Revealed... why your penis and nipples are darker than the rest of your skin: Sex hormones cause pigmentation in puberty - but 'darkening can be a sign of diabetes'
- A person's genitals are usually darker than the rest of their body
- Experts reveal the darkening occurs because of hormones in puberty
- Extra testosterone can cause a man's penis and nipples to darken
- Similarly estrogen can cause a woman's labia and aerola to darken
- But, darkening can also occur because of health problems, doctors warn
Have you ever wondered why your genitals are darker than the rest of your body?
Regardless of race, a person's penis and nipples, areolas and labia are naturally a shade or two deeper in color than their skin.
And the reason? Darkening occurs during puberty, experts told Daily Mail Online.
As sex hormones surge through the body they stimulate the production of melanin - the amino acid responsible for hair and skin color.
The result is for the skin on a man's penis and nipples and a woman's areolas and labia, to darken.
While the process is a natural one, experts warn, any further darkening in adulthood could be a sign of the chronic illness, diabetes.
Dr Lindsey Bordone, a dermatologist at Columbia University Medical Center in New York, told Daily Mail Online: ‘Your skin can darken in certain areas when your sugars are very high – and you’re developing diabetes.’
It's common for men and women to have genitals and nipples that are darker than the rest of their skin, experts reveal. The change in pigmentation largely occur because sex hormones stimulate production of melanin during puberty
For instance, some people are born with blonde hair that later turns brown.
Dr Bordone said: ‘When girls are young, their nipples are light. And as they get older, hormones have an effect and the nipples darken. ‘It’s very similar for boys.’
But, when puberty kicks in, women experience an increase in estrogen, while men experience an influx of testosterone. Those hormones regulate melanocytes – which are skin cells that produce melanin, said Dr Cameron Rokhsar, an associate clinical professor of dermatology at Mt. Sinai Medical Center in New York.
Your skin can darken in certain areas when your sugars are very high – and you’re developing diabetes
Dr Lindsey Bordone, a dermatologist at Columbia University Medical Center
Dr Rokhsar told Daily Mail Online: ‘Hormones regulate the way melanocytes produce their pigment.
‘Those can have an effect on the way the skin in that area pigments, so generally that area is darker.’
Hormones can also affect pigmentation in adulthood, especially in women.
When a woman is pregnant – or goes on birth control pills – she can experience heightened levels of estrogen.
That increase in hormones can cause pigmentation in a woman's face.
Dr Rokhsar added: ‘In pregnancy, women can also develop a dark line on their abdomen.’
Furthermore, external factors – especially friction – can affect pigmentation after puberty.
When the skin experiences friction, it naturally thickens to protect itself, she explained.
