I mostly prefer Arimidex while on a cutting cycle. This drug is strong and very effective yet a little more forgiving that letro. Letro is stronger and less forgiving. It is easier to take too much and end up with very low estrogen. We want to control E, but we do not want to wipe it out. We want to have enough E to keep from getting side effects like dry and painful joints but enough to keep estrogen in the lower normal range, so that you are in an optimal fat loss state. 

For the off season, I like arom, but it seems to require a little more to be as effective. So thats a good reason to save it for off season cycling. Plus it does not have a negative impact on cholerterol

You can use letro. Its just that you will eed less. I would give a try to 1/2 tab GP Letro taken 2x wk. Then if needed you can always incrase 

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