Lysine is an essential amino acid. Reported lysine benefits include improved blood sugar control, management of anxiety and stress, collagen formation, and wound healing. Your body cannot make lysine, so you must get it from food or supplements.
There are two chemical versions of lysine: L-lysine and D-lysine. L-lysine is the bioactive form found in foods and supplements that your body uses. Lysine is an amino acid that is found mostly in animal products.
Though more research is needed, it may help reduce anxiety, prevent cold sores, improve calcium absorption, and promote wound healing. Lysine is a building block for protein. It’s an essential amino acid because your body cannot make it, so you need to obtain it from food.
It’s important for normal growth and muscle turnover and used to form carnitine, a substance found in most cells of your body. What’s more, lysine helps transport fats across your cells to be burned for energy. L-lysine is the form of lysine your body can utilize. It’s naturally found in food and is the type used in supplements.
Lysine Benefits
Because lysine is an amino acid, your body uses it to make proteins and repair muscles.
Lysine supplements may provide benefits for the following:
- Cold sores from herpes simplex virus (HSV)
- Anxiety and stress
- Blood sugar control
- Osteoporosis
- Schizophrenia
The research on many of these benefits is limited. Talk with a healthcare provider before starting lysine supplements to ensure they are safe for you.
Cold Sores
Cold sores are an unpleasant side effect of HSV. A 2017 review found that oral lysine supplementation of 3 grams (g) per day or more improved the experiences of some people with cold sores.
However, the review stated that more research is needed to determine whether lysine is an effective treatment for this condition. An earlier review conducted in 2015 also did not find enough evidence to back up claims that lysine can provide cold sore relief.
Stress and Anxiety
Studies have looked at whether lysine can help manage anxiety and stress. Research is limited, and it should be noted that many of the studies are small and don’t include many participants.
A randomized, double-blind study found that cortisol (a hormone that increased during stress), was lowered in people who consumed lysine-fortified foods for three months. The study also found that these foods reduced anxiety measures in males.
Schizophrenia
Lysine may also be used as a complementary treatment for schizophrenia, according to limited research. A small pilot study reported that people taking 6 g of lysine daily for four weeks had improved symptoms, including reduced psychosis severity.
However, the researchers reported that possible placebo effects could have impacted the self-reported findings. A randomized, controlled trial looked at the use of 6 g of L-lysine with risperidone (a drug used to treat mental conditions), in people with schizophrenia over eight weeks.
The study showed that schizophrenia symptoms decreased more for people who took L-lysine. However, the safety and efficacy of higher doses and longer-term use of L-lysine are still uncertain.
Blood Sugar Control
Lysine supplements may be useful for lowering blood sugar. A very small study found that high doses of lysine (11 g) taken with glucose resulted in small decreases in blood sugar.
Researchers think that lysine supplementation may either help with insulin secretion or help remove glucose from the blood on its own. However, more research is needed. Follow your healthcare provider’s guidance for blood sugar control.
Treating Diabetes
The results of a small study on 12 healthy volunteers suggest that lysine can slow the rise in blood glucose levels after eating. This discovery could lead to effective treatments for people with diabetes, but there is still a need for more research.
Osteoporosis
Lysine supplements may help the body absorb calcium, which can be beneficial for osteoporosis (a disease that causes weak, brittle bones). However, many studies have been done in vitro (in a lab or test tube) or on animals. This means that it’s difficult to definitively conclude the effect of lysine on treating osteoporosis in humans.
An older review on two small human trials concluded that lysine supplementation helped people absorb more calcium, a mineral vital to bone health. However, no recent trials examine lysine’s effects in humans with osteoporosis.
One study on rats concluded that dietary lysine increased the amount of calcium absorbed by the body. The study also reported that lysine supplementation prevented the rats from experiencing loss of bone matter, as seen in osteoporosis.
It’s important to note that this study was conducted in rats and did not involve human participants. We cannot say that these effects will even happen in humans.
More high-quality studies using lysine need to be done with humans before further conclusions are made. If you have osteoporosis, follow your doctor’s prescribed treatment plan. Consult your healthcare provider before taking any supplements.
Treating Herpes
Lysine might help control the herpes virus. As a result, lysine supplements may reduce the number and frequency of cold sore outbreaks, for which the herpes simplex type 1 virus is responsible.
Lysine can also help with the treatment of genital herpes. Some sources recommend that people with a history of herpes infections take 1,000 to 3,000 milligrams (mg) of lysine supplements a day.
Other Potential Benefits
Lysine — like all amino acids — is used as a building block for protein in your body. These proteins help produce hormones, immune cells, and enzymes. Lysine may have several benefits in addition to those discussed earlier.
Here are other areas where lysine may benefit your health:
- Cancer: One animal study found that lysine in combination with the antioxidant catechin reduced cancer cell growth in mice.
- Eye health: An older study in rats with diabetes found that lysine supplements could prevent the development of cataracts.
- Diabetes: One 2009 study showed that lysine may help reduce blood sugar response in people with diabetes. However, the connection is still unclear.
- Blood pressure: A study in 50 adults with lysine deficiency and high blood pressure found that lysine supplements significantly reduced blood pressure.
Adequate lysine is essential for maintaining normal health and supplements may benefit certain people and conditions.
