Become a Nutritarian Coach with our Certificate Program! Starts August 13, 2024!   VIEW DETAILS

Cold Sores

Cold sores (herpes labialis), or otherwise referred to as fever blisters as they commonly follow an infection, are caused by a herpes virus (herpes simplex type-1, most commonly) and are found on the lips and surrounding areas of the skin in someone who has been infected. Herpes viruses are contagious, usually acquired in early childhood, and once it has infected someone, it stays dormant most of the time in the local nerve cells until a breakout occurs.

  • Overview
  • Action Plan
  • Ask The Doctor


Cold sores are a very common and well known skin disease. It is estimated that close to 80% of the population carries the herpes simplex virus that causes cold sores (herpes simplex type- 1), with approximately 20% or more of them suffering with recurrent cold sores1 (on average 1-3 times per year). Cold sores are characterized as:

  • Being preceded by symptoms of burning, itchiness, tingling or numbness on the lip before breakout
  • Having a cluster of small blisters
  • Having symptoms of burning, itching
  • Being triggered by prolonged sun exposure, infection or fever, stress, hormonal changes
  • Being contagious during the first 3 days of having the sore
  • Usually lasting up to 1 week with each breakout

Although currently there is no cure for this chronic infection, and it is not clear as to why some persons get recurrent breakouts and other do not, boosting your immune system’s own ability to fight this virus can help reduce the risk of recurrent breakouts. A Nutritarian lifestyle is already optimized to increase the efficiency and strength of the immune system, helping reduce the frequency and duration of breakouts.

  1. Pica F, Volpi A. Public awareness and knowledge of herpes labialis. J Med Virol 2012, 84:132-137.

Action Plan


A Nutritarian eating style includes an abundance of immune-system boosting foods such as:

  • Garlic, onions
  • Mushrooms
  • Green leafy vegetables
  • Berries
  • Cruciferous vegetables
  • Peppers
  • Tomatoes
  • Many others

Besides following a Nutritarian eating style every day for prevention of breakouts, during a breakout, blending or juicing these foods as a supplement can further boost the important nutrients needed to help fight infection.

Zinc is an important nutrient involved in the immune system, and taking supplemental zinc 10-15 mg daily may be helpful to reassure adequacy (do not exceed 30 mg daily).

Although more studies are needed, some research suggests lysine (L-lysine), an amino acid taken as a supplement, reduces the recurrence of cold sore breakouts, if taken daily.1 Nuts and seeds should be limited to one ounce a day for a female and 2 ounces a day for a male to limit arginine, which antagonizes lysine.

Stress reduction

As stress, including lack of sleep, can be a trigger for a breakout, make sure to implement healthy sleeping habits and stress-reduction strategies, such as moderate exercise and meditation.

Find additional help

ONLINE: All members of can search the Ask the Doctor archives for discussions on this topic. Platinum and Diamond members can connect with Dr. Fuhrman by posting questions in the forum. Not a member? Join now.

IN PERSON: Book a stay at Dr. Fuhrman’s Eat to Live Retreat in San Diego, California. With options ranging from one, two and three months (and sometimes longer) you will be under Dr. Fuhrman’s direct medical supervision as you hit the “reset” button on your health. For more information: (949) 432-6295 or [email protected]

EVENTS: Join Dr. Fuhrman for an online boot camp, detox or other event. During these immersive online events, you’ll attend zoom lectures, follow a special meal plan, and have access to a special, live Q&A session with Dr. Fuhrman. Learn more about events.

  1. Griffith RS, Walsh DE, Myrmel KH, et al. Success of L-lysine therapy in frequently recurrent herpes simplex infection. Treatment and prophylaxis. Dermatologica 1987, 175:183-190.

Ask The Doctor

The following are sample questions from the Ask the Doctor Community Platinum and higher members can post their health questions directly to Dr. Fuhrman. (All members can browse questions and answers.)


I want to replace my husband’s rib-eye steaks, hot dogs, and cheese with healthier protein sources. He is fine eating beans, but he loathes nuts, as he typically gets cold sores when he eats them.

His doctor told him that nuts create a lysine imbalance or deficiency and to stay away from them and take a Lysine/Zinc/C formula as prevention which seems to work well.

Do you agree that certain nuts can create cold sores?


The most important thing is to eat healthfully and that means a diet with lots of vegetables, both raw and cooked, and much less animal products. Nuts and seeds have a high arginine to lysine ratio and have to be limited for many people with this condition who seem to be bothered by this. Nuts and seeds are too important and healthy a food to omit, so limiting them to just an ounce or two a day should be okay as long as he is taking lysine as a supplement.


My husband and I have been following a Nutritarian diet for a year and have been happy with many different results. Our 19-year-old daughter suffers from frequent herpes/cold sores on her lip. She eats fairly well but still suffers from these outbreaks. Prescription medicine does not seem to help her very much. Of the available supplements, which ones truly work and at what dosage?


With superior nutrition, we see reduction of breakouts over time. Focus on the entire Nutritarian diet, especially GBOMBS (Greens, Beans, Onions, Mushrooms, Berries, and Seeds) to improve her immunity, which can reduce the number of outbreaks. Besides the flax seeds and/or chia seeds, she should not eat other nuts and seeds to keep her arginine/lysine ratio low. She can also try taking lysine 600 mg. twice daily. My Women’s Daily Formula + D and DHA/EPA Purity would be beneficial. The Immunotect supplement has plant extracts that boost immunity and will most likely help as well.


I have read that supplementation with approximately 1200 mg/day of lysine is effective for oral herpes prevention, and double that amount is helpful during a cold sore outbreak. I would like to hear your opinion as to whether this amount of lysine supplementation is safe.


The evidence is limited for cold sores but interesting. The little bit of evidence we have on the safety of lysine suggests that those with kidney problems shouldn’t be using it regularly at high doses, but otherwise it is well tolerated by most everybody else at 1000-2000 mg. daily on an ongoing basis.