As of September 2026, the FDA and the EMA have approved enfuvirtide for HIV in people who have already had other treatment. Two Phase 3 trials, TORO 1 and TORO 2, were the basis for approving Fuzeon, the branded product. If a vial sold as enfuvirtide reached you outside a pharmacy, those trials did not test it, and nothing on the outside shows you what it holds.
Get an email when the enfuvirtide record changes.
What is enfuvirtide?
Enfuvirtide is a lab-made chain of 36 amino acids that stops HIV from fusing with and entering human immune cells. It was developed at Duke University in the 1990s by researchers who founded Trimeris and then partnered with Hoffmann-La Roche. The FDA approved it in March 2003 as the first HIV fusion inhibitor, a medicine that blocks that step.
Does enfuvirtide work?
For HIV in people who have already had other treatment, the FDA reviewed the trials and approved it. The EMA approved it for an equivalent use.
What we found. 2 completed randomized trials counted on the record. 2 study rows listed below. The first names two trials, TORO 1 and TORO 2. The record does not say which of the listed studies were randomized.
| Study | Tested in | Status | What it shows |
|---|---|---|---|
| TORO 1 and TORO 2, the main Phase 3 trials | People | Completed. The basis for approval | Adding enfuvirtide to an optimized background of other HIV medicines gave a bigger fall in the amount of virus |
| T-20 resistance study, with the medicine used on its own | People | Completed | Resistance mutations emerged quickly when it was used without a fully active background treatment |
Is enfuvirtide safe?
The record describes an extensive human safety record from more than two decades of clinical use. The key concerns it names include very common reactions where the medicine is given and a modest risk of bacterial pneumonia in some studies. Recent real-world data on its use as a first treatment are sparse. All of this is about Fuzeon, the approved product. A vial from any other source is a separate question, and the vial section takes it up.
Is enfuvirtide legal?
- United States
- Approved by the FDA in March 2003 as Fuzeon, for HIV in people who have already had other treatment.
- European Union
- Approved by the EMA for an equivalent use.
- Sport
- Not named on WADA's list. That is not clearance.
Not medical advice. Approval and sport status as of . Medical disclaimer
What is in a vial sold as enfuvirtide?
The two TORO trials were the basis for approving Fuzeon. This record holds no sign that enfuvirtide is sold outside pharmacies. If a vial reached you another way, those trials did not test it, and the checklist lists what to ask the seller.
What don't we know?
- What enfuvirtide does as a first treatment today. Recent real-world data on that use are sparse.
- Whether a reformulated version will return to active development. New data would matter mainly then.
- What is in a vial sold as enfuvirtide that never passed through a pharmacy.
The other side
Enfuvirtide comes with a prescription and HIV care, and the record describes more than two decades of clinical use. Newer options that are easier to take have cut its use. It remains an approved option for hard-to-treat cases.
What would change this record?
- A reformulated version going back into active development. The record says new data would matter mainly in that case.
Three questions to ask next
- What does 'research use only' actually mean?
- How can you tell if a peptide vendor is legitimate?
- How do you read a certificate of analysis?
Ask better questions.
More questions about enfuvirtide
What is enfuvirtide used for?
- HIV, in people who have already had other treatment. The record says it is used alongside other HIV medicines.
Is enfuvirtide the same as Fuzeon?
- Fuzeon is the brand name for enfuvirtide. The record also lists the name T-20.
Is enfuvirtide still approved?
- Yes. The record says its use has declined because newer, easier options exist, and that it remains an approved option for hard-to-treat cases.
Can HIV become resistant to enfuvirtide?
- Yes. One completed study documented resistance mutations emerging quickly when it was used without a fully active background treatment.
Is enfuvirtide banned in sport?
- It is not named on WADA's list. The record gives no sport source for that. If you compete, check the current List.
Record checked on . Each source shows the date it was checked.
In the same group
- Icatibant (Firazyr)Grade A4+ completed randomized trials
- Lanreotide (Somatuline Depot)Grade A6+ completed randomized trials
- Leuprolide acetate (Lupron)Grade A6+ completed randomized trials
- Linaclotide (Linzess)Grade A5+ completed randomized trials
- Octreotide (Sandostatin)Grade A10+ completed randomized trials
- Plecanatide (Trulance)Grade A4+ completed randomized trials