toothpaste was the one to blame. AND my Chapstick wasn’t helping,” Reddit user, dannelinflannel posted to the Skincare Addiction forum.

The writer explained that, after changing to a different toothpaste (one designed for sensitive teeth), and using Vaseline on their lips twice a day, they found an immediate difference.

“Oh my god, the difference it has made in just a week, and it’s the middle of a pretty cold winter here,” the Reddit post reads.

Other users agreed. Some shared their own success in switching toothpastes to treat chapped lips. Others suggested it's an allergic reaction to certain ingredients, for example sodium laureth sulfate.

“Allergic reactions and irritations to toothpaste are unfortunately common,” dermatologist Joshua Zeichner told Refinery 29.

“If you have chronically chapped lips, mouth irritation or burning, or even a rash around the lips that will not go away, you must consider whether it’s your toothpaste that’s having that effect.”

“My morning starts with tongue scraping." Post continues below.

As for the Vaseline compared to the lip balm?

Dermatologist and education manager at Dermalogica Emma Hobson told Mamamia that some lip balms can be temporarily soothing, but actually end up stealing moisture in the long run.

“Avoid lip balms that contain drying ingredients such as menthol or phenol, or possibly unbalanced amount of humectants," she said. "In these cases, where the lip balm doesn't contain sufficient proportions of moisture for the humectant to hold onto, it instead grabs extra moisture from the lips themselves.”

And why are lips so prone to drying out?

“Because the lips don’t contain oil glands which is why lips are prone to drying out especially in cold conditions, a lip balm works by adding moisture, hydration and a surface ‘coating’ to protect the lips from moisture evaporation,” Hobson concludes.

Problem. Solved.