Is there a way to slim down your neck?

So I have genetically a 17.5 inch neck and I hate it. There is no fat around my neck it's all muscle. So is it possible with a lot of training to slim down my 17.5 inch neck to a 16 or 15.5 size? I found some websites where it says that muscle mass can shrink. I also found something called HRT which also shrink the mass of the muscles in your neck, but HRT is only for transgender people and I'm not. I really want to lose at least 1-2 inches from my genetically neck muscles.

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