Not medical advice. Talk to your provider before using any peptide.
Full disclaimerPeptide Schedule Research TeamReviewed Apr 20269 Citations
B7-3326 residuesVIKLSGRELVRAQIAISGMSTWSKRSLEach bubble = one amino acid. Size = residue mass. Color = chemical class.B7-33 is a biased RXFP1 agonist that halved infarct size in mouse cardiac models without the tumor-promoting cAMP signaling of native relaxin-2. All data is preclinical. The 6-minute serum half-life and zero human trials make this a research-only compound with promising but unconfirmed anti-fibrotic potential.
100mcg · Daily
Summary: Add 2mL BAC water to your 2mg vial. Draw to 10.0 units on a U-100 syringe for a 100mcg dose. This vial will last 20 doses.
View side effects and safety warnings →
| Level | Dose / Injection | Frequency |
|---|---|---|
| Beginner | 100mcg | Daily |
| Moderate | 250mcg | Daily |
| Aggressive | 500mcg | Daily |
Your first vial of B7-33 will likely be 2 mg. Add 2 mL of bacteriostatic water and you get 1 mg/mL (1000 mcg/mL). On a standard insulin syringe, 10 units equals 100 mcg (beginner dose) and 25 units equals 250 mcg (moderate dose). If you find a 5 mg vial, adding 2 mL gives you 2.5 mg/mL; then 100 mcg is 4 units and 250 mcg is 10 units. The thing most people miss with B7-33 is the dosing frequency. The 6-minute serum half-life means once-daily injection is almost certainly not enough. The published mouse protocol used 0.25 mg/kg twice daily, 12 hours apart. If you're only injecting once a day, you're probably not getting meaningful RXFP1 engagement throughout the day. Reconstituted B7-33 degrades fast at room temperature. Keep it at 2-8 degrees C and use it within 7-10 days. Prepare only the dose you need per session. The short half-life reflects real susceptibility to proteolysis; this isn't a peptide that tolerates sloppy storage. Request an HPLC/MS Certificate of Analysis from your vendor, 98% purity minimum. Degraded B7-33 looks identical to active peptide without mass spectrometry analysis.
Dosing based on Zero human data: dose based on preclinical research — 16 published references.View all sources →
Cross-check your B7-33 reconstitution math with AI
Prices are estimates and vary by source, location, and prescription status.Full pricing breakdown →
Disclaimer: 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.
B7-33 is a biased RXFP1 agonist that halved infarct size in mouse cardiac models without the tumor-promoting cAMP signaling of native relaxin-2. All data is preclinical. The 6-minute serum half-life and zero human trials make this a research-only compound with promising but unconfirmed anti-fibrotic potential.
