Why Tattoos Last Forever

That ink isn’t going anywhere. (Photo: Getty Images)

Here’s something you probably haven’t given much thought to: Why do tattoos last forever?

The answer is more interesting than you might think, which is that your body thinks it is under attack when someone draws on it.

It’s actually very difficult for anything to stay on the skin, The Independent reports. We shed about 40,000 skin cells per hour, or around a million per day. Anything drawn onto the skin — by a pen, for example — gradually flakes or gets washed off.

So how do tattoos avoid shedding? The answer is pretty simple — the gun (or other tool used to create the art) pushes the ink through the outer layer of the skin and into the dermis, which is a deeper layer of skin that doesn’t flake off. It’s composed of collagen fibers, nerves, blood glands, and more.

Every time a needle penetrates, it causes a wound. This alerts the body to begin the inflammatory process, which sends immune system cells that try to start repairing the skin — and while this sounds like a bad thing, it’s actually what makes the tattoo last.

The cells try to “eat” the ink and transfer it away from the dermis, but there is more ink than they can break down, so the artwork stays. This is also a window in how laser removal works — the laser breaks down the ink, allowing the cells, called macrophages, to transfer the ink away.

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Want to know more? Check out this video.

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