Great stamina and endurance is heavily dependent on ensuring normal healthy blood flow. As we age, circulation begins to decline for many. Two supplements that are popular for people who want to support normal circulation are the amino acid l-arginine and the herb maca. Our formula includes a high-potency dose of each of these two important nutrients together in one formula. Chronic stress sometimes includes the restriction of blood vessels. Maca has been used in traditional medicine for centuries and like other well-known adaptogenic herbs, may help the body fight the effects of stress. Meanwhile, l-arginine signals the body to produce a compound called nitric oxide which is responsible for causing the blood vessels to expand; this allows for greater blood flow throughout the body. All Mason Natural products are produced in a GMP certified facility and laboratory tested for purity.