Top 6 Health Benefits of Lysine, Backed by Science

Jillian Kubala, MS, is a registered dietitian based in Westhampton, NY. Jillian uses a unique and personalized approach to help her clients achieve optimal wellness through nutrition and lifestyle changes. In addition to her private practice, Jillian works as a writer and editor and has written hundreds of articles on nutrition and wellness for top digital health publishers.

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Lysine offers benefits, such as preventing herpes flares, reducing anxiety, and improving muscle strength. Lysine is an essential amino acid, or molecules that act as the building block of proteins.

Your body cannot make essential amino acids like lysine on its own, so you must get it through your diet. You can also take lysine as a supplement, often labeled "l-lysine."

Lysine may benefit people who have recurrent infections caused by the herpes simplex virus (HSV). HSV needs the amino acid arginine to replicate. Lysine blocks HSV from using arginine, which prevents the virus from reproducing.

One review found that taking more than 3 grams of supplemental lysine may reduce the recurrence of HSV lesions like cold sores and genital sores. The research is limited and based on small sample sizes and short study durations.

More research is needed to understand how lysine affects people with herpes and what minimum dosage is needed to treat the infection.

Taking 500 milligrams of supplemental lysine twice daily for 16 weeks has been shown to reduce systolic blood pressure in people with hypertension (high blood pressure) and suboptimal lysine intake.

Systolic blood pressure is the top number of a blood pressure reading and measures the pressure in your arteries when your heart beats. High blood pressure can increase your risk of heart disease and stroke. More research is needed to understand the effects of lysine on high blood pressure.

Lysine may improve anxiety and stress when you combine it with arginine, but more studies are needed.

Your body requires amino acids to produce neurotransmitters. These chemical messengers help nerve cells communicate. Low amino acid intake can lead to an imbalance in neurotransmitters, which causes anxiety and stress.

Lysine supplements have also been shown to lower inflammation and increase antioxidants in the brain, but more studies are needed. Both might improve symptoms of schizophrenia, which affects behavior and thinking.

Lysine may protect against osteoporosis, which is characterized by brittle, weak bones. Lysine increases the absorption of calcium, an essential mineral for bone health.

Some preliminary evidence suggests that lysine, alongside arginine, can promote bone cell activity and increase collagen production. One review of largely animal and lab studies found that essential amino acids, such as lysine, may positively affect bone health in older adults.

The exact dosage necessary to support bone health is unclear. More human studies are needed before lysine supplements can be recommended to support bone health.

Lysine-rich diets may protect against protein breakdown and improve muscle strength. You can use lysine as a protein supplement to repair muscle tissue after physical activity.

Lysine plays an important role in the production of collagen, a protein that helps build connective tissue in your body. It is especially essential for the production of a key part of collagen called hydroxylysine.

Lysine supplements are thought to help with wound healing. They may help heal mucosal wounds, which affect the moist inner lining of your mouth. This could help decrease or prevent mouth sores and inflammation from radiation or chemotherapy.

More research is needed to understand how lysine supplements impact collagen production and wound healing in humans.

Lysine is concentrated in a number of plant- and animal-based foods, such as:

Most people get enough lysine through their diet. Taking lysine supplements could be helpful for people who do not eat a lot of lysine-rich foods or are trying to manage a condition like herpes.

Lysine supplements are most commonly available as capsules and powders. You can take lysine on its own or alongside other amino acids, such as arginine.

Lysine is safe in doses of up to 3,000 milligrams a day for up to one year and up to 6,000 milligrams a day for up to eight weeks.

Higher doses may be safe, but they can cause side effects. Some people might require higher or lower doses of lysine than others. Reach out to a healthcare provider if you have questions about lysine dosage.

Lysine supplements are considered relatively safe. People with underlying conditions and those who are pregnant or breastfeeding should avoid lysine supplements unless a healthcare provider prescribes them.

Lysine supplements are also unsafe for people with lysinuric protein intolerance. This rare genetic condition causes an inability to digest and use amino acids like lysine. Taking lysine supplements may cause abdominal cramps and diarrhea.

When buying a supplement, make sure the product is independently tested. Unlike medications, supplements are not regulated by the FDA. This means their quality and safety can vary. Independent testing confirms that the supplement contains the ingredients listed on the label and is free from harmful contaminants. Check for seals from reputable organizations such as NSF International, USP (United States Pharmacopeia), or ConsumerLab.

Lysine is not known to interact with any medications. Do not start taking lysine supplements without clearing it with a healthcare provider if you are taking one or more medications.

Consider supplement form, cost, and additives. A powdered lysine supplement might be a better choice if you cannot tolerate swallowing pills.

Look for ingredients that you may prefer to avoid, such as added sugars, fillers, and artificial colors and flavors.

Lysine is considered safe at higher doses, but do not take more than 6,000 milligrams per day. Doses higher than this may cause abdominal cramps, diarrhea, and nausea.

Lysine has not been shown to cause side effects in moderate doses. Stop taking the supplement if you have side effects after taking a lysine supplement. Contact a healthcare provider right away for advice.

Lysine supplements may have benefits for people with a low dietary intake of this amino acid, recurrent herpes outbreaks, or anxiety.

It is an essential amino acid involved in growth, tissue repair, collagen production, and other important bodily functions. Lysine is found in meat, fish, eggs, and beans and can also be taken as a dietary supplement.

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