How do they do it?! Celebs who NEVER age!

Getting asked for ID at the off-license used to be the worst thing in the world, but these days it's starting to seem more like a compliment. "You think I look… 17? Oh my god!"

Some celebrities seem to have this aging thing down though. We can only hope to look half as good as them in our thirties and forties!

Here's some of the biggest culprits – the ladies who seem to have totally escaped the perils of growing old…

1. Alicia Silverstone
It's a struggle to tell the fresh-faced Clueless Alicia apart from the 2014 Alicia. At 37 years old, the actress could still pass for a high school teen!

2. Halle Berry
The only reliable way to tell young and "old" Halle Berry apart is the hairstyle. Yes, she's given up that questionable perm these days, but her skin is as flawless as ever. The star says she rubs pure Vitamin C on her face before applying moisturiser. Okay, we're going to need to get some of that, STAT.

3. Jennifer Aniston
If anything, Jenn is actually hotter these days than she was back during Friends' pilot series. The actress, who is now 45 (whaaat?!) has a 30-minute daily beauty routine which involves washing her face with ice water, steaming and cleansing, and putting a dab of Vaseline under each eye.

4. Liv Tyler
These two pictures of Liv might as well have been taken a few days apart. Only the dodgy fringe betrays the fact that the lady on the left is not present-day Liv. The pale beauty is 37 these days and about to give birth to her second child – but she looks as youthful as ever.

5. Reese Witherspoon
Firstly, let's take a moment to giggle at the VERY casual outfit Reese chose for the premiere of True Lies back in 1994. She wouldn't be seen dead on the red carpet in jeans these days! The actress, aged 37, says she uses intensive hydrating moisturiser to keep her looking fresh-faced. Right, off to Boots with us…