A green lipstick that appears clear when applied changes “magically” into different shades of pink, according to the wearer’s body chemistry.

The green lipstick – variations of which are sold by Dior, Smashbox and Mood Magic – reportedly contains a dye called Red 27, which reacts to the pH balance and temperature of the wearer’s lips, causing the color change.

Be warned that a mirror is necessary when applying it; unlike typical lipsticks, this one temporarily stains and can remain on the lips for hours.

Many of today’s variations on the lipstick, which has apparently been available in Morocco and countries in Asia for decades, are advertised as “mood” lipsticks that change according to your emotions.

While the shade of pink produced by the lipstick actually has nothing to do with mood, it can be affected by someone’s diet and stress level, both of which have an impact on pH levels in the skin.

Some wearers have lauded the product, which ranges in price from $3.19 to $30, as “magical” for customizing the perfect hue for their skin tone.

Green lipstick contains a dye called Red 27, which reacts to the pH balance and temperature of the wearer’s lips, causing the color change

ManRepeller blogger Leandra Medine got her hands on a Magic Moroccan Hare Color-Changing Lipstick and decided to give it a try, documenting the results in a series of before-and-after photos.

She said when she looked into the mirror after applying the product, “the color had grown deeper, darker and far more suitable to augment but simultaneously endorse the state of my lips’ innate color”.

Indeed, the photos show her lips transforming from their natural, paler color, to a darker rosy hue.

“I’m still not quite sure how the glorified, semi-permanent lip tattoo knows how to ink me in a way that seems so precisely aware of that which <<works>> on me,” wrote Leandra Medine.

There is, however, no science to back up the claims that these products magically transform into the hue that best suits the wearer.

In fact, when Examiner writer Lindsay Carbone tried on $30 Dior Addict Lip Glow, a similar lipstick, “a toxic hot pink color set in and was quite bright and unsuitable to my skin stone”, she wrote.

“In other words, it wasn’t flattering at all.”

And wearers should be warned that the lipstick’s dying properties mean that it can be particularly difficult to remove.

“We used to get these in Mexico as kids to play make-up,” wrote one ManRepeller commenter.

“They really are a pain to take [off] later on.”

Other similar products include Smashbox O-Gloss, which costs $23 on Sephora.com, and Mood Magic Perfect Pink, which can be purchased for $3.19 at K-Mart or on the Mood Magic website.