Age doesnt really decide when you should start with steroids. ( not that you should) But its your peak. Like I said the first 4 years their is no real point to it. I dont know if you saw earlier but I saw my first cycle would probabaly be in 3 years if I decided to use. Not because I will be 24-25 but thats how long I should able to build muscles without gear.
Regarding the severe Acne. You are going to get that must likely even if you wait until 24.
I have not seen one single study that says steroids halt bonegrowth. If you are using bad HGH you can mess up your bonegrowth. I have heard stories of guys getting 1 arm longer then then other. Its the same myth as if you lift weights at a young age you will stop the natural growth. Their are no studies which have proven or disproven that hypothesis.
(Sidenote: Arnold started at 13, not that human bodies can really be compared but its a funny fact).
Doing a cycle for cutting at 21 with low doses shouldent have any severe side effects but that doesnt mean the young guys on here shoud do it. I know alot about steroids but im still waiting for my time. I havent reached my Peak.
Regarding your Cycle, if its not to much Would you mind telling me your cycle? Im intressted in knowing the prices in Pakistan if you have the knowledge regarding that. Just pm if you dont want to post it public or dont do it if you dont want to talk about it.