Lysine Benefits for the Gut, Brain, Diabetes & Even Cold Sores

September 6, 2024

Did you know that a building block of protein can help improve a range of conditions from cold cores to cancer? It may seem like a myth, but it’s just science behind the many lysine (or L-lysine) benefits.

For years, people have been using L-lysine to treat the herpes virus and recover from workouts. As it turns out, this amino acid is good for more than just these two things.

Lysine benefits are extensive and include everything from helping manage anxiety to diabetes. This amino acid is found in food as well as available in supplement form.

What Is Lysine?

Lysine is an essential amino acid. Many people know that several amino acids are known as the “building blocks of protein” and are needed in order for a huge number of internal functions to work properly, including growth.

L-lysine was first discovered by a German scientist known only as Dreschel in 1889, who was able to isolate the amino acid from casein, or milk protein. The exact structure of the molecule was recorded just three years later.

Of the few hundred amino acids found in nature, 20 are necessary for protein creation and growth, and only 10 of those 20 can be produced by the body. The remaining 10 are known as “essential” amino acids because humans must consume them for proper health.

Amino acid deficiencies cause a degradation of internal cells and can lead to huge problems, so it’s important to get enough of them in your diet. It’s common to be deficient in lysine and glutamine, in particular.

Essential amino acids are most often stereoisomers, meaning they exist in two variations that are identical to one another as mirror images. There are both D- and L- forms of these amino acids, and the L- form is used in protein synthesis and therefore the form found in food and supplements.

Because of this, most people simply refer to this nutrient as “lysine” for short.

There are many incredible L-lysine benefits, from its use as a common treatment for cold sores to a potential anti-anxiety supplement.

As is true with most nutrients available in supplement form, it can be taken orally but is absorbed best into the body when consumed through dietary sources. It’s found in large amounts in various kinds of meat, beans, cheeses and eggs.

Specifically, L-lysine is very important in the creation of carnitine, which converts fatty acids into energy and also lowers cholesterol levels. It also seems to play a role in absorbing calcium and helps the body form collagen, which aids in the growth and maintenance of bones and connective tissue (including skin).

Benefits

As a natural disease-fighting agent, lysine benefits the human body in a variety of ways, many of which are only recently undergoing research. Here are some of the top L-lysine benefits:

1. May support a healthy gut

An extremely common problem that millions of people have, many of whom aren’t even aware of it, is leaky gut syndrome. This condition is the permeating of your digestive tract lining, allowing larger-than-intended particles to get out of your digestive system and into the rest of your body.

This causes allergic reactions, low energy, joint pain, autoimmune diseases and thyroid disease.

A form of L-lysine known as poly-L-lysine was found to have anti-inflammatory effects on the lining of your gut, hopefully leading to more extensive research on how this amino acid may help improve the health of this lining and possibly prevent leaky gut.

It was found to help support the functional status of the gut in turkeys even better than arginine, another amino acid.

Although not necessarily directly linked to leaky gut syndrome, L-lysine has also been found in mice to suppress pancreatitis, an inflammation of the pancreas, another important part of the digestive system.

2. Reduces diabetes-related problems

One of the most difficult things patients with diabetes experience is an increased risk for infection and other diabetes-related conditions. In the past several years, much attention has been given in this context to the large presence of advanced glycation end products, referred to as AGEs for short.

These AGEs are part of the aging process in the body in all people, but they’re in very high concentrations in diabetic patients. They’re implicated in many health conditions linked to diabetes, leading scientists to study therapies that involve stopping AGEs from collecting in large numbers.

Studies suggest that one of the L-lysine benefits for diabetics may be to prohibit the formation of AGEs in those with diabetes by preventing specific paths of glycation that lead to these products, helping stave off infection.

Furthermore, a randomized, controlled trial published in the Journal of Nutrition found that administering lysine to healthy adults led to lower circulating glucose and insulin responses. Plus, another randomized, double-blind, placebo-controlled clinical trial involving 110 with prediabetes found that Lysulin — a nutraceutical that contains lysine, vitamin C and zinc — not only improved glycemic control and reduced the progression of diabetes compared to the control group, but it also helped reduce total and LDL cholesterol levels.

Thus, the addition of L-lysine benefits those following a diabetic diet plan if lysine foods are included.

3. Increases absorption of calcium

Consuming L-lysine is associated with better absorption of calcium, which leads some to believe that it can help people with or at risk for osteoporosis.

