A natural decline in testosterone can negatively alter the balance between testosterone and estrogen, leaving you with an imbalance of hormones, which can have a dramatic effect on your overall health and well-being. You may experience symptoms such as increased weight gain, chronic fatigue, low sexual desire, moodiness, and loss of muscle mass. If you're experiencing any of these symptoms and you need a boost in your vitality and energy levels so you can feel young again, you're going to want to increase your testosterone production. Here's how.