yes I worded that wrong.
I meant, the entire "beleif" behind 1-MT is that its basically a precusor to testosterone, and that the body will convert it to testosterone, this of course would have negative impact on HPTA via feedback mechanisms, but if it IS testosterone, then it will aromatise, and the more test there is the more estrogen there will be.
Also something interesting to point out here, if you've ever heard of Proscar/Propecia and Avodart, drugs that stop DHT conversion, if you take these you increase ur lvl of testosterone thus increasing the lvl of estrogen, not to mention the loss of DHT androgens, taking one of these can make you more susceptable to gyno and other estrogen side effects. Same goes weith takin letrozole solo, the less estrogen, the more test to convert to DHT, thus increasing androgen side effects such as male pattern baldness, and prostate enlargement to name some.
So ideally, youd want to take letrozole and avodart together, then also use a DHT derivative steroid (trenbolone or masteron) otherwise you could end up 'shitty-muscles' from lack of DHT (potent androgen)... and we all know DHT results in rock-solid muscles.