Lysine: Benefits, Dosage & Side Effects

benefits of lysine

Lysine, also known as L-lysine, is an essential amino acid. It is often overlooked, but it is an important part of a healthy diet and plays a crucial role in the general health of the body. 

But what is lysine and why is it so important? From its benefits to the possible side effects of lysine, this article will answer all of your questions about lysine and more! 

We’ll cover:

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What Is Lysine?

Lysine is one of the nine essential amino acids. Amino acids are the building blocks of proteins, so they are important for the body’s growth, tissue repair, and overall function. 

Amino acids cannot be made by our bodies alone, so they can only be gained from foods or supplements. For more information about their function, check out OriGym’s complete guide to amino acids here!

You may be wondering why lysine is also known as ‘L-lysine’. Well, every amino acid has both a ‘D-’ and an ‘L-’ form. The L- form is the most common form found in food and supplements, as it is the form used in most protein synthesis. For that reason, ‘lysine’ and ‘l-lysine’ will be used interchangeably throughout this article.

But what does lysine do? Some of the functions of lysine include regulating calcium levels and providing structure to collagen levels. It also helps transport fat cells to be burned for energy and is used to form carnitine, a substance found in most cells of the body. 

It is one of the key building blocks of muscle tissue and is commonly used by athletes to support lean mass building and the overall health of muscle and bone. While many people will find their diet alone provides them with a suitable amount of lysine, athletes may find it beneficial to take lysine supplements to enhance these benefits and speed up recovery.

L-Lysine Uses

Now that you know what lysine is, you may be wondering, ‘what is L-lysine good for?’

As well as its role in maintaining general growth and repair in the body, Lysine supplements have been used to treat numerous conditions such as:

  • Diabetes
  • Bedsores
  • Schizophrenia
  • High triglycerides levels (fat found in the blood)
  • Canker sores (ulcers)
  • High blood pressure 

L-lysine usage has also been linked to improved athletic performance and muscle strength in athletes. 

Lysine supplements are also taken by those who suffer from lysine deficiency. Symptoms of this include poor concentration, fatigue, nausea, and anemia. If you are experiencing these symptoms but feel you are receiving enough lysine from your diet, you may want to try taking l-lysine supplements. However, it’s best to consult your doctor first.

Although more studies need to be conducted to assess the validity of these claims, the body still needs this essential amino acid regardless. Taking a lysine supplement or eating a high-protein diet is great for the body as it can be used to help growth and overall function.

If you’re struggling to eat enough protein on a plant-based diet, these vegan protein bars are a great way to reap the benefits of lysine without eating meat! 

Benefits Of Lysine

Before we get started on the benefits of l-lysine, we must mention that these health benefits require more research. Lysine won’t necessarily be a miracle cure for any of these health issues you may be facing, but it will likely help alleviate some symptoms. 

#1- Treatment & Prevention Of Cold Sores

One of the most popular health benefits of l-lysine is its treatment of cold sores. 

Cold sores are caused by the herpes simplex virus (HSV). Also called fever blisters, cold sores are usually tiny, fluid-filled blisters that appear on or around the lips. When the blisters break, a scab forms which can be irritating and sometimes painful. 

Cold sores are very common and will usually clear within ten days. However, they can be a source of insecurity and are contagious, which is why many people will take lysine supplements in order to treat them. 

When taken orally as a supplement or used as a lip balm, lysine may be effective in the treatment and prevention of cold sores. A study conducted in 2005 found that an ointment containing lysine reduced the normal duration of cold sores for all but 2 of the 30 male and female participants. The rest of the volunteers saw a significant improvement in the healing of cold sores. 

These findings highlight how lysine benefits the reduction of cold sores and can speed up recovery time. However, the study did not state the exact l-lysine dosage, and it was combined with other ingredients like zinc and herbs.

Although evidence can neither confirm nor deny whether lysine alone is an effective treatment for reducing cold sores, it still may be worth a try if you're prone to suffering from them.

