I personally think there are much better options now then clen.. for example a SARMS run, or using GW-501516.
Clen should be ran 2 weeks on and 2 weeks off.. during the 2 week on period, you will want to bridge the dose of clen, to see what your body can handle with the max dosage being 160 mcg per day. Clen will shut down your beta 2 receptors quickly, this is why you should only run it 2 weeks at a time. Taking benadryl at night will help your receptors as well as help with any insomnia problems that occur. Clen will deplete your liver of taurine and is known for causing pretty bad cramping, especially during exercise. Because of this supplementing with taurine is a must.. 3-5 g per day. Also make sure to drink plenty of water. Clen is can be very dangrous so make sure you are ready for it before starting.
You clen run should look something like this:
Day1: 40 mcg
Day2: 60 mcg
Day3: 80 mcg
Day4: 100 mcg
Day5: 120 mcg
Day6: 120 mcg
Day7: 120 mcg
Day8: 120 mcg
Day9: 120 mcg
Day10: 120 mcg
Day11: 100 mcg
Day12: 80 mcg
Day13: 60 mcg
Day14: 40 mcg
You should only increase the dose if the side effects are tolerable. I would stop at a maxium dose of 120 mcg because you have never ran this before. Remember, be safe.