But this week, women across the country (including many famous faces!) are smudging their normally perfect pouts in support of the #smearforsmear campaign, an awareness drive for Cervical Cancer Prevention Week and the importance of regular smear tests.
Supermodel and Victoria Secret's angel Cara Delevingne has shared her lipstick selfie with the world and challenged her sister Poppy and best friend Kendall Jenner to do the same.
Reality stars from TOWIE and Made In Chelsea have also got involved, with Lauren Pope and Rosie Fortescue reminding women about cervical cancer and the importance of booking a smear test.
Even soap stars are getting behind this incredibly important cause to help raise awareness. EastEnders' Lacey Turner, who plays new-mum Stacey, and ex-EastEnders actress Kara Tointon have shared their #smearforsmear selfie.
Every single day in the UK nice women are diagnosed with cervical cancer. It's the most common cancer in women under 35, yet one in three young women aged between 25-29 do not attend their screening when invited.
In fact, research from the charity behind the campaign, Jo's Cervical Cancer Trust, shows that a shocking 20% of young women think that cervical screening is an unnecessary health test, rather than a potentially lifesaving process.
No one understands the crucial nature of smear tests more than those who have had cervical cancer. Lucy Wilkins, 32, from Stroud, was diagnosed in December 2010, after a routine smear came back showing some abnormalities.
'First of all, I burst into tears... but after talking to the consultant about what they had found, I was really positive again,' Lucy says.
Lucy Wilkins, 32, was diagnosed with cervical cancer at a routine screening, but was treated quickly and has now been given the all clear
'Luckily they had caught it at a really early stage and I was offered a radical trachelectomy. The cancer had not spread to the lymph nodes and I was all healed. But if I hadn't gone for my routine smear, it might have been a very different story.'
The reasons women give for delaying their smear are often related to embarrassment (26.6%), or concerns that it will be painful (26.2%), but a small amount of discomfort completely outweighs the benefits, which is why #smearforsmear and the awareness it will generate is so important.
These other ladies have already taken part (and a few guys too!):
Here's how you can join them and get involved:
1. Apply your lipstick
2. Smear it and take a selfie<
3. Post on Facebook, Twitter, Instagram or elsewhere online with the hashtag #smearforsmear and nominate a friend to keep the chain of awareness going
4. Text 'CCPW01 £3' to 70070 to give £3 to Jo's Cervical Cancer Trust
And here's our contribution!