#2- Can Reduce Anxiety

You may have only thought of amino acids as having a physical function in the body. But in fact, they can benefit your mental health too!

Anxiety can be defined as a feeling of unease, such as worry or fear, that can range from mild to severe. It is one of the most common mental health conditions, with 8.2 million cases of anxiety being reported across the UK in 2013. 

There are many proposed treatments for anxiety such as talking therapy or medication. There is even evidence pointing to the mental health benefits of running and other forms of exercise. 

But more recently, there has been research into the use of dietary supplements to treat anxiety. 

A 2010 review revealed that there is strong evidence in favour of the combination of l-lysine and l-arginine supplements, as well as passionflower and kava in the treatment of anxiety disorders. 

L-lysine is believed to help treat anxiety because of its ability to absorb calcium and by partially binding to serotonin receptors. Since serotonin is a mood-stabilising hormone that evokes feelings of happiness, it can therefore reduce anxiety.

Whilst the consumption of lysine has proven to be effective for reducing anxiety in certain studies, it is by no means a conclusive ‘cure’. 

#3- Improves Calcium Absorption & Retention

Another l-lysine benefit is that it may help the body with the absorption and retention of calcium. 

Calcium is an essential mineral for the body. Its main functions include: keeping teeth healthy and building bones, making sure the blood clots normally, and regulating muscle contractions. 

A lack of calcium could lead to rickets in children or osteoporosis for adults. This is a condition that causes the bones to weaken, making them more likely to break. It is therefore important that the body receives enough calcium to stop this from happening. 

Aside from bone health, calcium is also important for the proper function of the heart, muscles, and nerves. It may also be beneficial in protecting the body against cancer, diabetes and in reducing high blood pressure. 

As highlighted above, calcium is important for the body, so ensuring you receive enough of it is crucial. Just like lysine, you can receive enough calcium from a balanced diet. 

Sources of calcium in food include: 

  • Milk, cheese, and other dairy products.
  • Bread and anything with fortified flour.
  • Green vegetables such as collard greens, kale, and okra.
  • Fish with bones you can eat such as pilchards or sardines.

Whilst there is not currently strong enough evidence that l-lysine food sources will reduce the risk of osteoporosis, it certainly may help. That said, it is still important to ensure your body is receiving enough calcium from your diet. 

Like calcium, eating foods high in antioxidants also has many benefits for helping your body’s overall function.

#4- Promotes Wound Healing

Lysine helps support the production of collagen in the body. Collagen is one of the most important proteins and is a building block for skin, muscles, bones, tendons, and ligaments. 

Collagen is present in the body and is what keeps the skin from sagging. But its effectiveness decreases as we age.

As lysine is an amino acid, it is needed to help the body produce collagen which is required to give structure and support to the bones and skin. As such, a benefit of l-lysine is that it helps speed up the healing of wounds. 

A study took 40 rabbits and separated them into two groups, half of which were fed with a diet rich in lysine and arginine. Those who had this diet were found to be able to heal wounds quicker than those who didn’t have lysine and arginine. Furthermore, there was also a reduced healing period of two weeks for the test group.

Studies such as this one therefore indicate that amino acids like lysine can improve the healing process. So if you either have a wound or are particularly susceptible to them, it could be worth adding lysine supplements into your diet. 

#5- Helps In The Treatment of Cancer

Another potential benefit of lysine is that it can aid cancer treatment. 

While radiation and chemotherapy are conventional and effective ways of treating cancer, these methods can sometimes be harmful too. During these treatments, healthy cells in the body are often negatively impacted by the radiation in the same way as harmful cells. 

Because of this, scientists are constantly trying to find more natural cancer treatments. One of the ways this could be done is by using the nutrients in our food which have cancer-fighting properties- including lysine! 

Research was carried out by professors at Florida State University which investigated the reaction of lysine with cancerous cells. It was found that they evoked a chemical process which in simple terms, caused the cancerous cells to destroy themselves while the ‘good’ cells remained intact.

