L-Lysine is an essential amino acid that has a number of different functions in the body. It is involved in protein and collagen synthesis, supports immune function, and contributes to energy metabolism.
As an essential amino acid, L-lysine cannot be made by the human body. It must be obtained through foods or supplements. Most people are able to get sufficient amounts of this nutrient from their diet, without using supplements.
The best food sources for Lysine include legumes, meat, dairy products, fish and eggs. Vegans and vegetarians who do not eat these foods may be at risk of deficiency and may require supplements to maintain adequate levels.
Lysine 1000 mg tablets are also used to boost health, support energy levels and combat signs of aging. This supplement is also used medicinally to alleviate cold sores caused by the herpes simplex labialis virus.



- Promotes health skin & bones
- Boosts immunity & antibody production
- Supports tissue repair & hormone balance
Why Use Lysine Tablets?
L-Lysine is an amino acid that the body uses to produce a number of different proteins. As a result, it has a wide range of functions in the human body.
Some of the roles of this amino acid are to support proper nitrogen balance, facilitate calcium absorption and retention and to regulate nitric oxide levels.
Lysine has also been shown to inhibit glycation, which refers to the bonding of sugars to proteins and fat molecules. Glycation has been implicated as a potential cause for premature aging. Individuals with metabolic syndrome and poor blood glucose regulation are at a higher risk of glycation.
Taking lysine 1000 mg pills may help to reduce the number of glycated proteins that occur in the body, which could have significant benefits for general health and well-being.
In research studies, consuming l-lysine supplements has been shown to promote relaxation in those with low dietary intake of this nutrient. It may also help to balance stress hormone response, particularly in combination with L-Arginine.
Bodybuilders may also use oral lysine tablets or powders to support athletic performance and lean muscle mass growth. It has also been used to support fertility and hair growth in men.
Lysine deficiency is a rare condition, but can affect vegans and individuals who do not get enough protein-rich foods in their diet. Certain conditions may also result in lysine deficiency; burn victims often require more of this amino acid to support the healing process.
Lysine 1000 MG Pills for Cold Sores
One of the most common uses for lysine 1000 mg tablets is to treat or prevent cold sores caused by the herpes virus. While it has been studied for this purpose, the FDA has not approved lysine as a treatment for cold sores
The Natural Medicines Database classifies Lysine as possibly effective for the treatment of herpes labialis, or cold sores. NMD notes that taking 1000 to 1248 mg of this amino acid each day appears to lower the severity, duration and recurrence of these infections.
According to NMD, not all research studies conducted on this topic have found lysine to be effective for herpes infections. No significant results were observed in one study when 400 mg of L-lysine capsules were taken three times a day.
The University of Maryland Medical Center states that consistently taking Lysine could prevent cold sore infections, due to the antiviral properties of this amino acid.
However, they note that the majority of experts do not believe that it can treat or cure herpes. According to UMM, it may only improve the symptoms or cut down on recurrences. [1]
One double-blind, placebo-controlled trial found Lysine effective for lowering the severity, duration and occurrence of recurring herpes simplex infection. This study gave subjects 1,000 mg of Lysine three times daily for a period of six months. [2]
There is not enough evidence to rate the effectiveness of Lysine for canker sores, diabetes or stress, according to the Natural Medicines Database. More research is required to support these uses for Lysine.
How Much L-Lysine to Take
To support regular body function, the USDA has established a recommended dietary allowance for L-lysine of 38 mg/kg of bodyweight, for adults aged 19 and old.
This means that the RDA for a 50 kg adult would be 1900 mg. For a 75 kg adult, this would amount to a 2850 mg dietary intake.
As a dietary supplement, oral lysine tablets typically come in dosages of between 500 – 1000 mg per day. Many clinical trials have used doses of 1000 to 3000 mg daily for herpes infections.
The Natural Medicines Database rates this supplement as possibly safe when taken by mouth for as long as one year or if used topically on a short-term basis.
In children, the dosage is determined by the body weight of the child. In adults, the recommended dosage can also vary by numerous factors, such as the purpose for taking it. Consult with a doctor to determine what the best dose for you is.
A variety of brands sell oral Lysine tablets. Some popular brands sold on Amazon.com include Nature Made, Puritan’s Pride, Quantum, NOW Foods and Solgar.
Lysine Tablets Reviews
On WebMD, consumers rated the effectiveness of Lysine supplements highly overall. Reviewers mention that the Lysine helps them prevent cold sores or reduce the duration after it starts.
Numerous reviewers noted that Lysine worked better for them than other treatments for cold sores. Many reviews specified that the Lysine was particularly beneficial when taken upon the first tingling sensation of a cold sore. The reviews discuss different doses being used. [3]
On Amazon.com, reviews of Now Foods L-Lysine 1000 mg tablets are generally positive. This product has received a 4.4 out of 5-star rating, based on 291 customer reviews.
Reviewers commented that the supplements helped them prevent the cold sore or shortened the duration. They also noted that it worked better for them than other common cold sore treatments.
Many of the negative comments referred to the size of the pill being too large. One user stated that the pills from this brand were harder to swallow than those from other brands and that they were not as effective as alternatives that she had used. [4]
Potential Side Effects of Lysine Tablets
Lysine is well tolerated in general, although it is associated with some adverse reactions. Lysine tablets side effects include stomach upset, renal function interference, gallstones, high cholesterol and abdominal cramping.
According to the Natural Medicines Database, there is insufficient evidence to determine the safety of Lysine supplements for pregnant and nursing mothers.
However, the USDA does recommend higher intake of this nutrient for women who are pregnant and breastfeeding. Your doctor may recommend a prenatal vitamin that includes this amino acid or may recommend that you eat more lysine-rich foods.
This supplement may interact with 5-HT4 agonist drugs and calcium supplements. The risk of side effects may be increased if used by patients with osteoporosis, kidney disease and lysinuric protein intolerance. It may also interfere with diagnostic cancer imaging lab tests.
Some research supports the effectiveness of Lysine 1000 mg tablets for its most common use of preventing or reducing cold sores caused by the herpes infections. User reviews also demonstrate its efficacy, although the product does not work equally well for everyone.
Consult with a doctor to learn more about your treatment options and to determine whether Lysine supplements are appropriate for you.
Article last updated on: March 12th, 2018 by Nootriment