What's the Maximum Lysine Dosage for Cold Sores?

Cold sores, also called fever blisters or herpes simplex labialis, are small, painful, fluid-filled blisters that typically appear on or around the lips and mouth. Cold sores are caused by the herpes simplex virus type 1 (HSV-1). They are contagious and spread through close contact with an infected person.

While there is no cure, cold sores usually clear up on their own within one to two weeks. Prescription antiviral medications like acyclovir (Zovirax), famciclovir, valacyclovir (Valtrex), and penciclovir (Denavir) can help manage cold sore outbreaks. Many people also seek natural or over-the-counter (OTC) remedies like lysine supplementation.

This article will cover the maximum lysine dosage for cold sore treatment as well as the safety and effectiveness of this supplement.

What Is Lysine?

Lysine or L-Lysine is one of the nine essential amino acids. Amino acids are the building blocks of proteins and are found in every cell in the body. The human body cannot make essential amino acids, such as lysine, and must obtain them from dietary sources.

Lysine is found in protein-rich foods like meat (beef, pork, chicken), fish, eggs, legumes, soybeans, and dairy products (milk, yogurt, cheese). Most people get enough from diet, but those with restrictive diets or certain medical conditions may benefit from supplements.

Lysine has the following functions and health benefits in the body:

Helps in calcium absorption and maintenance of bone health.
Supports a healthy immune system with a role in antibody production.
Lowers cortisol hormone levels and controls stress and anxiety.
Plays a role in protein synthesis, including tissue growth and repair, and the formation of hormones and enzymes.

How Lysine Works For Cold Sores

Lysine is most commonly used as an oral supplement to prevent cold sores. Research indicates that lysine works by competing with arginine, a non-essential amino acid important for HSV replication. Reducing arginine may limit viral growth and the severity or frequency of cold sore outbreaks.

Potential benefits of lysine for herpes simplex virus infections include:

Less frequent outbreaks of cold sores.
Fewer herpes labialis lesions (cold sores or fever blisters) during outbreaks.
Faster pain relief.
Reduced healing time.
Improved subjective response (lower perceived severity and discomfort during the illness).

Does Lysine Really Help Cold Sores?

Research on L-lysine supplementation for the prevention and treatment of cold sores (herpes simplex labialis) has produced mixed results. The findings are as follows:

Low doses (less than 1 gram per day) may be ineffective unless combined with a low-arginine diet.
Higher doses (more than 3 grams per day) may reduce symptoms and outbreaks.
One study found that 1,000 mg a day significantly reduced cold sore recurrence in those with frequent cold sore outbreaks.
Stopping lysine supplements caused a substantial increase in the frequency of cold sore outbreaks.

A study that enrolled people with cold sores, canker sores, and genital herpes found that an average dose of 936 mg of lysine daily resulted in:

84% of patients saw fewer cold sore outbreaks.
90% of patients saw a faster healing process
88% of patients considered supplemental lysine an effective treatment for a herpes infection.

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How Much Lysine Should You Take For Cold Sores?

Prevention

You can take between 500 mg and 1,000 mg of lysine every day to reduce the recurrence rate of cold sore outbreaks.

Active Outbreak

The recommended doses of lysine supplements range from 1,000 mg to 3,000 mg per day to treat an active cold sore outbreak. You should take the supplement in divided doses, for example, 1,000 mg three times a day (two 500 mg lysine pills in the morning, afternoon, and evening) to reduce the risk of gastrointestinal side effects.

Maximum Dosage

Taking up to 3,000 mg per day of lysine supplements is considered generally safe for most people.

How To Take L-Lysine

Dosage Forms

Lysine supplements are available in capsule and tablet form, liquid form, and topical form (creams and powders).

Some lysine supplements contain additional ingredients like vitamin C, vitamin E, zinc, quercetin, and propolis extract, which may have potential immune system benefits.

Best Practices

Take lysine on an empty stomach.
Some experts recommend taking it at bedtime.
For prevention, take 1 gram of lysine daily for up to one year.
For treatment of an active outbreak, take lysine three times a day for 7-14 days.

Is 6,000 mg Lysine for Cold Sores Safe?

While doses up to 6,000 mg/day have been studied without serious side effects, such high amounts should only be used for the short term and under medical supervision.

Safety and Side Effects

High doses of lysine in supplement form can cause digestive issues like stomach pain, nausea, and diarrhea. Lysine is also linked to an increased risk of kidney problems, liver disease, and gallbladder issues.

Always consult a healthcare provider before taking dietary supplements, including lysine, especially if you are pregnant, breastfeeding, or managing a chronic condition such as liver disease, kidney disease, or gallbladder disease.

Remember, the U.S. Food and Drug Administration (FDA) does not regulate supplements like it regulates prescription and over-the-counter medications.

Tips To Prevent Cold Sores

The following can help prevent cold sores and manage symptoms during an outbreak:

Avoid Cold Sore Triggers

Known triggers for herpes outbreaks include stress, fatigue, exposure to the sun or wind, hormonal changes, and skin injuries. Avoiding these triggers can reduce the frequency of outbreaks.

Dietary Modifications

Limit high-arginine foods like nuts, pumpkin seeds, chocolate, squash, oats, wheat, and spirulina powder.

Lip Balms and Sunscreen

Use topical cold sore treatments, lip balms, and sunscreen to reduce discomfort, such as docosanol (Abreva), lidocaine, benzocaine, and zinc oxide.

You can also use moisturizing creams to prevent dryness, cold compresses or warm compresses to relieve pain, and over-the-counter pain relievers such as acetaminophen and ibuprofen.

Frequently Asked Questions

How Fast Does Lysine Work For Cold Sores?

Studies have found that lysine can reduce healing time to 5 days or less (compared to 6-15 days without lysine).

Can I Take Lysine With Other Medications?

Check with your doctor before taking lysine with other medications. Lysine can interact with calcium supplements and certain drugs used to treat chronic constipation (prucalopride) and irritable bowel syndrome with constipation (tegaserod).

Is Abreva or Lysine Better For Cold Sores?

Abreva (docosanol) is generally considered more effective than topical lysine for treating cold sores. Abreva is an FDA-approved antiviral medication that directly targets the herpes simplex virus, which is responsible for causing cold sores.