Long-term use of supplemental lysine - is it safe?

The amino acids lysine and arginine have been shown to respectively inhibit and stimulate herpes simplex virus (HSV) replication. Lysine supplements have been used over the last three decades to inhibit viral replication, shorten the duration of herpetic blisters and help prevent recurrence. However arginine has many physiological roles in the body and as it uses the same intracellular transport routes as lysine there is the potential for adverse effects due to a relative arginine deficiency. There is also the potential for adverse effects on renal function due to increased amino acid intake.