Lysine as a therapeutic supplement
Lysine is an essential amino acid that plays a crucial role in protein synthesis and muscle maintenance. It is commonly sourced from dietary proteins such as meat, dairy, and legumes, with a recommended daily intake of about one gram. Lysine supplements are often proposed for various therapeutic uses, most notably in the prevention of herpes simplex virus infections, including cold sores and genital herpes. Some studies indicate that regular lysine supplementation might reduce the frequency and severity of herpes flare-ups, although results are mixed and more extensive research is needed to confirm these benefits. Additionally, lysine has been explored for potential effects on anxiety, calcium absorption, and wound healing, but scientific support for these uses remains limited. While generally considered safe, concentrated lysine supplements may pose risks, particularly at high doses, which have been linked to issues such as gallstones. Therefore, individuals should approach lysine supplementation with caution and consult healthcare professionals, especially if they have existing health conditions or are pregnant.
Lysine as a therapeutic supplement
DEFINITION: Natural substance of the human body used as a supplement to treat specific health conditions.
PRINCIPAL PROPOSED USE: Herpes simplex prevention (cold sores, genital herpes)
OTHER PROPOSED USES: Anxiety, stress, schizophrenia, calcium absorption, healing injuries
Overview
Lysine is an essential amino acid obtained from food or supplements that the body uses to make proteins and maintain muscles. Some evidence suggests that supplemental lysine may help prevent herpes simplex virus infections such as cold sores and genital herpes, but the evidence is mixed.
Requirements and Sources
Most people need about one gram of lysine per day. The requirement may be greater for athletes and people recovering from major injuries, especially burns. The body requires 35 milligrams of lysine per kilogram of body weight, but in general, if a person is ingesting enough protein, they are likely ingesting enough lysine. The richest sources of lysine are animal proteins such as meat and poultry, but it is also found in dairy products, eggs, legumes, spirulina, soybeans, and fenugreek seeds.
Therapeutic Dosages
A typical therapeutic dosage of lysine for herpes infections is one gram three times daily. It is usually sold as L-lysine in a capsule, cream, or liquid. Lysine can be taken as a regular part of the diet to prevent herpes flare-ups or, perhaps, at the first sign of an attack. Although the evidence is not strong, there may be some advantages to restricting the intake of foods that contain a lot of arginine, such as chocolate, peanuts, other nuts and seeds, and, to a lesser extent, wheat.
The maximum daily intake of lysine is 7.5 grams per day, though most professionals recommend taking less than 6 milligrams in twenty hours.
Therapeutic Uses
Some small studies suggest that regular use of lysine supplements can help prevent flare-ups of cold sores and genital herpes, although other studies have not found any benefit. Lysine has also been proposed as a treatment to take at the onset of a flare-up, but at least one study failed to find it effective for this purpose.
Both cold sores and genital herpes are caused by a virus called herpes simplex. After a person is infected, this virus hides in certain nerve cells and reemerges during times of stress. Test-tube research suggests that lysine fights this virus by blocking arginine, an amino acid the virus needs to replicate. For this reason, lysine might be most effective when used in conjunction with a low-arginine diet. However, this widely stated claim has not been proven. (Note that if this were true, people who have herpes would need to avoid taking arginine supplements.)
Scientific Evidence
It appears that regular use of lysine supplements, when taken in sufficient doses, might reduce the number and intensity of herpes flare-ups. One double-blind, placebo-controlled study followed fifty-two participants with a history of herpes flare-ups. While receiving three grams of L-lysine every day for six months, the treatment group experienced an average of 2.4 fewer herpes flare-ups than the placebo group, a significant difference. The lysine group’s flare-ups were also significantly less severe and healed faster.
Another double-blind, placebo-controlled crossover study on forty-one subjects also found improvements in the frequency of attacks. This study found that 1,250 milligrams (mg) of lysine daily worked, but 624 mg did not. Other studies, including one that followed sixty-five individuals, found no benefit, but they used lower dosages of lysine. Many people take lysine at the onset of a herpes attack. However, a double-blind, placebo-controlled study evaluating this method found no benefit. One should consider using the herb lemon balm instead.
Although some of these studies are promising, none were large enough to provide conclusive answers. More evidence is needed to determine whether lysine is effective for preventing herpes simplex.
Many other uses for lysine exist, though most are not scientifically supported. Studies in humans have suggested lysine may be effective in reducing anxiety and stress. Studies have also shown promise for lysine's ability to improve calcium absorption and retention, which could prevent or treat osteoporosis or osteopenia. However, studies investigating this use have been small and poorly constructed. Animal studies have suggested that 15 percent lysine cream may be beneficial in slow-healing wounds. Other studies investigated the use of lysine tablets for blood sugar and blood pressure control, as well as high-dose lysine for schizophrenia symptoms. The research findings in each investigation were mixed, and more human clinical studies are necessary before making health claims.
Safety Issues
Although lysine is an essential part of the diet, the safety of concentrated lysine supplements has not been well studied. In animal studies, high dosages have caused gallstones and elevated cholesterol levels, so individuals with these problems should use caution when using lysine. Lysine can interfere with aminoglycoside antibiotics like gentamicin, neomycin, and streptomycin.
Maximum safe dosages for young children, pregnant or nursing women, and those with severe liver or kidney disease have not been established. In persons taking lysine to treat herpes, arginine might counteract the potential benefit.
Bibliography
Chang, Jane Y., et al. “A Narrative Review of Alternative Symptomatic Treatments for Herpes Simplex Virus.” Viruses, vol. 15, no. 6, June 2023, p. 1314, doi:10.3390/v15061314.
Flodin, N. W. “The Metabolic Roles, Pharmacology, and Toxicology of Lysine.” Journal of the American College of Nutrition, vol. 16, 1997, pp. 7-21.
Lubeck, Brittany. “Lysine: Benefits, Side Effects, Dosage, and Interactions.” Verywell Health, 14 Sept. 2024, www.verywellhealth.com/can-lysine-help-to-heal-cold-sores-88922. Accessed 20 Sept. 2024.
“Lysine Information.” Mount Sinai, www.mountsinai.org/health-library/supplement/lysine. Accessed 20 Sept. 2024.
Richter, Amy. “4 Impressive Health Benefits of Lysine.” Healthline, 2 Apr. 2024, www.healthline.com/nutrition/lysine-benefits#Other-potential-benefits. Accessed 20 Sept. 2024.