Lysine and cold sores

What 4 graded rows on lysine agree on for cold sores, and where they differ. Counted side by side, never averaged.

Consensus finder Rows from the Lysine page, reviewed Oct 21, 2026 How it decides

What the rows agree on

Each block and row is one graded row from the Lysine page, with its PubMed record.

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Cold sores4

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Lysine and cold sores

4 rows · 179 people

Split. 1 row found an improvement, 1 found no difference and 2 had mixed results.

No difference or mixed

Improved

Each block is one evidence row, sized by how many people it enrolled, with its grade inside. Outlined: mixed results.

Grade D× 4

Rows: 4
Trials: 4
People: 179

Where they differ

From the rows

Trial sizeWhen published

The best-graded row, grade D, is a crossover trial of 65 people (1980) and reported mixed results.

The row that found an improvement was larger: 52 people, against 21 people for the row that found no difference.

The row that found an improvement is newer (1987) than the row that found no difference (1984).

2 rows with mixed results are left out of this comparison.

The rows

1 improved · 1 no difference · 2 mixed

Grade DRecurrent herpes simplex: outbreaks, severity and time to clear · Improved
RCT · n 52 · 1987 · Adults with frequently recurrent herpes simplex
1,000 mg L-lysine three times daily (3 g/day) · 6 months
The lysine group had an average of 2.4 fewer outbreaks, milder symptoms and faster healing than placebo.
Row on the Lysine page · PubMed 3115841 (opens PubMed)
Grade DRecurrent herpes simplex: frequency, duration and severity · No difference
RCT · n 21 · 1984 · Healthy adults with frequently recurring herpes simplex
400 mg three times daily (1.2 g/day) · Not stated in the abstract
No substantial benefit for outbreaks in progress or for preventing recurrences.
Row on the Lysine page · PubMed 6419679 (opens PubMed)
Grade DRecurrent cold sores (herpes labialis) · Mixed
Crossover RCT · n 65 · 1980 · Adults with recurrent herpes simplex labialis
1,000 mg/day · 12 weeks lysine, 12 weeks placebo
No overall effect on recurrence rate, healing or lesion appearance, though more people were recurrence-free on lysine than on placebo (p = 0.05).
Row on the Lysine page · PubMed 6153847 (opens PubMed)
Grade DRecurrent herpes simplex: recurrence rate · Mixed
Crossover RCT · n 41 · 1984 · Non-immunocompromised adults with recurrent herpes simplex
624 or 1,248 mg/day · Crossover periods (length not stated in the abstract)
1,248 mg/day showed evidence of fewer recurrences; 624 mg/day did not. Neither dose shortened healing time.
Row on the Lysine page · PubMed 6435961 (opens PubMed)

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