Found this info from another forum... --
Take clen every 3.5-4.5 hours that you're awake, stopping early enough to still be able to get to bed. Clen can, in some people, cause insomnia (and as with all stimulants, can cause anxiety in some).
Clen is a very effective repartitioning agent, and this is what it's most often used for. This means that it will increase your ratio of Fat Free Mass (FFM) to Fat Mass, by decreasing your Fat and possibly increasing your FFM. In one study, horses given a semi-reasonable dose of clen (slightly over 1mcg/lb x2 a day) and excercised for 20mins, 3x a week, had significant decreases in %fat (-17.6%) and fat mass (-19.5%) at week 2, which was similar to Clen given to horses who didn't excercise; however, the excercised group had a different FFM response, which significantly increased (+4.4%) at week 6. Week 6! Clen and clen+excercise produce roughly the same results for the first 2 weeks! The old 2 weeks-on/2weeks-off schedule is officially dead and buried. If you want the quasi-anabolic effect from the clen, it'll take more than 2 weeks on (6 weeks apparently). And in fact, since clen alone is similar to clen+excercise for those first 2 weeks...why would you ever use a 2on/2off protocol? Keep in mind that animal responses to beta-agonist/antagonists differ a bit from ours but you get the picture.
eg of a cycle-
1 clen 20/40/60/60/80/80/100
2 clen 100/100/100/100/100/100/100
3 clen/ben 100/100/100/100/100/100/100
4 clen 120/120/120/120/120/120/120
5 clen 140/140/140/140/140/140/140
6 clen/ben 140/140/140/140/140/140/140
7 clen 120/120/100/100/80/60/40
Proper dosing of clen are the same for both men and women. You'll need to take 20mcgs upon rising, and then repeat that same dose again later in the day, and then once again in that day (if you find you can tolerate the effects). So you'll start with 20mcgs, and then repeat that dose 2 more times that same day if you can tolerate it (side effects will determine this at hand shaking, sweating, etc. classic stimulant sides). Then you can start increasing the dose gradually. In my opinion no more than 200mcg/day. 60-120mcg/day is an average dose. And keep your Blood Pressure at (or under) 140/90, while on clen, just to be safe. If you go over that, lower the dose.
Bear in mind that clen isn't great for your heart, and can cause some issues there (enlargement of ventricles, etc) but most studies showing clen to cause heart problems are with animals, and even though the dosing is almost similar to what humans take (in some studies its within range of what would be double of a large human dose...) it's important to remember that animals have more beta-2 receptors and they cause certain event chains that humans beta-2 receptors may not. Clen causes cardiac hypertrophy to some degree, in some cases. Again though, many studies showing more significant heart problems are with mg dosing. We humans take clen in mcg doses.