This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognizing you when you return to our website and helping our team to understand which sections of the website you find most interesting. We do not share any your subscription information with third parties. It is used solely to send you notifications about site content occasionally.

Herpes simplex

  • L-lysine is an essential amino acid. That means that the body cannot make it and must instead get it from outside sources: namely dietary intake of protein foods—although dietary supplements with L-lysine can also serve as a source. The best dietary sources of L-lysine are animal proteins, such as meats, poultry, and milk. Proteins from grains, such as wheat and corn, generally tend to be low in lysine.1 This article will address the clinical research that has been conducted on supplementation with L-lysine—with a focus on its anti-Herpes virus effects. But first, let's quickly review L-lysine's biological functions in our bodies.

    The Biological Functions Of Lysine
    L-lysine serves various important roles in human biology. One of these is its requirement for collagen synthesis.2,3 which in turn makes it important for connective tissues found in bone and skin, among other tissues. In addition, L-lysine is necessary for the synthesis of carnitine and the resultant conversion of fatty acids to energy, as well its playing roles in supporting healthy growth and development in children, and maintaining healthy immune function.4 In particular, L-lysine plays a critical role in the management of Herpes simplex virus (HSV) infections, via its antagonistic relationship with L-arginine.

    Lysine And Herpes Virus Infections
    Lysine appears to have an antagonistic relationship with the amino acid arginine, which is required for the replication of HSV. Lysine competes with arginine for absorption in the intestine, reabsorption in the renal tubules, and transport across the plasma membrane into cells. in vitro, lysine inhibits the growth-promoting action of arginine on HSV. Increasing over all lysine intake or influencing the lysine-to-arginine ratio is the basis for lysine's potential benefit in managing an HSV outbreak,5,6 as demonstrated in various studies.

    Lysine and herpes study 1
    This study7 examined the efficacy of long-term preventive effect of lysine supplementation. Twenty-six volunteers with a history of frequently recurring HSV on their lips (HSV labialis), completed a 12-month double-blind crossover study. The frequency of Herpes recurrences ranged from four to sixteen per year (with many occurring twelve times in the past year). The participants included in the statistical analysis were randomly divided into two groups at the beginning of the study. Group A, consisting of fifteen members, began with lysine tablets. Group B, comprising eleven members, started with a placebo. The experimental group received daily oral supplements of 1,000 mg L-lysine. They were instructed to take two tablets every morning before breakfast. A crossover took place at sixmonths (where the L-lysine group switched to a placebo, and vice versa). At this time, a new 6-month supply of tablets was issued, and the participants were instructed to continue the daily regimen without interruption. At the end of the second 6-month period the study was terminated. Serum samples were analyzed at scheduled intervals.

    Results showed that at the end of the first 6-month period, the frequency of lesions in those subjects given lysine did not differ significantly from the frequency in those given the placebo. Although this was surprising, it was even more surprising that the subjects who began taking lysine during the second 6-month test period reported significantly fewer lesions than those who had reverted to placebo (p < 0.05). In this group, the frequency of herpetic lesion episodes over a 6-month period was 1.18 times versus 4.05 compared to baseline. Similarly, during the second 6-month test period, when Group A was taken off the lysine supplementation, there was a significant increase in the frequency of lesions (p < 0.01). Conversely, patients in Group B, in which lysine was now added, reported a significant decrease in lesion recurrence (p < 0.01).

    In light of the significant differences found between the groups at 12 months, a further examination of the data was conducted to determine if there was any correlation between a patient's serum levels of lysine and the number of lesion recurrences. Results for this sample population indicated that when a person's serum lysine concentration exceeded 165 nmol/ml, there was also a corresponding significant decrease in recurrent lesions (p < 0.05). The results obtained herein tended to corroborate previous in vitro data indicating that lysine is a herpes virus inhibitor. If, 1,000 mg of L-lysine is taken daily over a 6-months period, and if the blood levels exceed 165 nmol/ ml, the number of lesion recurrences is significantly reduced in most cases. When lysine supplements are discontinued, lesion frequency significantly increases again if serum levels fall below 165 nmol/ml. In conclusion, prophylactic lysine may be useful in managing selected cases of recurrent HSV labialis if serum lysine levels can be maintained at adequate concentrations.

    Hence, this study explains why some reports indicate that oral L-lysine administration is effective in the treatment/ recurrence of herpes viral infections, while other reports have not found a benefit. Namely, it's not enough to consume a specific dose of lysine. Rather it is necessary that blood levels of lysine be made to exceed 165 nmol/ml in order to see clinical benefits. Consequently, for some individuals, 1,000 mg of lysine daily may provide the desired prophylactic effect, while others may require a higher dose such as 3,000 mg daily.

