From the Research
For cold sores, the most effective dose of L-lysine is more than 3 g/d, as doses less than 1 g/d appear to be ineffective for prophylaxis or treatment of herpes simplex lesions, according to the most recent and highest quality study 1. When considering treatment options for cold sores, it's essential to prioritize morbidity, mortality, and quality of life as the primary outcomes.
- The evidence suggests that L-lysine supplementation may be beneficial in reducing the occurrence, severity, and healing time of recurrent herpes simplex infections, but the effectiveness of L-lysine depends on the dose and duration of treatment.
- A study published in 2017 found that L-lysine supplementation appears to be ineffective for prophylaxis or treatment of herpes simplex lesions with doses of less than 1 g/d without low-arginine diets, but doses in excess of 3 g/d appear to improve patients' subjective experience of the disease 1.
- Another study published in 1987 found that L-lysine treatment reduced the frequency, severity, and healing time of recurrent herpes simplex infections, with an average of 2.4 less HSV infections per 6 months 2.
- However, a 2015 review of interventions for prevention of herpes simplex labialis found no evidence to support the efficacy of lysine supplementation in preventing HSL 3. It's crucial to note that patients with cardiovascular or gallbladder disease should be cautioned and warned of the theoretical risks of lysine supplementation, and those who are pregnant, nursing, or have kidney or liver disease should consult their healthcare provider before taking L-lysine supplements. In terms of administration, L-lysine supplements can be taken on an empty stomach with water for best absorption, and the treatment can be continued until the cold sore heals completely, usually within 7-10 days.
- The potential side effects of L-lysine supplementation are generally mild and may include stomach discomfort or diarrhea.
- Overall, while the evidence is not conclusive, the most recent and highest quality study suggests that high-dose L-lysine supplementation (more than 3 g/d) may be effective in reducing the occurrence, severity, and healing time of recurrent herpes simplex infections.