Those numbers do not include testosterone supplements purchased over the counter or by mail. These herbs, vitamins, and natural supplements can be used to increase testosterone levels and help people coping with testosterone-related problems. It’s also a good idea to check if the supplement contains any ingredients you might be allergic to. And, of course, if you have any health condition or are on medication, please consult with your doctor first before taking any testosterone boosters. In short, natural testosterone boosters work on the symptoms of low testosterone.