One Direction and Shawn Mendes songwriter Teddy Geiger is transitioning

Songwriter Teddy Geiger says he is transitioning from male to female.

The 29-year-old has written huge hits for Shawn Mendes and One Direction and says he's at the "start of the process".

He decided to go public after a fan asked him why he looked "different lately".

Replying on Instagram, he said: "Love it or hate it, this is who I have been for a looooong time."

This is Teddy's Instagram post where he revealed he was transitioning.

Teddy says he "started talking about it with a couple of my close friends and family about a month ago and it's given me the courage to start the process."

He goes on to say that "the next step is to tell y'all".

Teddy's written songs that have sold millions of copies around the world - including Stitches, Treat You Better and Mercy for Shawn Mendes.

He also wrote Where do Broken Hearts Go for One Direction and has also worked with DJ Snake, Tiesto and James Blunt.

Before he switched to writing, Teddy performed as a solo artist

Shawn Mendes has written to support Teddy, simply saying "love u" on his Instagram post.

And he's not the only one.

Teddy's original post has had more than 16,000 likes.

Teddy's new post: "Woke up to so much love."

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