Lysine supplement benefit, does it prevent herpes?
October 2 2016 by
Ray Sahelian, M.D.


L Lysine is an amino acid that contains two amino groups, neither of which can undergo direct transamination. L Lysine is degraded by a complex pathway in which saccharopine, alpha ketoadipate, and crotonyl CoA are intermediates. Ultimately lysine generates acetyl CoA for the production of energy.



You can find l lysine capsules and powder as supplements.


Life Extension, L-Lysine, 620 mg, 100 Veggie Caps
purchase L-Lysine supplement, Source Naturals

L-Lysine is an essential free-form amino acid which acts as a precursor for other amino acids, including L-carnitine (needed for fat metabolism). It is crucial for the formation of collagen, a major part of the body's connective tissues. It also contributes to energy production when converted to acetyl coenzyme A, one of the principal fuels for the Krebs cycle.

Supplement Facts:
L-Lysine (HCI) - 1,000 mg
Suggested Use: One lysine tablet daily, or as recommended by your health care professional.

Purchase Lysine supplement


Lysine and herpes simplex

At this point, it appears that some studies show lysine to be helpful in herpes treatment or prevention, but several more studies are needed to confirm or refute these findings before we can make any firm recommendations for the use of lysine in herpes treatment. My overall impression thus far is that if lysine does help a herpes infection or if lysine prevents a herpes infection, its effects are most likely mild. Although the role of lysine in herpes has been studied off an on for quite a number of years, no firm conclusions can yet be made. I have listed some of the L lysine and herpes studies at the bottom of the page. The ideal dosage of lysine for herpes prevention is not known at this time and the long term side effects of lysine, if any, are also not known. Thus far no significant l lysine side effects have been reported in the medical literature.


J Psychiatr Res. 2014. L-lysine as an adjunct to risperidone in patients with chronic schizophrenia: a double-blind, placebo-controlled, randomized trial. Increasing evidence suggest that the nitric oxide signaling system of the brain may contribute to the pathophysiology of schizophrenia, making this system a target for development of novel therapeutics. The objective of this study was to investigate the efficacy and safety of L-lysine as an adjunctive to risperidone in the treatment of patients with chronic schizophrenia during an 8-week trial. Seventy-two chronic schizophrenia inpatients with a Positive and Negative Syndrome Scale (PANSS) total score of ≥ 60 participated in a randomized, double-blind, placebo-controlled trial in the active phase of their disease and underwent 8 weeks of treatment with either L-lysine (6 g/day) or placebo as an adjunctive to risperidone. Patients were evaluated using PANSS and its subscales at baseline and weeks 2, 4, 6 and 8. The primary outcome measure was to evaluate the efficacy of L-lysine in improving schizophrenia symptoms. Repeated measures analysis demonstrated significant effect for time treatment interaction on the PANSS total, negative and general psychopathology subscale scores but not the PANSS positive subscale scores. The frequency of adverse events (AEs) did not differ significantly between the two treatment groups and no serious AE was observed. The present study demonstrated that l-lysine can be a tolerable and efficacious adjunctive therapy for improving negative and general psychopathology symptoms in chronic schizophrenia. However, the safety and efficacy of higher doses of l-lysine and longer treatment periods still remain unknown.


Carnitine and L Lysine
Carnitine is synthesized primarily in the liver and kidneys from lysine and methionine. Carnitine covers an important role in lipid metabolism, acting as an obligatory cofactor for beta-oxidation of fatty acids by facilitating the transport of long-chain fatty acids across the mitochondrial membrane as acylcarnitine esters. Furthermore, since carnitine behaves as a shuttle for acetyl groups from inside to outside the mitochondrial membrane, it covers also a key role in glucose metabolism and assists in fuel-sensing. A reduction of the fatty acid transport inside the mitochondria results in the cytosolic accumulation of triglycerides, which is implicated in the pathogenesis of insulin resistance.


