It might be best/safest to shoot for moderate increases in T rather than huge increases as ollinger suggests. There is no telling how you might throw off the balance of hormones and other chemicals in your body with large increases of T. The "normal range" of T for men is actually rather large. According to some sources, a normal reference range might be 300-1200 ng/dl. Our levels vary throughout the day and also throughout our lives (decreasing with age). T levels are usually highest in the early morning (I wonder if this has anything to do with "morning wood").
The real "bad boy" in the testosterone family is DHT (DiHydroTestosterone). High levels of DHT appear to be a major factor with prostate enlargement & prostate cancer, male pattern baldness and possibly other maladies. According to one source that I came across, men normally convert about 6-10% of their T to DHT. So it would follow that increasing your T levels would probably also increase DHT levels. Since it is normal to produce some DHT, there may very well be some positive benefits that it has in the system. However, problems appear to arise when DHT levels get too high. With excessive DHT levels we will often see baldness or prostate issues.
The enzyme, 5α-reductase, is responsible for converting T to DHT. There are some pharmaceuticals on the market that inhibit the 5α-reductase enzyme, thereby reducing the amount of DHT in the body. There are also various foods, nutrients and herbs that tend to inhibit this enzyme as well. Some nutrients that can inhibit the enzyme include copper, zinc, and, possibly, selenium. Will mention other inhibitors in a future post.