    Lysine and herpes study 2
    In this study, researchers also evaluated the preventive effect of L-lysine monohydrochloride 1000 mg daily on recurrent HSV labialis in 65 patients in a double-blind, placebo-controlled, crossover study.8 After 12 weeks of lysine treatment the patients shifted to placebo treatment for a similar period. On the whole, lysine had no effect on the recurrence rate of herpes simplex. However, significantly more patients were recurrence-free during lysine than during placebo treatment (p = 0.05), suggesting that certain patients may benefit from prophylactic lysine administration.

    Lysine And Herpes Study 3
    In another double-blind, placebo-controlled, multicenter trial,9 subjects were given oral L-lysine monohydrochloride—this time with 3,000 mg—for the prevention and treatment of recurrent HSV infection. The treatment group was given L-lysine monohydrochloride tablets (1,000 mg L-lysine per dose) three times a day for six months. A total of 27 (six 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 (p < 0.05) less HSV infections, symptoms were significantly (p < 0.05) diminished in severity and healing time was significantly reduced (p < 0.05). The researchers concluded that L-lysine appears to be an effective agent for reduction of occurrence, severity and healing time for recurrent HSV infection.

    Lysine and herpes study 4
    In a prospective, randomized, double-blind, placebo-controlled, cross-over study10 of forty-one patients, researchers found that oral ingestion of 1,248 mg a day of L-lysine monohydrochloride shows evidence of decreasing the recurrence rate of herpes simplex attacks in non-immunocompromised hosts. A dose of 624 mg a day was not effective. L-lysine may also be capable of decreasing the severity of symptoms associated with recurrences.

    Lysine and herpes study 5
    In a fifth clinical study,11 45 patients with frequently recurring herpes infection were given 312–1,200 mg of lysine daily in single or multiple doses. The clinical results demonstrated a beneficial effect from supplementary lysine in accelerating recovery from herpes simplex infection and suppressing recurrence. Tissue culture studies have demonstrated an enhancing effect on viral replication when the amino acid ratio of arginine to lysine favors arginine. The opposite, preponderance of lysine to arginine, suppresses viral replication and inhibits cytopathogenicity of herpes simplex virus.

    Lysine and herpes study 6
    To test the effect of lysine supplementation on herpes infection, 1543 subjects were surveyed12 by questionnaire after a sixmonth trial period. The study included subjects with cold sores, canker sores, and genital herpes. Of these, 54 percent had been diagnosed and treated by a physician. The results showed that the average dosage used was 936 mg of lysine daily. Eighty-four per cent of those surveyed said that lysine supplementation prevented recurrence or decreased the frequency of herpes infection. Whereas 79 percent described their symptoms as severe or intolerable without lysine, only 8 percent used these terms when taking lysine. Without lysine, 90 percent indicated that healing took six to 15 days, but with lysine 83 percent stated that lesions healed in five days or less. Overall, 88 percent considered supplemental lysine an effective form of treatment for herpes infection.

    L-lysine, an essential amino acid, has important roles to play in human biology. With regard to human clinical research with supplemental L-lysine, perhaps the most significant contribution that this amino acid has made is in managing HSV outbreaks. Multiple studies have indicated that L-lysine supplementation is effective in reducing the frequency of HSV outbreaks and speeding up their healing time when an outbreak does occur. For most people with the HSV, supplementation with 1,000 mg/day is recommended for preventive purposes. Once an outbreak occurs, however, intake should be increased to 3,000 mg/day.


