Global beauty brand MAC Cosmetics has announced its collaboration with world-renowned singer Sia in honour of World AIDS Day. Sia will launch her very own red lipstick as part of the brand's Viva Glam range which will be available instore and from maccosmetics.co.uk from February 2018. All money raised from the sales of the lipstick will go towards the M·A·C AIDS Fund which goes directly to people affected by HIV/AIDS.