Dopamine is the neurotransmitter that is involved in your reward cascade. When people are risk takers, they typically have low dopamine. People who are more likely to worry and be careful, typically have high dopamine. But how does this play a role with testosterone.
These two chemicals are closely related. They actually run together, so to speak. As dopamine goes up, testosterone will go up as well. So if we analyze dopamine and find that its low in a person with low testosterone, then we can start to support the reward cascade. This can often bring testosterone levels back up as they follow the rising dopamine.