Clin Ther. 2012. Effect of lysine, vitamin B(6), and carnitine supplementation on the lipid profile of male patients with hypertriglyceridemia: a 12-week, open-label, randomized, placebo-controlled trial.H Fat metabolism is known to be altered in hypertriglyceridemia. Fat oxidation requires carnitine, which can be obtained either from the diet (animal or dairy products) or through synthesis in the body using both lysine and vitamin B(6). The goal of this study was to investigate the effect of lysine, vitamin B(6), and carnitine supplementation on both glycemia and the lipid profiles, specifically triglyceride (TG) levels, in men with hypertriglyceridemia. This 12-week, randomized, placebo-controlled clinical trial was conducted at a Lebanese medical center. A total of 85 hypertriglyceridemic (TG> 150 mg/dL) male patients were randomized to 1 of 5 groups and given supplements of lysine (1 g/d), vitamin B(6) (50 mg/d), lysine (1 g/d) + vitamin B6 50 mg/d, carnitine 1 g/d, or placebo for 12 weeks. The lipid profile (TG, total cholesterol, LDL-C, and HDL-C) and fasting plasma glucose levels were assessed at baseline and at 6 and 12 weeks. Adults (∼50 years) Lebanese males from a low socioeconomic status in Beirut were given the appropriate supplements. Vitamin B(6) supplementation was associated with a significant reduction in total cholesterol and HDL-C of ∼10%. In addition, plasma TG was reduced by 36.6 mg/dL at 6 weeks, whereas levels in the placebo group increased by 18 mg/dL; this difference failed to reach statistical significance. No major changes in the lipid profile were observed in the lysine and carnitine groups or when lysine was added to vitamin B(6). Vitamin B(6) supplementation in these male patients with hypertriglyceridemia reduced plasma total cholesterol and HDL-C concentrations.


L Lysine Research
Safety and effectiveness of an L-lysine, zinc, and herbal-based product on the treatment of facial and circumoral Herpes.
Alternative Med Rev. 2005. Singh BB, Udani J, Vinjamury SP, Der-Martirosian C, Gandhi S. Professor of Research and Senior Scientist, Southern California University of Health Sciences. Correspondence address: SCU Research Division, Whittier, California
L-lysine, an essential amino acid, inhibits normal replication of Herpes simplex virus (HSV), shortening the normal course and duration of the disease. This study was conducted to determine the effectiveness of a combination of L-lysine with botanicals and other nutrients in relieving the symptoms of facial and circumoral herpes. This small pilot study was conducted using an outcome (open-label) model. Thirty male and female participants (15 in each group) meeting the inclusion/exclusion criteria were admitted to the study. The 10 outcome measures used to monitor the sores were tingling, itching, burning, tenderness, prickling, soreness, bump/swelling, small blister(s), oozing blisters, and crusting, as well as before-and-after photographs of the lesion, and a daily diary. At the end of treatment the ointment produced full resolution in 40 percent of the participants by the third day and in 87 percent by the end of the sixth day. A cold sore episode may last up to 21 days without treatment. Overall data indicated significant improvement in participants by the sixth day of treatment for all but two participants. There were no adverse effects reported during this study.


Thirteen-week oral toxicity study of L-lysine hydrochloride in rats.
Int J Toxicology. 2004.
L-Lysine hydrochloride is an essential amino acid in humans and animals, and it is used in animal feeds, in prevention of herpes simplex recurrence, and cereal fortification in some developing countries. This study evaluated toxicological and behavioral effects of Lys during a dosing study with male and female Sprague-Dawley rats. The amino acid was incorporated into a standard diet at doses equal to 1.25%, 2.5%, and 5.0% (w/w). A control group of rats received a standard diet. All diets were administered ad libitum for 13 consecutive weeks. To examine stability of any potential effects, the administration period was followed by a 5-week recovery period, during which only the standard diet was provided to all animals. In male and female rats in each concentration group, treatment-related changes were not observed in the clinical signs, body weights, diet consumption, water intake, ophthalmology, gross pathology, organ weights, or histology. A Lys-related drop in serum concentration and an increase in urine excretion of chlorides was a compensatory reaction to the ingested hydrochloride. No functional, biochemical, or histological changes in renal function were found. The no-observed-adverse-effect level (NOAEL) for Lys was estimated at 5% for both genders.


Success of L-lysine therapy in frequently recurrent herpes simplex infection. Treatment and prophylaxis.
Dermatologica. 1987. Griffith RS, Walsh DE, Myrmel KH. Department of Medicine, Indiana University School of Medicine, Indianapolis.
A double-blind, placebo-controlled, multicenter trial of oral L-lysine monohydrochloride for the prevention and treatment of recurrent herpes simplex (HSV) infection was conducted. The treatment group was given L-Lysine monohydrochloride tablets (1,000 mg L-lysine per dose) 3 times a day for 6 months. A total of 27 (6 male and 21 female) subjects on L-lysine and 25 (6 male and 19 female) subjects on placebo completed the trial. The L-lysine treatment group had an average of 2.4 less HSV infections, symptoms were significantly (p less than 0.05) diminished in severity and healing time was significantly reduced (p less than 0.05). L-Lysine appears to be an effective agent for reduction of occurrence, severity and healing time for recurrent HSV infection.