Lysine has great potential for becoming a main component for new cancer treatments. However, many more studies must be conducted to understand the potential benefits of l-lysine for the treatment of cancer.

Eating a balanced and healthy diet full of things like superfruits is another way to reduce the risk of cancer. Like lysine, it is not a definitive cure, but leading a healthy lifestyle is undoubtedly beneficial. 

#6- May Help Schizophrenia Sufferers

There has been some research to suggest that lysine benefits individuals suffering from symptoms of schizophrenia

Just as lysine is thought to alleviate symptoms of anxiety, it can also help those suffering from schizophrenia. This is a serious long-term mental health condition in which a person may not be able to distinguish their own thoughts and ideas from reality.

L-lysine supplements may help decrease these negative symptoms when combined with therapy. It has been proven that schizophernia patients given l-lysine supplements saw an improvement in the negative symptoms of chronic schizophrenia compared to those who didn't. 

However, the exact reasons for why exactly this occurred remains unknown. The efficacy of higher doses and longer treatment periods is also unknown. 

If you think you may be suffering from symptoms of schizophrenia, be sure to consult a doctor.

#7- Strengthens Muscles

A key physical health benefit of l-lysine is that it strengthens muscles. 

Protein is essential for building muscle. Since lysine is an amino acid which is a building block of protein, it can therefore help with muscle growth, particularly if you do a lot of strength training

The body needs lysine to build protein and this growth helps reduce pain and strengthens joints. These amino acids are especially important for athletes as they enhance performance by preventing mental fatigue, modifying fuel during activity, and increasing hormone secretions.

Although lysine may aid muscle growth, ultimately, eating a protein rich diet is what will help you build strong muscles. Check out these cheap whey protein powders for an easy way to incorporate more protein into your diet on a budget. 


Enjoying this article so far? Here’s 3 more that we think you’ll love:

#8- Treats Mouth Ulcers

Anyone who has suffered with canker sores or mouth ulcers, knows how irritating and uncomfortable they can be. They'll often be painful, and require over the counter treatments, or even a visit to the doctor to deal with effectively and efficiently. 

Although there is insufficient evidence for the treatment of canker sores with lysine, it is said that 500mg of lysine taken daily may prevent them, and 4000 mg of daily lysine decreases the duration that canker sores are present in the mouth. 

While further research is needed to test the validity of these claims, it may be worth a try if you’re prone to suffering from mouth ulcers. 

Incorporating some of the foods we'll touch on later in this article is an excellent way to increase your lysine intake without having to worry about supplements or tablets.

#9- Improves Skin

As mentioned above, there are also great l-lysine benefits for the skin. 

Lysine builds collagen in the skin, which is important for maintaining elasticity and a youthful appearance. So eating a diet rich in lysine or taking lysine supplements may help improve your skin!

As l-lysine benefits skin in this way, you may be wondering if it has a role in decreasing the presence of acne. There isn’t a lot of evidence regarding lysine’s direct effect on acne. Instead, a balanced diet may be a better treatment path to go down as opposed to taking l-lysine supplements. 

Eating a healthy, high-protein diet means that you’ll still be receiving suitable amounts of lysine while avoiding foods that may cause breakouts. 

Aside from a protein-rich diet, drinking green tea is also a great way to get healthier-looking skin! 

#10- Boosts Hair Health

Another benefit of l-lysine is that it may influence hair growth. 

Certain amino acids promote hair growth, including lysine. It is present in the hair’s root and is what gives it shape and volume. 

L-lysine may benefit hair because a lack of it in the body can cause hair loss. By receiving enough lysine from your diet or supplements, this may have the opposite effect and promote hair growth!

Are you looking to grow your locks? You may not have thought it, but one of the benefits of eating eggs is that they can promote hair growth! 

L-Lysine Food Sources

So, now that you know the many benefits of l-lysine, you may now be wondering how to incorporate more of it into your diet. 

