Men have become used to growing interesting facial hair during November to raise funds for men's cancers. Now, the organisation behind the moustache-growing challenge is tackling another taboo - mental health.
Justin Coughlan, the Australian co-founder of Movember, which raised more than £20m in the UK last year and £75m worldwide, likens men to cars.
"They need regular servicing, and if you don't look after them they end up broken."
The implication is that men do not look after themselves until it is too late.
The statistic that really shocks him is that 77% of suicides in the UK are male. Every day, an average of 12 men decide to end their lives.
And the problem is not confined to adults. Eleven per cent of boys aged between five and 16 have been diagnosed with a mental health problem.
Zephyr Jussa was one of those. He was 15 when he first realised he was suffering from depression.
His parents divorced when he was six and his mother became increasingly ill, eventually turning to alcohol to deal with her own depression.
Zephyr's relationship with his mother was difficult and strained, and often ended in terrible arguments.
When she died in 2008, he had not spoken to her for several months, and the guilt and anguish overwhelmed him.
"I wasn't really living - I was just functioning. I was spending hours in bed and I felt constantly distraught, trapped, lost at sea," he says.
On top of that, he had no one to confide in. He subsequently failed his GCSEs and didn't have the motivation to go to college.
He struggled on for four years until, at 20, he was "constantly thinking of ways to end it all".
Finally, he sought treatment and spent six months in therapy with other young men with similar problems. It was a revelation.
"I learnt that it's fine to talk about what you feel and what you are going through."
He made close friends and started to turn his life around, to the extent that he is now studying psychology at Coventry University.
He still has to control his depression and look after his mental health - that will never change, he says - but he uses what he has learnt to stop it affecting him too much.
"I want to use my experience to help others. I've told all my university friends and I've even brought up my problems in lectures.
"As a young male, it's OK to have a mental illness and share things. It's not something to be ashamed of."
So what started as a fun movement to save the lives of men affected by prostate cancer, and then testicular cancer, in a Melbourne pub 11 years ago, is now encouraging men to talk about how they really feel, not what they can feel.
"It's the last piece of the puzzle," Justin Coughlan says.
"It's just so big and there's such a need for it."
Movember's aim is to invest in projects in the UK which break down the stigma of mental health issues, which keep people mentally well through talking and sharing their experiences and which offer help and advice when needed.
In Australia, funds have been spent on bringing men together through sport and in men's sheds - where they are most likely to strike up a conversation about their health.
However it is spent, at least £2.5m will go towards supporting men's mental health in the UK from the moustaches grown this month.
Paul Farmer, chief executive of the mental health charity, Mind, says he is delighted.
"There is an urgent need for more services that cater for men in the UK, some of whom are less comfortable discussing emotional issues.
"Our own research showed that almost a third of men would be embarrassed about seeking help for a mental health problem and less than a quarter would visit their GP if they felt down for more than two weeks, in comparison to a third of women.
"As suicide is the biggest killer for men under the age of 35, it's especially important they do not suffer in silence."