Lamberts L-Histidine is a pure, free-form amino acid that is easily absorbed by the body without needing to be broken down by digestive enzymes. This product is manufactured in the UK in a factory that adheres to pharmaceutical GMP standards. Each capsule provides a full 500mg of L-Histidine HCl. Histidine is considered a non-essential amino acid for adults, and dietary sources such as meat, fish, and dairy products likely account for most of the total found in the body. Histidine plays a role in the regulation and utilization of several essential trace minerals, including zinc, copper, manganese, and iron. It is also involved in the formation of red and white blood cells. Take 1 to 6 capsules daily.