There are many l-lysine food sources. However, it is largely present in protein-rich foods, mainly meat and dairy products. 

Some key plant and animal products that contain lysine are:

  • Meat, such as beef, lamb, pork, and poultry.
  • Fish, mainly cod and sardines.
  • Parmesan cheese
  • Eggs
  • Beans
  • Nuts
  • Wheat germ
  • Spirulina (freshwater algae)

But don’t worry, for those who don’t consume animal products, there are plenty of vegan and vegetarian alternatives! Some plant-based l-lysine foods include quinoa, lentils, and soy milk. 

If you’re vegan and looking to get more protein into your diet, stocking up on these high-protein vegan snacks is an easy way to do so!

Nutritional Value Of Lysine

As well as knowing what the main lysine foods are, it is also useful to know its nutritional breakdown. 

Food and plant products are considered to have a sufficient level of lysine if it has at least 51mg of lysine per gram of protein. 

A ¼ level teaspoon serving of pure lysine powder should provide you with around 435 mg of lysine. This is a suitable amount and can be added to smoothies or shakers along with water or fruit juice to provide you with a good l-lysine dosage.

It’s always best when purchasing powders and tablets to be aware of added ingredients. Pure lysine without flavourings is better as it reduces the risk of an increased sugar or carbohydrate content. 

While powders can be added to yogurts and smoothies, this will naturally increase the calorie content of something that doesn’t have any to begin with. It’s understandable that you may want to make the l-lysine powder sweeter, but be aware of diluting it too much as you may not receive the optimal lysine benefits.

If you’re looking to increase your protein intake without the added carbs, check out these low carb protein powders to add into your shakes and smoothies. 

If you’re worried about increasing calories but still want to take a l-lysine supplement, then capsules are a good option. Certain lysine supplements have as much as 1000 mg of the amino acid in a single capsule. This means you’ll be taking a pure form of lysine without having to add it to anything, and so you’ll receive more health benefits of l-lysine. 

When taking lysine supplements or powder, aim for consuming it in its purest form rather than with products that are high in fat and sugar.

Lysine Dosage

Now you know the benefits of lysine, you may be eager to start taking it. But before you do, let’s consider the question, ‘how much lysine is too much?’, in order to avoid the possibility of a lysine overdose. 

The answer is that it depends on several factors! The correct l-lysine dosage depends on the height and weight of the individual. Most people should receive enough lysine from a balanced diet alone so shouldn’t need to take lysine supplements or greatly increase their consumption of l-lysine foods. 

However, those who do not consume animal products such as meat and dairy must ensure they receive a suitable amount from other l-lysine food sources, as we have outlined above. 

Though further research is required into the adverse effects of lysine, it is generally believed to be safe. While there hasn’t been recorded instances of lysine overdoses, this doesn’t mean to say you shouldn’t be careful, especially when taking lysine supplements. 

According to this review, the optimal l-lysine dosage for Herpes simplex prophylaxis isn’t known, but a reasonable dose is between 500-3000 mg daily. 

The estimated dietary requirement for someone weighing 154 pounds is around 800-3000 mg per day. 

Here is a rough idea of how much lysine is contained in certain foods:

  • ½ can of tuna contains around 2400 mg of lysine.
  • 3 ounces of chicken (baked light meat) contains around 2232 mg of lysine.
  • 3 ounces of cheese contains around 1650 mg of lysine.
  • 1 cup of granola contains around 500 mg of lysine.

These numbers are by no means set in stone, as this may change depending on the individual product or brand. When it comes to lysine dosage, most people will receive a sufficient lysine dosage without even realising it.

When To Take L-Lysine

While there isn’t necessarily a ‘best’ time to take l-lysine supplements, they are believed to be most effective when taken with water on an empty stomach. 

If you’re wondering when to take l-lysine supplements, morning time after first waking up is ideal. You could make it part of your routine before your morning black coffee

In terms of how to take it, the body obtains lysine through the mouth, but it is also commonly applied to the skin in the treatment of cold sores. 

