go for the Winny and drink it, if you are affraid of needles
Forget the Clen, it's just not worth it.
But if you do, take between 8-12 tabs a day and spread them. Try to take the last ones around 4 p.m., so you will be able to sleep at night. Remember max 18 days then a few weeks off. During the 2 weeks off, your friend can get depressed again, because he is returning to normal fat status. Clen can help for zeroing down like for a contest, but in normal life there is not much point in it.
You can expect accelerated heart beats, shaking hands, body temperature raising.
I include a URL where they say to take this for about 8 weeks, but remember your body gets used to the stuff.
Also you cannot compare Winny with Clen. Clen is not a muscle builder, but your dog can grow on it.