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Antiviral

Enfuvirtide

The first HIV entry inhibitor — a 36-amino-acid peptide that blocks viral fusion.

L5Repeated human trialsApproved for a specific indication · FDA (US)Approved
How settled this rating is:
high confidence in the current evidence rating
Routes studied:
Subcutaneous injection
Also known as:
Fuzeon, T-20
Last reviewed:
2026-08-23
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Evidence passport

Enfuvirtide

A one-screen evidence identity for this compound. These fields describe research maturity, confidence and legal status. They are not a safety guarantee, efficacy percentage or recommendation.

Reviewed 2026-08-23
Evidence level
L5Repeated human trials
Confidence
High confidence in rating
Regulatory status
Approved for a specific indication · See jurisdiction details
Development status
Approved

Evidence strength

Human efficacy evidence82 of 100 evidence strength

Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.

Human safety evidence78 of 100 evidence strength

Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.

The 0-100 values rate the strength and maturity of evidence, not how effective or safe the compound is.

Evidence base
Includes human studies
Furthest established stage
Approved
Human research maturity
Approved antiretroviral, now largely historical in practice
Source curation
Sources fully curated

Routes recorded

SC injection

Overview

Human efficacy evidence strength82 of 100 evidence strength

Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.

Preclinical (animal / lab) evidence strength78 of 100 evidence strength

Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.

Human safety evidence strength78 of 100 evidence strength

Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.

How to read these scores

Every number here rates the evidence, not the compound. They are editorial 0-100 strength ratings, not percentages, and not a rating out of five stars.

  • Human efficacy evidence strength — Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
  • Preclinical evidence strength — Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
  • Human safety evidence strength — Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number. A score of 80 does not mean “80% safe”.
  • Evidence level (L0-L5) — the strongest type of study behind the compound, from anecdote (L0) to large replicated human trials (L5). It is a description of the study evidence, not a quality, safety or recommendation rating.
  • Confidence — how likely we think it is that this rating changes as new research lands. Low confidence means the picture is unsettled, not that the compound is bad.

None of these ratings is medical advice, a safety guarantee, or a recommendation to use anything. How we grade evidence.

How far human research has progressed: Approved antiretroviral, now largely historical in practice

Routes & formulations

Studied / approved routes

SC injection

The approved product is a twice-daily subcutaneous injection as part of combination antiretroviral therapy.

Route availability is not evidence of efficacy, and evidence from one route does not transfer to another. The Registry never provides dosing or sourcing information.

Peptide lifecycle

  1. Discovery

  2. Preclinical

  3. Phase I

  4. Phase II

  5. Phase III

  6. Approved

Approved

What it is

A synthetic peptide mimicking part of the HIV gp41 protein, blocking the conformational change the virus needs to fuse with human cells.

What people claim

  • Reduces viral load in treatment-experienced HIV-1 patients as part of combination therapy

What the evidence actually says

Randomised trials in heavily treatment-experienced patients supported its approval and proved that a peptide could be a viable antiviral class. Newer, easier antiretrovirals have since narrowed its practical role.

Useful next reads based on this compound — not recommendations.

Human evidence

  • Pivotal randomised controlled trials in treatment-experienced HIV-1 infection.

Preclinical evidence

  • Viral fusion biology and gp41 peptide-inhibition studies.

Animal and cell findings are Level 1–2 evidence.

Mechanism and pathways

  • Binds gp41 and prevents the six-helix-bundle formation required for viral-cell membrane fusion.

Safety and unknowns

  • Injection-site reactions are near-universal and are the dominant tolerability issue.
  • Labelled considerations include hypersensitivity reactions and a pneumonia signal observed in trials.

Cancer relevance

This section covers questions raised by how the compound works in the body, plus anything regulators and trial teams keep an eye on. It is not a statement that this compound causes cancer — for most compounds here, no human data exist in either direction.

No concern identified

No established human cancer signal within approved use.

Regulatory status

Regulatory decisions apply to specific jurisdictions, products, formulations and indications. An approval elsewhere is not automatically an approval in your country.

Named regulators: FDA (US)

FDA-approved (Fuzeon) in combination with other antiretrovirals for treatment-experienced patients with HIV-1 with evidence of ongoing viral replication. Approval is specific to that role in combination therapy.

Evidence grade

L5Repeated human trialsHigh confidence in rating

Substantial, consistent controlled human evidence supporting a specified outcome, preferably independently replicated. Approval is reported separately.

What would change our rating?

  • Not applicable at this evidence tier.

References and sources

Source transparency

A provenance snapshot of this profile. Counts show what kinds of sources are cited, not how much scientific weight each source deserves.

Sources fully curated
Last editorial review
2026-08-23
Recently reviewed · 54 days ago
Linked curated sources
1
Sources still pending
0
External specialist reviews
0
None recorded for this profile
Regulatory / label: 1

Review provenance

Registry editorial review: Colin Jackson-White, creator and editor, who is not a doctor or clinician. External specialist review is credited only when a named reviewer has completed a review of this exact profile.

Literature-discovery and AI tools may help locate or challenge candidate evidence, but they are not counted as evidence sources here. Registry judgements are tied to the underlying papers, trial records, regulator documents and official study records.

Source hierarchy: regulatory documents and trial registries first, peer-reviewed work next, sponsor material flagged as non-independent. We never use supplier or clinic marketing as evidence, and where a verified source has not yet been curated we say so rather than inventing one.

Evidence change history

These entries record changes to our assessment of the published evidence — not changes to the compound itself.

No recorded changes yet. Baseline position set on 2026-08-23.