Alternatively, if taking a lysine supplement isn’t for you, but you still want to increase your consumption, ensure you have three set high-protein meals a day to receive a suitable amount of lysine. 

Possible Side Effects Of Lysine

Generally, lysine is considered relatively safe if you remain within the recommended quantities. However, taking too much of it could result in you experiencing some of the negative side effects of l-lysine.

Common side effects of l-lysine include:

  • Diarrhoea
  • Cramps
  • Abdominal Pain
  • Gallstones
  • Nausea
  • Kidney Issues

Not all side effects are known, so be aware that others not included in this list may occur. Lysine is considered generally safe when taken for up to a year. It should also be mentioned that these reported l-lysine side effects result from supplements, not natural sources like food or plant products. 

If you suffer from kidney or liver impairment, it’s best to be cautious before taking lysine supplements. 

If you experience signs of an allergic reaction after taking lysine supplements, seek medical help immediately. Depending on the severity of your allergy, if you have difficulty breathing, hives (itchy red rash), or the lips, face, tongue, or throat swell, you’ll need emergency help. 

If you begin to experience even mild issues after taking lysine supplements, contact your doctor for advice.

Currently, there isn’t enough research into the potential side effects of l-lysine and safety of taking supplements during pregnancy. It is therefore best to avoid taking l-lysine supplements if you’re pregnant or breastfeeding. 

It is still safe for you to receive this amino acid from l-lysine food sources. However, these high-protein foods should be eaten in moderation to avoid weight gain or the development of health conditions. If you’re pregnant, consult your GP for advice before taking any lysine vitamins or supplements so they can help decide what’s best for you.

Purchasing Lysine

As mentioned throughout this article, most people will receive a satisfactory l-lysine dosage from a high-protein diet. However, if you’re an athlete or are concerned you aren’t getting enough lysine to achieve the alleged benefits, you may want to try taking some l-lysine supplements. 

Before starting taking any kind of supplement, even something like a BCAA tablet, you should always be aware of exactly what you are taking. And taking lysine vitamins or supplements is no exception. 

A few questions to consider before beginning your regimen are:

  • Do I really need to increase my intake?
  • Can I take it alongside other medications?
  • Should I take it as a pill, liquid, or powder?
  • How long should I take it for? 

It is unlikely you’ll experience any adverse effects just from taking vitamins or supplements, but as always, it’s best to be aware. 

Making sure to read product labels before purchasing is crucial in ensuring the product is right for you. Read for scientific claims supporting the product's purpose, pay attention to the expiration dates, and ensure it’s been tested for safety and purity. Check the supplement fact label too, as this will include important information about any added ingredients and what exactly is contained within each serving.

When shopping around for products, the internet is a great tool. This allows you to compare standards and prices, as well as get an idea about what’s on the market. However, when buying vitamins and supplements, be sure to only research credible companies and brands.

If you do end up buying off the internet, always check out customer reviews before purchasing items, especially when it comes to health products. 


Can I take L-lysine every day?

Lysine is generally considered safe to take every day.

However, while it’s unlikely you’ll experience many l-lysine side effects, if taking supplements, you should always stick to the recommended dosage. 

There is a reason many vitamins and supplements are taken only once a day because you will receive a satisfactory amount from them, especially if taken alongside a high-protein diet. 

Ultimately, consuming lysine every day is not going to be harmful to your body if you remain within the recommended l-lysine dosage. 

Can I take lysine supplements with other medications?

If you’re wanting to start taking lysine supplements, you should first check how it will interact with any other medication you may currently be taking. 

There’s a chance l-lysine may react with aminoglycosides, a type of antibiotic given by doctors to treat serious infections. In some cases, this may result in damage to the kidneys.

Furthermore, as lysine increases the absorption of calcium as mentioned above, you should be aware of how much calcium you consume. Whilst you can receive many benefits from a suitable level of calcium, too much of it may actually result in weaker bones, kidney stones, and heart issues. 

