A West Australian documentary has lifted the veil on what it means to transition from female to male, tracking the journey of four Perth trans men as they manoeuvre through the challenges of switching gender.

The film It's Not Just Me, from Australian director Jonathan Messer, was four years in the making and followed each of the men for differing amounts of time throughout their journey.

Simon (R) with his brother when he was a child named Sophie. ( Supplied: 'It's not Just Me' )

Simon, who was named Sophie, began his transition two years ago, with six months of that time period filmed for the documentary.

He said while he was impatient to become a male, having always identified as that gender, but it was much harder for his family and his friends to accept.

"My family — they didn't take their child transitioning all that well," he said.

"It was hard for them to understand and to come to terms with it.

"I just wanted to tell my story to maybe help one other person out there or help their family just to understand the situation a bit better."

Simon, now 27, said for the first time he felt like he could truly be himself.

And despite breaking up with his previous girlfriend before filming finished, the maintenance officer at the RSPCA said he now had the most supportive partner — and his family had also come around.

Simon's passport showed his birth name as Sophie. ( Supplied: 'It's Not Just Me' )

"My dad needed a bit of time to kind of settle into it, having a second son and seeing me for who I truly am," he said.

"At the beginning of my transition I thought I was actually going to lose him.

"But he's probably the most supportive person in my life now — aside from my girlfriend."

But he said for others it had never been resolved.

"I've known of people that have really struggled with their family, they've been abandoned by their family or they're just been told that they're sick," he said.

"I was also told I was sick.

"At the end of the day people have their own opinions and religions and beliefs and whatever else and that's absolutely fine.

"But I'm not upsetting anyone by being who I am, it doesn't matter, I'm just being me, and I think everybody in the world should have that freedom to be who they want to be — we're all human."

No transgender men in popular culture

Jonathan Messer wanted to shine a light on the lives of transgender men. ( ABC News: Briana Shepherd )

Director Jonathan Messer was born in Victoria, but after working in the film industry around the world he now calls WA home and is currently undertaking his doctorate in philosophy as a PhD candidate at the Western Australian Academy of Performing Arts.

He said the idea for It's Not Just Me came about from wanting to look at the rising acceptance and understanding of transgender women.

"When I was doing my literature review I looked a little bit deeper and I realised actually there are no men in popular culture — transgender men — and so I thought I'd explore that," he said.

He said he had been surprised to find quite a strong trans men culture in Perth.

"There's a very strong network here in Perth of transgender men, which is kind of a secret," he said.

"It took me a very long time — there are a lot of gatekeepers — but finding four amazing individuals who were willing to tell their story — all very articulate, very kind, very genuine — was a godsend."

He said watching the changes in each man from the hormone injections was fascinating — with their personalities changing along with their bodies.

"You see that also in the film along with their relationships breaking down in some cases," he said.

"That was complex for me to watch — seeing people change and grow apart.

"But it's also the partners of people who have to transition."

The film also follows David — a retail worker and self-confessed nerd — for a year, while Logan uses a GoPro and self-records four months of his journey, and Max was followed over the course of a single day.

Mr Messer said the film had become less his and more about the entire team.

"The four guys in the film tell their story and I just helped them," he said.

"But what I think comes out of it is something really beautiful."

He said the message of the film was simple.

"It's not easy for everyone and that's the message of my film — you are not alone, It's Not Just Me," he said.

"I hope people would leave the film just seeing that people are just people."

The film has its Australian premiere at the Revelation Film Festival in Perth on July 16.