Testosterone gels and patches provide a constant level of hormone and are applied once daily. These are applied to clean and dry skin on the back, shoulders, upper arms, abdomen or thighs. Care must be taken taken and they should not be applied directly to the genitals. Moreover, you should avoid them on dry, broken or irritated skin. Andro 400 Reviews While synthetic pills have similar effects and benefits, they can also have side effects like testosterone injections or shots. Natural pills are a better option to enhance testosterone levels. The essential difference is that while synthetic pills are a replacement therapy, natural pills are simulators that help increase your body's own production of testosterone.