Thorne's Iron Bisgylcinate is NSF Certified for Sport®. It is essential for the formation of red blood cells.* The U.S. Centers for Disease Control has determined that the prevalence of iron deficiency is greatest among toddlers (7% of those ages 1-2 years) and menstruating adolescent and adult females (9-16 % of individuals ages 12-49, whether they are athletes or not. Conventional iron supplementation, including forms such as ferrous sulfate, can cause gastrointestinal side effects – including nausea, vomiting, constipation, diarrhea, and dark-colored stools – because these conventional forms of iron are poorly absorbed. Thorne's Iron Bisglycinate provides 25 mg of elemental iron per capsule that has been reacted with glycine for optimal absorption in the gastrointestinal tract, thus helping to decrease the typical gastrointestinal side effects.*

An iron deficiency can manifest as weakness, fatigue, shortness of breath on exertion, dizziness, tinnitus, spots before the eyes, drowsiness, irritability, infrequent menstruation, and loss of libido.* Athletes need approximately 1.5 times as much Iron as non-athletes. Those who follow a vegetarian or lower protein diets may have needs as high as 1.8 times as much dietary iron. Blood loss from injury and muscle damage, as well as GI bleeding associated with extreme endurance activities can further decrease the body's iron stores.

Low iron can lead to a reduction in the body's normal uptake of oxygen to cells. A reduction of oxygen to cells can lead to a reduction in work capacity and aerobic performance. Untreated chronic low levels of iron can lead to iron deficient anemia.

Because an athlete needs to know that his or her supplements are trustworthy and compliant, every batch of an NSF Certified for Sport® product is tested for compliance with label claims and to ensure the absence of more than 200 substances banned by many major athletic organizations, including stimulants, narcotics, steroids, diuretics, beta-2 agonists, and masking agents.