If you’re taking medication, be sure to consult your doctor before taking lysine supplements. However, don’t worry if you’re only consuming l-lysine through your diet, as these adverse effects refer to taking supplements. 

You should only be asking ‘how much lysine is too much?’ if you’re taking multiple capsules a day and exceeding the recommended dosage alongside medication.

Can lysine help with wrinkles?

People are always searching for ways to look younger, especially natural ways to do so. A possible aid in maintaining a youthful appearance could be down to lysine. However, it is not a miracle cure!

L-lysine is required in the production of collagen, which is what keeps your skin firm and structured. As we age, our levels of collagen decrease, which causes our skin to sag and wrinkle. 

As we have discussed, research is still needed into whether lysine benefits aging skin. But nonetheless, it is still important for producing collagen, so having enough of it in your diet is important. 

Wrinkles are a natural part of the aging process and even with the best skin care routine, you will eventually get them. However, there are things you can do to prevent premature wrinkles such as moisturising daily, staying hydrated, and not smoking. There are even benefits of running for your skin!

It may not be the answer you want but lysine supplements are unlikely to reduce the appearance of wrinkles if you already have them! However, if you want to prevent premature wrinkles, it may be best to increase your lysine intake sooner rather than later. 

Before you go!

So, we hope that you now have a better understanding of lysine and what it can do for your body. Hopefully the knowledge you’ve gained about the benefits of l-lysine, the side effects of l-lysine, and everything else has helped you decide whether it’s something for you. 

If this has sparked your interest in health and fitness, why not deepen your knowledge by taking a personal training course with OriGym? Enquire today to see how it could kickstart your dream career in fitness!

You can also download our free prospectus here to find out more about OriGym and the fitness courses we offer. 


Mailoo, Venthan J.; and Rampes, Sanketh, ‘Lysine for Herpes Simplex Prophylaxis: A Review of the Evidence’ in Integrative Medicine: A Clinician’s Journal (June 2017, Vol. 16, Issue 3) 42–46

Singh, Meenu et al., ‘Medicinal Uses of L-Lysine: Past and Future’ in International Journal of Research in Pharmaceutical Sciences (January 2011, Vol. 2, Issue 4) 637-642

Singh, Betsy B. et al., ‘Safety and effectiveness of an L-lysine, zinc, and herbal-based product on the treatment of facial and circumoral herpes’ in Alternative Medicine Review (June 2005, Vol. 10, Issue 2) 123-7. PMID: 15989381

Chi, Ching-Chi et al., ‘Interventions for prevention of herpes simplex labialis (cold sores on the lips)’ in Cochrane Database System Review (August 2015, Issue 8) 1-120. 

Gaby, Alan R., ‘Natural Remedies for Herpes Simplex’ in Alternative Medicine Review (June 2006, Vol. 11, Issue 2) 93-101. PMID: 16813459

Lakhan, Shaheen E.; and Vieira, Karen F., ‘Nutritional and herbal supplements for anxiety and anxiety-related disorders: systematic review’ in Nutrition Journal (October 2010, Vol. 9, Issue 42) 1-14, doi: 10.1186/1475-2891-9-42

Sinha, Shivam; and Goel, Satish Chandra, ‘Effect of amino acids lysine and arginine on fracture healing in rabbits: A radiological and histomorphological analysis’ in Indian Journal of Orthopaedics (October-December 2009, Vol. 43, Issue 4) 328-334. 

Written by James Brady

Fitness Writer & Enthusiast

James graduated with an MA in Creative Writing from the University of Manchester. His desire to find a place where he could combine his passion for writing and love of fitness is what brought him to OriGym. He believes his passion for daily exercise, especially running, is imperative in keeping him motivated and productive. As a result, he has a particular interest in the psychology of health and fitness and the relationship between physical and mental health. Outside of work, James enjoys reading, swimming, writing short stories, watching classic movies and has a keen interest in journalism and filmmaking.

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