Welcome to November, the month where all your male friends and co-workers show up clean-shaven and baby-faced on Nov. 1 and look like western-movie villains or grizzly bears by Thanksgiving.
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Growing out one's facial hair for 30 days is called "Movember" or "No-Shave November," and it's meant to raise awareness for cancer. It's also a chance for dudes to show off their 'staches, goatees, Fu Manchus, mutton chops and other furry face-warmers.
Here's your guide to the mustachioed month-long event:
What is Movember?
Movember began in Australia in 2003 to raise awareness for prostate and testicular cancers, according to the Movember Foundation, a nonprofit that raised nearly $21 million in 2013.
"We are all about the mustache and only the mustache," said Movember's U.S. Director Mark Hedstrom. "What we're asking them to do is participate by changing their appearance. What that fosters is a conversation."
From there, Hedstrom said men can explain why they're growing a mustache and start talking about men's health.
Now, it has campaigns in 21 countries, according to the organization. This year, the U.S. Movember campaign will also include men's mental health and men's fitness, Hedstrom said.
What is No-Shave November?
No-Shave November is a different organization that encourages people to donate what they would otherwise spend on hair grooming to the American Cancer Society.
Instead of being "all about the mustache" this group is a little more anything goes. Participants can grow mustaches and beards, but it also encourages women to maybe skip shaving their legs.
No-Shave November was founded on Facebook in 2009, but last year began a partnership with the American Cancer Society.
How can I participate?
To participate in Movember, start with a fresh face at the beginning of the month and "donate your face" until Nov. 30 by not shaving. You're like a fuzzy billboard for mean's health issues. You can raise funds, too. The Movember Project has donated more than 800 programs to date.
To participate in No-Shave November, give up one of your hair grooming practices and donate what you'd normally spend on it toward cancer research.
"Nearly everyone spends some amount of his or her hard-earned money on grooming, whether that's shaving, waxing, trimming or threading," according to No-Shave November's website. "If just for November, those individuals gave that cost (ranging from a few dollars for razors to a $100 salon visit) to a cancer charity instead, friends and family alone could pool together a sizable chunk of change to help cancer patients and their families."
Can't grow a mo'?
No problem. Not every man can grow a mustache, and that's OK.
"There's no such thing as a perfect mustache. Every mustache is perfect in its own unique way," said Adam Paul Cousgrove, the chief executive of the American Mustache Institute, which chooses an official Mustached Man of the Year annually. "They're the snowflakes of the face."
Women can participate in Movember by pushing the men in their lives to grow out mustaches and getting them to be active as part of Movember's new "Move" initiative.
"We're trying to practice what we preach," Hedstrom said. "Diet and exercise are key to a healthy lifestyle."
Or women can skip the salon visit (or leg shave or whatever) and participate in No-Shave November by donating that money to the American Cancer Society.
What do I need to know about prostate cancer?
Prostate cancer is one of the most common types of cancers in the United States with an estimated 233,000 new cases in 2014, according to the National Cancer Institute. That means it accounts for 14 percent of all new cancer cases.
An estimated 29,000 people will die of prostate cancer this year, according to the NIH, meaning it accounts for about 5 percent of all cancer deaths.
What do I need to know about testicular cancer?
The NIH estimates that 8,820 people will be diagnosed with testicular cancer in 2014, and 380 people will die from it.
What do I need to know about cancer in general?
An estimated 1,665,540 people will be diagnosed with cancer in 2014, according to the NIH. And an estimated 585,720 people will die of cancer.
What if I want to keep my mustache afterward?
You would make the American Mustache Institute very happy.
"We're here to show that the mustache is here to stay," Cousgrove said. "We're a hearty, ruggedly good-looking people."