Lysine as a prophylactic agent in the treatment of recurrent herpes simplex labialis.
Oral Surg Oral Med Oral Pathol. 1984.
This study examined the efficacy of long-term prophylactic lysine supplementation. Twenty-six volunteers with a history of frequently recurring herpetic lesions completed a 12-month double-blind crossovers study. The experimental group received daily oral supplements of 1,000 mg 1-lysine. Serum samples were analyzed at scheduled intervals. In most instances, members of the lysine group reported significantly fewer lesions than the control group. Similarly, those who were taken off lysine supplementation generally showed a significant increase in lesion frequency. Quantitative hematologic measurements revealed the most clinically useful relationship. Data from this sample population indicated that when a person's serum lysine concentration exceeded 165 nmol/ml there was a corresponding significant decrease in recurrence rate. Conversely, the frequency rate increased significantly as concentration levels fell below 165 nmol/ml. These results suggest that prophylactic lysine may be useful in managing selected cases of recurrent herpes simplex labialis if serum lysine levels can be maintained at adequate concentrations.

Q. i wonder if you have any thoughts on this problem my daughter suffers from a recurring herpetic problem which in the past has responded well to lysine. however as the mother of a 23 month old baby boy  who is still breastfeeding only at night - is it still the case that lysine should be avoided.
  A. We have not seen much research regarding the use of lysine during breastfeeding. It would appear to be safe, but we can't be for sure.

Q. Can lysine be taken the same day as dmae bitartrate, tongkat ali, choline bitartrate, or saw palmetto?
   A. I don't see why not.


Q. I have recurrent cold sore problem and want to use l lysine to prevent it. How effective is lysine for cold sore problem?
   A. Some of the research regarding the amino acid l lysine and cold sore infection appears to be promising, but a few more longer term trials would give us a clearer idea.


Q. I read on a website that food high in lysine such as yogurt or cheese can help with cold sores. Is that true?
   A. I have seen such claims regarding foods high in lysine and low in arginine as being beneficial for cold sore prevention, but have not seen such research. At this time I am skeptical of this approach. I think it is not worthwhile to change the type of food you eat just for the sake of potential herpes prevention. It may be too much effort for little or no benefit. It would be much easier to give a l lysine supplement a trial for a few months to see if it helps with herpes recurrence prevention. Just monitor your herpes outbreaks and document them to see if the l lysine capsule made a difference.


Q. Is there a benefit to L Lysine supplement use besides potential herpes prevention?
   A. I don't know any other reason to take it besides for herpes.


Q. I am prone to cold sores and take 1,000mg of lysine a day. Can I also take arginine (a lower dose than lysine at 500mg) for its effects as well without
increasing the possibility of an outbreak? Is that even enough arginine via supplementation?
   A. We don't know what affect the arginine combined with lysine will have, if any.


Q. I have found Lysine useful for keeping herpes suppressed and have been taking 1,000 - 1,500 mg a day for some years. I tried the Source Naturals Lysine. Although the 1,000mg dose is convenient, I find the capsules not only very large, but they have sharp edges and a relatively course surface - all of which make for difficult or even slightly dangerous-feeling swallowing. So, I have to look for another source of Lysine.


Any information on taking L-lysine 2-4 hours after a person takes the arginine to reduce the likelyhood of herpes outbreak?
    I have not seen any studies on the role of lysine supplements taken before arginine in terms of herpes outbreak.


In one of your articles you indicated that you did not know of other uses for l-lysine other than herpes. Well three time Nobel prize winner Dr Linus Pauling proved in his laboratory that high doses of L-lysine and vitamin C cleaned the plack out of your arteries and if you add Proline the effect is done quicker. Go to the Vitamin C foundation on the net they have the data. I have been taking their supplement for over a year and it lowered my blood pressure in addition. thought you should know. My cat had a candida infection in his eye, 500mg of l-lysine each day cured it in one week.
    I have not seen any long term formal studies in humans regarding the claims you mention. Was the candida in the eye of the cat proven by testing? Many infections clear up on their own. I appreciate anecdotal information but prefer that they be replicated by others or in a formal investigation.


I would like to take L Arginine to enhance the production of Nitric Oxide, but the last time I took it, I came down with Herpes. I understand that 5gs of L Arginine or more sometimes activates the Herpes Zoster virus. I also understand that taking L Lysine helps neutralize that affect. I took the 5 g for several weeks and then had Herpes along the back and ribs for the first time.My question is, if I take 5 g of L Arginine and 5 g of L Lysine together, will the L Arginine still enhance Nitric Oxide and would the L Lysine prevent the Herpes Zoster virus from utilizing the L Arginine for reproduction? I have Googled these questions and can't seem to get a specific answer. I'm sure many people have wondered this besides me, since it seems that most of my friends are familiar with the relationships of these two amino acids and Herpes.
   We have not seen any studies that address this quesiton.