One of the most popular supplements associated with cold sores is L-Lysine. Your pharmacist may have even recommended it to you already. The idea is that it works by retarding the growth of the virus and inhibiting viral replication. You may have also been told to increase foods high in L-Lysine and reduce foods high in L-Arginine.
This may very well worked in lab conditions. But did it work for me? Unfortunately no. I've taken up to 8000mg a day (out of desperation) and have also applied it topically with a hope and a prayer. I've experienced no benefit in frequency or duration of outbreaks.
So why does this supplement seem to work so well for some individuals and not others? I'll get to that in a bit, but first let me give you a brief background about L-Lysine.
It's an amino acid that forms part of all the proteins in your body and is critical to your health. It is a macronutrient which your body cannot produce, so you need to include it in your diet. Studies have shown that L-Lysine is vital for proper immune function and I think this is the main reason some people may have a positive result when supplementing with it. I believe these people may not be getting adequate amounts of the amino acid in their diets, causing their immune systems to run less than optimally which sooner rather than later results in an outbreak.
Should you take this supplement? Some would say if you not getting enough in your diet, then yes. I however on the other hand say no, it's a complete waste of money. Not because it's toxic and there's probably not much harm in taking it. But it is really easy to get adequate amounts in your diet by just eating properly! With the correct diet we get so many other nutrients all which have a knock on effect at improving our health. Our immune systems are very complex and unfortunately singling out one nutrient as the silver bullet is not the answer especially when we don't fully understand how everything works together synergistically.
Bottom line, if L-Lysine does work for you have a good look at your current diet and see if you need to make any changes. If you don't see results, don't worry. Please don't start drastically changing your diet. You are probably getting enough L-Lysine, any more just won't have an affect. Increasing your L-Lysine whilst reducing L-Arginine could also end up making things worse. We need both of these amino acids to support a healthy immune system. It's all about balance.