Peptide Schedule
Enfuvirtide (Fuzeon)36 residuesYTSLIHSLIEESQNQQEKNEQELLELDKWASLWNWFEach bubble = one amino acid. Size = residue mass. Color = chemical class.Enfuvirtide (Fuzeon) Dosage Calculator
Enfuvirtide (brand name Fuzeon) is a first-in-class 36-amino-acid synthetic peptide that represents the first member of the HIV fusion inhibitor class of antiretroviral drugs.
90mcg · 2x Daily
Summary: Add 1.1mL BAC water to your 108mg vial. Draw to < 0.1 units on a U-100 syringe for a 90mcg dose. This vial will last 1200 doses.
Cycle Planner
Enfuvirtide (Fuzeon) Pharmacokinetics
Pharmacokinetics — Active Dose Over Time
t½ = ~3.8 hoursDisclaimer: This curve is a simplified first-order exponential decay model. Actual pharmacokinetics vary based on injection site, individual metabolism, body composition, and other factors. Half-life values are approximate and based on available preclinical and clinical literature. Many research peptides lack formal human pharmacokinetic studies. This is for educational purposes only — not medical advice.
Enfuvirtide (Fuzeon) Dosing Protocol
| Level | Dose / Injection | Frequency |
|---|---|---|
| Beginner | 90mg | 2x Daily |
| Moderate | 90mg | 2x Daily |
| Aggressive | 90mg | 2x Daily |
Note: Enfuvirtide is the first FDA-approved HIV fusion inhibitor, a 36-amino-acid synthetic peptide derived from the HR2 region of HIV-1 gp41. It is administered as 90 mg twice daily via subcutaneous injection as part of combination antiretroviral therapy (cART). Each vial contains 108 mg of lyophilized powder and is reconstituted with 1.1 mL of Sterile Water for Injection (SWFI) to deliver approximately 90 mg/mL. Enfuvirtide is reserved for treatment-experienced patients with ongoing HIV-1 replication despite existing antiretroviral regimens. Rotate injection sites between upper arm, anterior thigh, and abdomen to minimize injection site reactions, which occur in nearly all patients.
About Enfuvirtide (Fuzeon)
Enfuvirtide (brand name Fuzeon) is a first-in-class 36-amino-acid synthetic peptide that represents the first member of the HIV fusion inhibitor class of antiretroviral drugs. Approved by the FDA on March 13, 2003, enfuvirtide works by a completely novel mechanism compared to other antiretrovirals — it blocks HIV-1 from physically fusing with and entering host CD4+ T-cells. The peptide sequence is derived from the heptad repeat 2 (HR2) domain of the HIV-1 transmembrane glycoprotein gp41, enabling it to competitively bind to the HR1 domain and prevent the conformational rearrangement essential for viral-cell membrane fusion. In pivotal Phase III clinical trials (TORO-1 and TORO-2), enfuvirtide plus an optimized background regimen produced significantly greater viral load reductions (mean -1.48 log10 copies/mL at 48 weeks) compared to the optimized background regimen alone (-0.63 log10), along with superior CD4+ T-cell count recovery (+91 vs. +45 cells/mm3). Enfuvirtide is exclusively indicated for treatment-experienced adults and pediatric patients (weighing at least 11 kg) who have evidence of HIV-1 replication despite ongoing antiretroviral therapy. Because it targets viral entry rather than intracellular replication machinery, enfuvirtide retains activity against strains resistant to NRTIs, NNRTIs, and protease inhibitors. The drug has a favorable pharmacokinetic profile with 84.3% subcutaneous bioavailability and a short elimination half-life of approximately 3.8 hours, necessitating twice-daily dosing. Although injection site reactions are nearly universal, enfuvirtide remains a critical salvage therapy option for patients with multi-drug-resistant HIV-1 infection.