Side Effects
While lysine supplements are generally considered safe for most people, side effects are possible.
Common Side Effects
Common side effects of lysine supplements include:
- Stomach pain
- Diarrhea
- Nausea
Typically, these gastrointestinal side effects don’t last for long and can be treated at home. They usually only occur with larger doses of lysine. However, if you experience long-term side effects from taking oral lysine, visit your healthcare provider.
Severe Side Effects
Severe side effects are rare but possible, like kidney failure. Kidney failure has been reported from taking too much lysine. One case report on a 44-year-old woman found that high doses of lysine caused Fanconi Syndrome, a severe disorder involving the kidneys. Her symptoms eventually led to kidney failure.
As this case report was done on just one person, the evidence of kidney failure associated with taking lysine is limited. Additional research available on this topic has mostly been performed on animal models.
Who Shouldn’t Take Lysine Supplements
Certain people should avoid taking lysine supplements, including:
- People who are pregnant or breastfeeding: There is not enough evidence to know if lysine is safe for these populations.
- People who take calcium supplements: Lysine may increase the amount of calcium your body absorbs, which could potentially lead to hypercalcemia.
- Anyone with lysinuric protein intolerance: This is a rare condition in which the body cannot properly digest lysine and other amino acids.
It’s important to talk to your healthcare provider first before starting any new supplements.
Interactions
Possible food, drug, or supplement interactions with lysine include:
Arginine (another amino acid): Taking a large dose of arginine with lysine may cause lower levels of lysine absorption. This is because some receptors in your body prefer arginine over lysine.
Calcium: Lysine has been found to increase the amount of calcium absorbed in the digestive tract.
It is essential to carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included.
Sources of Lysine
Lysine is an amino acid found in various protein foods, so most people can get all the lysine they need through their diet. Since lysine is so widely available in food, taking a food-first approach to getting enough of it is recommended.
Lysine supplements would only be required if recommended by a healthcare professional due to an underlying health issue. Some people, like those who follow a vegan diet, may have difficulty getting enough lysine.
Food
The best sources of lysine come from animal foods, but it can also be found in some plant-based proteins. The best way to ensure you’re getting enough lysine in your diet is to eat a variety of protein foods, including both animal and plant sources. The recommended daily intake for lysine is 35 milligrams per kilogram (kg) of body weight.
Non-vegan food sources of lysine include:
- Meat
- Chicken
- Dairy products
- Eggs
- Fish
Vegan food sources of lysine include:
- Beans
- Wheat germ
- Lentils
- Nuts
- Soy
- Spirulina
Lysine is present in many different foods. The primary sources are animal products, such as meat and dairy products. For vegetarians and vegans, legumes and wheat germ are good sources of this amino acid.
The following foods will help people meet their daily recommended intake of lysine:
- red meat
- chicken
- eggs
- fish, such as cod or sardines
- beans
- lentils
- Parmesan
- cottage cheese
- wheat germ
- nuts
- soybeans
- brewer’s yeast
- spirulina, a type of algae that manufacturers compress and sell in tablet or powder form
How To Use And Dosage
People usually take lysine by mouth, but they can also apply it to the skin, for instance, to treat cold sores. Experts believe that lysine is most effective when people take it with water on an empty stomach.
Researchers estimate that a 70 kilogram (kg) person needs around 800–3,000 mg of lysine per day. A person’s body weight affects how much they need as follows:
- 12 mg/kg of body weight for adults
- 44 mg/kg for children 11 to 12 years old
- 97 mg/kg for infants 3 to 6 months old
In the United States and other developed countries, most people get enough lysine without needing to make adjustments to their diet. However, people who do not eat animal products, including meat, dairy, and eggs, should ensure that they are getting enough lysine from plant sources.
People recovering from burns or other severe injuries and individuals doing frequent, high-intensity workouts may benefit from a higher-than-average daily intake of lysine.
Experts continue to research effective dosages for clinical purposes. Some studies have shown benefits for doses of 100 mg to 4 g per day. People who use this amino acid to boost their fitness workouts may obtain greater benefits if they take it before sleep or exercise.
Risks
Doctors do not recommend lysine supplements for children or for women who are pregnant or breastfeeding. People taking lysine supplements should monitor their cholesterol levels due to the potential link with higher cholesterol. Anyone with kidney or liver problems should avoid taking lysine supplements.
Summary
Lysine is an essential amino acid that can be found in high-protein foods like meat, nuts, beans, and eggs. It is also available as an oral supplement for those who need it. However, taking a food-first approach to getting enough of it is usually recommended.
It is one of the building blocks of proteins and is necessary for human health. The body does not make lysine on its own, but most people take in enough through their diet to meet basic health needs. Lysine has very few known side effects.
Some research suggests that lysine may be helpful for treating certain conditions, like cold sores and anxiety. More research is needed to determine the full extent of lysine’s safety and efficacy when used for these conditions. Before taking lysine, talk to your healthcare provider about dosage and how to best use the supplement.
Scientific data on some lysine benefits are not yet conclusive. However, many people are exploring the use of lysine supplements, particularly in athletes and people who do not eat animal products. It is best to discuss the use of any supplement with a doctor.
