Vitamins increase testosterone naturally. Herbs increase testosterone, research has shown. Testosterone decreases as we age, but numerous herbs and nutrients can help increase the blood levels of this hormone. Low testosterone can increase the risk of heart problems as well as depression, osteoporosis, and dementia. Reduced testosterone causes a condition known as andropause that develops with aging. Testosterone is an anabolic steroid and research on synthetic hormone replacement has been inconclusive.