    1. L-Lysine monograph. Altern Med Rev. 2007;12(2):169–72.
    2. Flodin NW. The metabolic roles, pharmacology, and toxicology of lysine. J Am Coll Nutr1997;16:7–12.
    3. Hall SL, Greendale GA. The relation of dietary vitamin C intake to bone mineral density: results from the PEPI study. Calcif Tissue Int 1998;63:183–9.
    4. L-lysine. Monograph. Altern Med Rev. 2007 Jun;12(2):169–2.
    5. Tankersley RW. Amino Acid Requirements of Herpes Simplex Virus in Human Cells. J Bacteriol. 1964;87(3):609–613
    6. Thein DJ, Hurt WC. Lysine as a prophylactic agent in the treatment of recurrent herpes simplex labialis. Oral Surg Oral Med Oral Pathol. 1984 Dec;58(6):659–66.
    7. Milman N, Scheibel J, Jessen O. Lysine prophylaxis in recurrent herpes simplex labialis: a double-blind, controlled crossover study. Acta Derm Venereol. 1980;60(1):85–7.
    8. Griffith RS, Walsh DE, Myrmel KH, Thompson RW, Behforooz A. Success of L-lysine therapy in frequently recurrent herpes simplex infection. Treatment and prophylaxis. Dermatologica. 1987;175(4):183–90.
    9. McCune MA, Perry HO, Muller SA, O'Fallon WM. Treatment of recurrent herpes simplex infections with Llysine monohydrochloride. Cutis.1984 Oct;34(4):366–73.
    10. Griffith RS, Norins AL, Kagan C. A multicentered study of lysine therapy in Herpes simplex infection. Dermatologica. 1978;156(5):257–67.
    11. Walsh DE, Griffith RS, Behforooz A. Subjective response to lysine in the therapy of herpes simplex. J Antimicrob Chemother. 1983 Nov;12(5):489–96.
  • The Amazon rainforest, the largest rainforest on earth, has been targeted by pharmaceutical companies for over a century as a rich source of new plant-derived drugs. The Amazon rain forest is even more so a treasure trove of botanicals for the dietary supplement industry. This rain forest stretches over a billion acres in Brazil, Venezuela, Columbia, and the eastern Andean area of Ecuador and Peru. It is home to hundreds of thousands of plants, many of which are used as folk medicines.

    Among the many beneficial traditional Amazon botanicals which have emerged in recent years, Uña de gato, or Cat's Claw (Uncaria tomentosa), is one of the most beneficial of all. A woody vine, the plant earns its name due to its sharp, claw-like thorns. Dispersed throughout Central and South America, cat's claw has been used for centuries by native tribes. The entire Uncaria genus, of which there are 60 or so known species, occurs in the tropics. These are coarse shrubs which climb by means of sharp spines or thorns. One species, Uncaria guianensis, is also called cat's claw. But this species lacks the same broad use and science as Uncaria tomentosa.

    Good Ghost, Bad Ghost
    One of the tribes most associated with cat's claw is the Ashaninka. Their tribal name means "belonging to the Inca." Formerly fierce warriors, the Ashaninka served as the last line of stubborn and dangerous defense against the Spanish conquest of Peru and the eventual destruction of the Incan empire. Many Ashaninka people live in the Chanchamayo region of the Peruvian Amazon, an area of hilly and mountainous rain forest. According to the Ashaninka healers, there are two types of cat's claw, good ghost plants and bad ghost plants. The Ashaninka call the good ghost cat's claw Saventaro, meaning powerful plant. You have to be an expert to know the difference. Fast-forwarding to the scientific present, scientists now have identified two distinct chemotypes of cat's claw. The good ghost cat's claw plants contain POA's or pentacyclic oxindole alkaloids. These compounds provide significant benefits to health. But the so-called bad ghost plants contain TOA's, tetracyclic oxindole alkaloids, which actually counteract the beneficial effects of the plant. The Ashaninka explanation of which plants to use and which to avoid are affirmed and explainable by modern scientific analysis. The bridge between traditional knowledge and scientific rigor is being established with thousands of medicinal plants worldwide. Among medicinal plants from Amazonia, Saventaro is a science heavyweight.

    Powerful Plant
    On a hot, sunny day, I stood overlooking a long green river valley outside of La Merced Peru with Johannes Keplinger, a bright and talented Austrian familiar with that region, the Ashaninka people, and Saventaro cat's claw. His father, Klaus Keplinger, is a pioneer in the study and promotion of cat's claw, or Saventaro. Klaus Keplinger is a true friend of the Ashaninka people, and has worked hard for decades on their behalf. Elder Keplinger's dedication to the cat's claw cause traces back to an influential meeting with a shaman in 1959, when he took part in a mountaineering expedition in Peru. The Ashaninka shaman told Keplinger about a healing plant. That plant was Saventaro, the POA chemotype, or good ghost cat's claw. In the early 1970's Keplinger was told about a successful cancer treatment of a friend, using cat's claw. Keplinger returned to the Chanchamayo region in 1975, and has worked with the Ashaninka people in the sustainable harvesting and initial processing of the POA chemotype of cat's claw, Saventaro, for eventual manufacture into a standardized extract. Keplinger's son Johannes now is responsible for the project, which operates in Austria under the name Immodal Pharmaka.

    Joining Johannes and me were photographer Donna Horn and an Ashaninka Indian named Josias Macuyama. We were together to visit every aspect of the world of Saventaro cat's claw, from the forest to drying harvested material. Donna shot photographs throughout the entire trip, while Josias works directly with the Keplinger family in the Saventaro cat's claw project. Josias is an influential and respected man in the Ashaninka world. As one of the tribe, he knows the challenges his people face. At the same time, Josias enjoys a European education, and a broader world perspective. The four of us made a friendly and cooperative quartet as we travelled throughout the Chanchamyo region of the Peruvian Amazon, meeting with a broad range of people involved with Saventaro cat's claw.

