Maca is a root vegetable and medicinal plant native to the Andes in Peru. It is safe for humans and animals to eat and has been used in Peru long before the Spaniards conquered the area. Ancient warriors used maca to keep their bodies energetic and vigorous while in battle. It can be high in iodine, so excessive consumption can lead to thyroid problems. Maca supplements are used to treat sexual dysfunction, increase stamina, improve physical and emotional wellbeing, and promote mental clarity.