Suppressive acyclovir,
does it really help with Prevention of clinical recurrences during treatment?
research showsThe grade is C. Across nine parallel acyclovir-versus-placebo trials with 2,049 participants, the pooled risk of at least one clinical recurrence was reduced, RR 0.48 (95% CI 0.39 to 0.58); the small-study-adjusted RR was 0.61 (0.49 to 0.75).
ads claimDo not mix suppressive therapy with episodic treatment or genital disease with labial or ocular herpes.
Useful facts when choosing a product
- The regimen was 400 mg twice daily.
- Each period lasted 12 weeks.
- Kroon attrition and direct funding could not be verified; four related trials were Wellcome-funded.
What the research actually shows
Cochrane reviewed 26 trials with 6,950 participants, including 14 acyclovir-placebo trials. Nine parallel trials with 2,049 participants yielded RR 0.48 (95% CI 0.39 to 0.58), and adjustment for small-study effects yielded RR 0.61 (0.49 to 0.75). The evidence included small trials and trials with at least 15% post-randomization attrition. Twenty-two trials disclosed pharmaceutical funding, which was recorded under independence rather than counted again as a design defect.
Why this is classified as C (54)
Pooled benefit with small-study and at-least-15% attrition defects gives C with 54 points.
Counterpoint. Suppression during dosing is not eradication of latency.
Rejudgment record. Cross-check applied — Pooled recurrence reduction with small studies and at least 15% attrition
| Endpoint | H | Hard endpoint - actual events such as death |
| Replication | R1 | Single confirmatory trial |
| Independence | I1 | Mixed funding sources |
| Effect size | E+ | Meets the clinically important threshold |
The scoring table and the verdict agree (C).
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| Prevention of genital recurrences during treatment | C | Recurrences were fewer during acyclovir. |
Cross-check — Codex and Claude
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Study 1 | Randomized double-blind placebo-controlled crossover trial | 24 | Direct Kroon funding could not be verified; four of five similar crossover trials were Wellcome-funded | Clinical recurrence and recurrence-free status over 12 weeks | 17/24 recurrence-free; 9 recurrences on acyclovir versus 18 on placebo | Pivotal direct trial |
Receipt — 2 References
All 2 cited sources were verified for existence at the original page (as of 2026-08-07).
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-07 · Corrections: none
Cite this verdict
[Chamgap] Suppressive acyclovir x prevention of recurrent genital herpes — Evidence Grade C·54. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/immunity/suppressive-acyclovir-recurrent-genital-herpes/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.