Hello, I've been reading and watching a lot lately and to be honest more I read and more I'm confused.

I'm 42yo, 172cm tall and 71Kg, I've started really late the gym, I was little bit overweight (78-82 Kgs) and sedentary until 37yo, when suddenly I've decided to do sport and gym.

Now I've been training for years, I've been measuring my food (I've literally years of records of food/macros intake between MFP and Fatsecrets) and myself. Now I workout once or twice a day I have a decent body, but I'd love to gain another 5-8 Kgs of muscle. I've tried with different PTs (natty) but it seems that I can't go over 71-72kgs, if I eat more (as people suggested multiple times) I get belly instead of muscle. I've tried to alternate bulk and cut phases but at the end I return always at 68-71Kgs

I can't really complain about my body, I'm more fit than 99% of my friends (same age or younger) but I'm still not happy with the current situation. I'd love to reach the 75/76kg of weight.

For what I read 5KGs of gain should be an "easy" target to obtain with PED but I've also read that I should know what to do or at least I should talk with someone expert. I'm not an expert, I don't really understand where to start or what to buy, and I don't know any person that is in the PED world.

I've found them: https://insidebodybuilding.com but I don't know if they are legit and I don't want to do anything stupid.

I'm really motivated, so if someone can point me to the right direction would be great or if someone knows a professional PT that can guide me would be great too. I live in Watford near London.

Feel free to contact me in private.

Thanks in advance!

EDIT: thank you everybody for the answers and the messages. They were really helpful