Because of the important role calcium plays in bone health, logic suggests it may be a beneficial nutrient to supplement those with brittle bones, and research conducted on twins even shows that higher amino acid intake — namely alanine, arginine, glutamic acid, leucine, lysine and proline — is beneficial for bone health.

Calcium is good for more than just your bones, too. Consuming appropriate amounts of calcium is associated with:

healthy weight
cancer prevention
PMS symptom reduction
dental health
nerve and muscle health
the prevention of diabetes

Athletes often take L-lysine as a protein supplement to improve performance. This, too, may be related to the way L-lysine causes your body to absorb calcium.

4. May decrease outbreak and frequency of cold sores

If you’ve heard of L-lysine before, it’s probably in conjunction with a natural cold sore remedy. Cold sores are a result of the herpes simplex-1 virus, also referred to as HSV-1.

While research is inconsistent on the subject, most individuals who use L-lysine to treat cold sores find it to be very effective. Some studies support that L-lysine can help reduce the number of HSV outbreaks someone has, while others say that outbreaks happen at the same frequency but last a shorter period of time.

Experts generally agree that L-lysine is unlikely to completely stop outbreaks altogether but may aid in lessening their severity and/or frequency.

One study using a cream combining L-lysine with herbs and zinc found that 87 percent of patients saw their cold sores go away by day six of treatment. This is significant because these outbreaks usually last about 21 days.

The way this nutrient may fight cold sores is not entirely clear, but one such reason may be the way that it interacts with arginine, another amino acid that’s produced in small amounts within the body. Arginine has been shown to increase the replication rate of herpes virus cells, and high amounts of L-lysine in the body decrease the activity of arginine because they work against one another.

5. Reduces anxiety and other psychological symptoms

Along with eating foods high in B vitamins, magnesium and omega-3 fatty acids, you can also try increasing your L-lysine intake to minimize anxiety. Because L-lysine may help your body absorb calcium, which is another beneficial nutrient for anxiety sufferers, this may be one of the primary ways in which it helps remedy anxiety.

In addition to helping you absorb calcium more efficiently, L-lysine behaves like a serotonin receptor antagonist. That’s a wordy phrase that means it partially binds to serotonin receptors in order to partially prevent anxiety responses.

Research on rats indicates that L-lysine helps reduce stress-induced anxiety responses, including diarrhea.

This is especially important in developing countries in which wheat is the primary staple food. People living in these environments are much more likely than those in first-world countries to be deficient in L-lysine.

Research suggests that fortifying diets of people in wheat-dependent countries can help reduce both stress-induced anxiety and diarrheal responses.

It’s possible that L-lysine benefits those with schizophrenia as well, which manifests in extremely serious symptoms often linked to anxiety. Preliminary findings show that L-lysine supplementation along with conventional therapy can help decrease negative and general symptoms of schizophrenia, although dosing and long-term effects have not yet been determined.

6. May help in the treatment of cancer

Researchers continue to discover more ways that nutrients found in our food and in nature may potentially target malignant cells without killing good ones.

In 2007, scientists at Florida State University studied the effects of “lysine conjugates” on damaged strands of DNA, like the ones found in cancer. Basically, this substance can locate a damaged strand by identifying “cleavage” in it (a damaged spot) and cause the rest of the strand to cleave (tear apart) as well.

The cell is usually unable to repair this damage, leading to apoptosis, the death of cells.

The more you learn about lysine, the more you realize how fascinating the potential of this treatment is and how it works alongside specific types of light. The cancer-killing ability of lysine conjugates are only activated when exposed to particular types of light, which allows researchers, and potentially doctors, to inject or place the treatment into the most concentrated location of cancer cells and activate them at their most potentially effective spots.

The scientists conducting the FSU study found results ranging from 25 percent all the way to 90 percent of destroyed cancer cells, which is astounding.

A lysine oxidase was tested against instances of colorectal cancer in mice in 2014. In this study, the injection of lysine oxidase was associated with zero deaths and shrunk solid tumors in significant amounts, signifying this may be a promising form of cancer treatment for colorectal cancer in the future.

Cancers associated with the bone marrow, such as leukemia, may also meet their match with L-lysine, according to preliminary research. In one study on rats, researchers suggest that L-lysine injection helped prevent genotoxicity (DNA and RNA damage) in cells exposed to a cancer-causing substance.

7. Promotes wound healing by helping create collagen

L-lysine is an essential amino acid that plays a crucial role in collagen formation, which is vital for skin structure and wound healing. It also helps the body absorb calcium, which is important for collagen production and bone health.

This amino acid is required for the cross-linking of collagen fibers, which is essential for wound repair and tissue strength. A 2013 study found that increasing lysine acetylation accelerated wound healing by enhancing fibroblast migration and collagen deposition.

