I want to start a cycle of dinaboltz 10mg 2 tablets a day for 10 weeks i want to increase the muscle size to my arms and chest, what precautions should i take before taking these tablets?? what are the side effects? will they shrink my penis and balls,ect

Its not good to stay on D-bols for more than 6 weeks it can do some serious damage to your liver and a straight D-bol cycle isn't a great idea your best to toss some test into the mix.

as already said, your penis wont shrink, but your testicles might.. but be aware they dont shrink away to nothing, they only will get slightly smaller, and will regain normal size over time after you come off the cycle. PCT will also help regain your bodies balance after your cycle.

I also wouldnt reccomend only working out chest and bicepts, you will look out of proportion, you will need to work the rest as well to look right..
and remember legs is most important if you want a big upper body, as when working legs you release most growth hormomes!

You penis won't shrink, but some men's testicles shrink, because they're not producing testosterone. It's not permanent however, and once they're producing testosterone, you'll probably notice an increase in size.

You should do some research into steroids. I get the impression you're not training seriously, but I'll help anyway. When you're taking the steroids, you should be taking Estrogen (the female hormone) blockers and a liver support supplement like Milk Thistle. The estrogen will give you man boobs, and the milk thistle is to stop the steroids doing damage to your liver. The research will help determine if you have the right steroids, and also if they're actually real.

Also, when you've finished your cycle of steroids, you should start PCT (Post Cycle Therapy). You should take a testosterone booster (Biotest Alpha Male for example), and an continue with the Estrogen blocker.

If you skip PCT, the lack of testosterone and increase of Estrogen will LITERALLY strip ALL of the muscle you've gained. I can't stress how important PCT is.