Lysine & Cold Sore Prevention

Cold sores are itchy, fluid-filled blisters that can pop up with almost no notice, causing embarrassment and stress. An outbreak can be triggered by factors such as diet, weather and stress. In short, it sometimes feels like anything can cause a cold sore. If you're someone who is prone to frequent outbreaks, the amino acid lysine may well prove to be your best ally.

Lysine in Food

• Cold sores replicate using arginine, an amino acid found in many foods. Lysine is the antidote to arginine--it blocks the replication of the herpes simplex virus. One of the best things you can do to prevent cold sores is to make lysine a bigger part of your daily diet. Most fruits, vegetables and fish have high levels of lysine and low levels of arginine. Unsweetened, natural yogurt is one of the best anti-cold sore foods because of its lysine content. Be sure to check for gelatin in the ingredients, as some yogurts contain this arginine-rich ingredient that may actually cause an outbreak. Milk, cheese, beans and even ice cream all contain lysine.

Lysine Supplements

• You can also take lysine supplements: 500mg is a good start, although you can up that to 1,000mg or 2,000mg if you're someone who really struggles with cold sores. Look for a brand that includes zinc, vitamin C and bioflavonoids--these vitamins will help the lysine absorb better. Always take lysine supplements with food and a full glass of water to avoid an upset stomach. Avoid lysine brands that contain gelatin, which can trigger cold sores, and dicalcium phosphate, which can make it hard for the body to get nutrients like zinc.

Topical Creams

• A few topical creams and chapsticks containing lysine are available, but they may work better to soothe cold sores that have already broken out. Lysine creams can be pricey and may not prevent new cold sores. The only topical cream the FDA approves to shorten the duration of cold sores and possibly prevent outbreaks is Abreva, sold at most food and drug stores.