Anti-Estrogens
Most people have heard of Anti-E's due to their role in a person's steroid cycle. Anti-Estrogens are used to prevent gynocomastia (the formation of breast tissue) from steroids that aromatize and also reduce water retention. However, Anti-Estrogens can be also used for a host of other reasons, and in our case, fat loss. Estrogen is a "fattening" hormone, and if it is kept in check while dieting you can receive a hard look without even using anabolic steroids. If you don't believe me, notice the body fat gain when a girl starts using birth control, this is caused by the increase in estrogen levels.
The best drugs for this effect would be Nolvadex (if you are not using anabolic drugs), or the much more powerful (but also very expensive) Arimidex and Femara. Dosages of Nolvadex are usually between 20mg and 40mg a day, Arimidex is usually 1/2mg to 1mg a day, and for Femara, one 2.5mg tab could be used ED or EOD. These could all be used by them self but you could stack Nolvadex with Arimidex or Femara due to the fact that Nolvadex and Arimidex both effect estrogen in the body differently.
These are very good for the natural dieter due to the fact that they will give you a hard (steroid) look, and they will also allow you to retain more muscle mass while dieting. For someone using Anabolic drugs during a fat loss cycle, they should be used regardless because of steroids aromatizing into estrogen, and also they will keep water down and give you a "dry" look.