Is monolaurin better supported than lysine for cold sores?
The cited sources do not establish that monolaurin is better. Lysine has small human trials with inconsistent results; the cited monolaurin evidence is laboratory research rather than proof of a cold-sore benefit in people.1235 This is not a head-to-head treatment comparison.
What the lysine trials found
A 1987 placebo-controlled trial reported fewer recurrent HSV episodes and improvements in symptom severity and healing among participants who completed treatment. Twenty-seven lysine recipients and 25 placebo recipients completed the six-month study. The tested regimen was 1,000 mg three times daily.1 Those are historical study details, not a dosing recommendation. The abstract reports completers; it does not establish the dropout percentage or analysis method claimed in our previous version.
A 1980 crossover trial in 65 patients tested 1,000 mg daily. It found no overall reduction in recurrence rate or improvement in lesion healing, although more patients were recurrence-free during lysine treatment than during placebo treatment.2 That finding does not establish that clinicians can identify who will benefit.
DiGiovanna and Blank's 1984 placebo-controlled trial studied 21 patients using 400 mg three times daily. It detected no substantial benefit for episode frequency, duration or severity.3 Our previous version incorrectly attributed these results to Simon and colleagues' 1985 letter.
Mechanisms and their limits
Lysine has been investigated in relation to arginine-dependent HSV replication, including cell-culture work discussed in the clinical literature.2 A proposed biochemical explanation does not establish that supplements or an arginine-restricted diet prevent outbreaks.
Monolaurin and related lipids have been studied for laboratory antiviral activity and effects involving viral envelopes.45 The 2020 GML study is not a human cold-sore trial. Describing its mechanism as more direct does not demonstrate better healing, fewer recurrences or greater safety.
Evidence side by side
| Question | Lysine | Monolaurin |
|---|---|---|
| Human outcomes | Small controlled HSV trials with differing results.123 | No human cold-sore benefit established by the sources cited here.5 |
| Mechanistic evidence | Does not resolve the inconsistent clinical findings. | Laboratory antiviral findings do not establish an oral or topical treatment. |
| Combination use | These sources do not test whether taking lysine and monolaurin together improves outcomes. | |
What this comparison cannot tell you
The cited trials do not establish a reliable lysine regimen, a clinically effective monolaurin regimen, or a benefit from combining them. A comparison of mechanisms cannot substitute for clinical outcomes. This article summarizes research and does not recommend either supplement for treatment or prevention.
Read the cold-sore evidence discussion and the safety and dosage limitations for additional context.