ECA can be a great booster. I used it this way for a very long time and I can say it is the best for this, much beter than Clen, b/c clean will give u shakes much worse than ECA will(if any, none for me).
This is great for consistent use for up to 6 weeks. but then after this on the days you don't take it, you'll be tired, and tend to eat bad and there you are . .back in the same spot you're were before you started.
I know this is how it is b/c I have gone through this many times. Without a doubt, if you keep using it, you will become more tolerant, and will have to take more and more to get the same boost.
This can be combated by 2 strategies:
1) Do a 30-45 days cycle with a tapering up and down. Start slowly, and take ONLY what u need to get u into the gym. If you're using 25mg of Ephedra HCL, split the tabs in half and bump up slowly this way. Also, use Caffeine(natural source like guarana, which has a slower digestion, and will last longer in your system than pure caffeine), and asprin. Ratios of 1:10:10 (E:C:A). Make sure in your last 15 days taper down. Reduce your intake/day by 1/2 tab. Stay off of it for I'd say 14-30 days.
2) Take benedryl to upregulate your beta-2 receptors. Take 50-100mg of benedryl before bed 2 nights in a row every 10-14 days. This cleans your receptors and will allow you to get the ECA effect for longer.
Once thing I will mention is that if you're using it for only a boost. I would suggest drinking a double shot of expresso/strong sup of coffee 20-30 min before you want to be in the gym instead of using ECA EVERYTIME. Perhaps bounce back and forth or something By the time you're driving, you'll have enough pump to get you on the first machine in the gym, and then once you're there . . .you're there.
Got to ask yourself .. do you plan to take ECA for the rest of your life to get you into the gym? I hope not. I think it is wise to use this in the meantime, but REALLY try to find some alternative methods to get you in the gym. Coffee is easily accessible and works well.
I like guarana b/c the buzz from the caffeine is longer and much less intense, it's more of a stable and longer type of buzz. I buy it on ebay in bulk powder, and slam it with a diet coke.
I am in the same boat using the stuff, but for appetite suppression(which is how I REALLY think ECA helps people lose weight). But I ask myself that same question, and I know it's not in my best interest to use it until I'm 80+. I'd probably die.
Good Luck,
Mr. BEEF