L-Serine is a Food for Special Medical Purposes for use under medical supervision. A powdered form of the amino acid L-Serine. For use as a supplement in the dietary management of conditions requiring additional L-Serine. e.g. inborn errors of serine biosynthesis such as 3-phosphoglycerate dehydrogenase deficiency and 3-phosphoserine phosphatase deficiency. Suitable for use from birth. For use under medical supervision.