Other studies show that L-lysine supplementation accelerates wound healing by supporting collagen synthesis as well. In one study, patients with chronic wounds experienced faster recovery when treated with lysine-enhanced dressings.

8. May help treat dry eyes

This essential amino acid has been explored for its potential role in reducing symptoms of dry eyes by enhancing the integrity of ocular tissues. Some studies suggest that it helps maintain tear film and reduces inflammation associated with dry eyes.

A 2022 study found that lysine supplementation could potentially benefit dry eye conditions, and a 2021 study published in Frontiers in Pharmacology found that patients who had excimer laser refractive surgery with photorefractive keratectomy had significantly improved “corneal nerve restoration” when taking an amino acid supplement that included lysine.

9. Could reduce high blood pressure

There is evidence that L-lysine may help reduce high blood pressure by modulating nitric oxide production, which relaxes blood vessels. One study in patients with hypertension found that supplementing with the amino acid reduced blood pressure levels, particularly in people with insufficient lysine intake in their diets.

10. Enhances muscle strength

L-lysine is important for muscle protein synthesis, which is key to building and maintaining muscle mass. This amino acid helps the body absorb and retain nitrogen, supporting muscle growth and repair.

It appears to have potential benefits for muscle strength, particularly in older adults. A study showed that lysine supplementation may help with muscle loss and enhance strength in older women.

Additionally, lysine is often used as a protein supplement by athletes to help muscles recover from stress and potentially boost athletic performance. In fact, research reveals L-lysine supplementation has been shown to improve muscle strength and recovery times after intense physical exercise.

Top Lysine Foods

The best way to increase your lysine content is by eating foods naturally rich in the amino acid.

When eating lysine-rich foods, remember that conventional preparation methods can decrease the nutritive value of the amino acid. These include methods like reducing with a sugar-based substance, heating lysine sources in the presence of yeast or sucrose, and cooking with the absence of moisture.

The top foods high in lysine include

Lean beef and lamb
Parmesan cheese and cottage cheese
Turkey and chicken
Pork
Roasted soybeans
Tuna, salmon, sardines and cod
Shrimp, muscles, prawns and oysters
Pumpkin seeds
Eggs
White beans
Milk and yogurt
Kidney beans and other beans
Chickpeas
Pistachios, cashews and other nuts
Lentils and other legumes
Wheat germ
Brewer’s yeast
Spirulina
Fenugreek seeds
Peas

Supplements and Dosage

Getting your nutrients from foods rather than supplements is ideal whenever possible. This way, your body absorbs more of the nutrients, and you don’t risk overdosing.

However, a supplement product can be extremely beneficial in cases where you know you aren’t able to meet your daily value recommendations of specific nutrients.

The average person (around 150 pounds) should get between 800–3,000 milligrams of L-lysine in his or her diet each day.

Dosage recommendations for treating herpes outbreaks are suggested at one to three grams daily of an additional L-lysine supplement. Lysine is also available in cream form, often used to apply to cold sores for its healing effect.

Risks and Side Effects

L-lysine supplements have been known to cause some minor side effects, although consuming natural sources of lysine is not proven to have the same effect. These side effects include stomach pain and diarrhea.

There has also been one report of kidney disease linked with lysine supplements, so patients with kidney and liver impairment should use caution and consult with their health care providers before beginning to take a lysine product.

Because its effects on pregnant mothers has not been researched at length, those who are pregnant and/or nursing should avoid taking L-lysine supplements.

While L-lysine benefits those with a large number of diseases, there is evidence that it can increase the viral load of HIV patients. For this reason, those diagnosed with HIV/AIDS should not take L-lysine supplements and consume high-lysine foods only (which probably do not produce the same results).

On the positive side, scientists discovering this phenomenon are now able to use this to speed up testing of HIV-fighting treatments.

Final Thoughts

L-lysine is the L- form of lysine, which is the form absorbed by the body to build proteins. This essential amino acid cannot be produced by the human body and must be consumed with regular diet and/or supplement form. It’s also found in topical cream products.
The most commonly practiced use of L-lysine is in the treatment of the herpes simplex virus, but it has various mechanisms and variations through which it may be able to fight cancer, reducing tumor size and causing cell death in cancer cells without damaging nearby healthy cells.
Eating foods high in lysine is the most effective way to absorb this nutrient, increase amino acid levels and obtain those L-lysine benefits.
The average person needs between 800 and 3,000 milligrams of this amino acid each day.