The opposite of excessive dosage is of course inadequate dosage. If a steroid is under-dosed then the effects of the product will likely be negligible. That is why many bodybuilders combine multiple different steroids.
Using several steroids in the same timeframe, athletes can use weaker doses of each product and so avoid the degradation of receptors and thereby limit any side effects.
The other important consideration about the use of steroids is the “cycle”. This is the period of time during which the athlete takes a steroid. Most cycles last typically between 8 and 12 weeks, then the athlete begins a “post cycle” period of generally around 3 months.