Hey bros, my wrists are way smaller than the rest of my arms, and it looks stupid, I hate it to the point that sometimes I wear long sleeve sport coats to work out at the gym, how can I fix this stupid problem?
Unfortunately you can't change your bone structure. Your bone structure is determined by your genetics. That is why some people are 5'8 and some people are 6'2. So drug, supplement or steroid will make your wrists bigger.
Your forearm muscles extend from your elbow into your wrists. Having large forearms will make your wrists appear slightly larger. Start doing wrist curls and reverse wrist curls on your arm workout days to train your forearms. I would do 4 sets of each, 8-12 reps per set.
This is something determined by the genetics. Look at Donald Trump - he also has small wrists, but even he with all of this complexes and money can not solve this issue. Therefore, your best alternative would be to learn to live with it, rather than try to change something that can't be changed.