    We hiked into the hot rainforest to see cat's claw plants with a couple of native Ashaninka harvesters named Mario and Nestor, and a local medicine man Manuel Harena. There we witnessed first hand how Ashaninka people harvest Saventaro cat's claw in three ways that set them apart from others. First the harvesters visually determining whether a plant is the right chemotype. Secondly, they harvest root material instead of bark, which is more common. Additionally, they maintain a sustainable harvesting project in thousands of acres of rain forest, protecting the natural habitat and preventing depletion of cat's claw supplies. The Ashaninka use GPS units to identify exact locations of cat's claw plants, which can be huge, twining through an acre or more of forest, winding around trees, taking over a lot of ground. Each plant is tagged with an identification code. Up to one third of the lateral roots of a plant is harvested, and then that plant is left alone for ten years before any further harvesting takes place. This enables new lateral roots to grow, and contrasts sharply with harvesting of cat's claw in many other regions, where plants are cut down and ripped up, dried and ground, decimating forest and depleting supplies of this potent rain forest medicine.

    Compounds in Cat's Claw
    The phytochemistry of cat's claw, Uncaria tomentosa has been very well studied. Uncaria tomentosa contains numerous phytochemicals that account for the plant's traditional and current uses. The highly studied oxindole alkaloids, notably the POA's, demonstrate immune-modulating and antileukemic activity. Other constituents called quinovic acid glycosides show anti-inflammatory and antiviral activity. Antioxidant phenols and plant sterols contribute to the plant's anti-inflammatory properties. Yet another group of cat's claw compounds called carboxyl alkyl esters demonstrate immune-enhancing, anticancer, and anti-inflammatory activity, as well as cell-repairing properties.

    In his Amazonian Ethnobotanical Dictionary, botanist Dr. James A. Duke describes the use of cat's claw in Peru for anti-inflammatory, and cytostatic (retards tumor cells) purposes. In popular literature, cat's claw is increasingly promoted for its well established immune enhancing properties. Studies support the traditional use of cat's claw for anti-inflammatory and immune-enhancing purposes. By helping to prevent and repair damage to DNA, cat's claw may possibly prove to be a bonafide life extender.

    Cat's Claw Benefits
    Studies conducted with the POA chemotype of cat's claw show that these agents possess anti-inflammatory, antimutagenic, antiviral and immune-stimulating properties. The POA alkaloids in the vine demonstrate immune-enhancing activity by producing an increase in phagocytosis, a process by which potentially harmful materials are "eaten" by protective cells. In studies of quinovic acid glycosides in the plant, researchers observed significant anti-inflammatory activity. Additionally, these same compounds were shown to inhibit several types of common viruses. In studying triterpenoid saponins, scientists observed that these chemical agents inhibited the growth of some tumor cells. In Austria, Saventaro cat's claw extract is prescribed by physicians under the name Krallendorn for the treatment of rheumatoid arthritis. In many cases, it enables sufferers of this disease to gradually ease off of medication and live normal lives. The extract demonstrates benefit as an adjunct to chemotherapy and radiotherapy in cancer treatment, and improves overall parameters of health in cases of various cancers. Saventaro cat's claw also helps to treat viral infections including Herpes simplex and Varicella zoster, and improves immune function and several parameters of life quality in cases of HIV and Aids. This phytochemical-packed Amazonian plant has become a highly studied and effective medicine.

    Cat's Claw and Sustainability
    One challenge we face in the era of modern plant medicine is how to engage in herbal work in a manner that sustains plants, people and the natural environment. In addition to harvesting Saventaro cat's claw root in an eco-friendly way, the collaboration between Immodal and the Ashaninka people provides other benefits. Harvesters of Saventaro cat's claw root are paid a fair daily wage that exceeds local wages. They are additionally paid per kilo of lateral roots harvested. After that, additional funds accrue to the Ashaninka villages for medicine and education. This type of green business bodes well for the future.

    Some people state that the Amazon rain forest should be better protected, because someday we may find an extraordinary rainforest remedy that is a true lifesaver, one that treats serious diseases and provides extraordinary health benefits. We don't need to wait for some future discovery to start taking better care of one of the greatest geographic resources on earth. The traditional native medicine cat's claw is that extraordinary rainforest remedy. The POA chemotype of cat's claw, called Saventaro by the Ashaninka Indians, demonstrates profound medicinal value. Its immune-modulating, antiviral, antitumor and anti-inflammatory effects make Saventaro a medicine deserving of greater recognition and more widespread use.