Hey bud do as you please, but my cousin started cycling at your age and is now already on TRT for life at age 27, so I would put a lot of thought into what you're doing. It can be an extremely tempting choice I know, but it is really worth the long term problems you may have to deal with?
It def hardens you up, for me it didn't give quite winstrol like results, but got me hard and gave a great strength boost. S4 is slightly suppressive so I'd run a pct. If you're cutting stacking it w GW and MK2866 is awesome.