What is the use of L-lysine (Lysine) supplement?

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Last updated: April 25, 2025View editorial policy

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From the Research

Lysine supplements are primarily used to prevent and treat cold sores caused by the herpes simplex virus, with a recommended dosage of 1,000-3,000 mg daily, divided into multiple doses, as supported by the most recent study 1.

Key Points

  • Lysine is an essential amino acid that the body cannot produce on its own and must be obtained through diet or supplements.
  • It works by inhibiting arginine, another amino acid that the herpes virus needs to replicate.
  • Besides cold sore management, lysine supplements may support calcium absorption, collagen formation, and protein synthesis in the body.
  • Food sources of lysine include meat, fish, dairy, eggs, and legumes.
  • People with herpes infections, those with diets low in lysine, or individuals with specific health conditions may benefit most from supplementation.
  • Side effects are generally mild but can include gastrointestinal discomfort, and those with kidney or liver disease should consult a healthcare provider before taking lysine supplements, as noted in 2.

Dosage and Administration

  • A typical dosage ranges from 1,000-3,000 mg daily, divided into multiple doses, with 1,000 mg taken at the first sign of a cold sore outbreak and continued for 7-10 days.
  • Doses in excess of 3 g/d appear to improve patients' subjective experience of the disease, as reported in 1.

Mechanism of Action

  • Lysine inhibits the replication of the herpes virus by suppressing the production of arginine, which is necessary for viral replication, as demonstrated in 3.

Special Considerations

  • Patients with cardiovascular or gallbladder disease should be cautioned and warned of the theoretical risks of lysine supplementation, as noted in 1.
  • Those with kidney or liver disease should consult a healthcare provider before taking lysine supplements due to the potential for nephrotoxicity, as mentioned in 2.

References

Research

Lysine for Herpes Simplex Prophylaxis: A Review of the Evidence.

Integrative medicine (Encinitas, Calif.), 2017

Research

[Lysine and human nutrition].

Annales de biologie clinique, 1991

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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