Methodology
Everything on this site is computed by the same open, tested formulas — documented here with worked examples and sources, so any number can be checked by hand.
Reconstitution & syringe math
- concentration (mg/mL) = peptide in vial (mg) ÷ BAC water (mL)
- draw volume (mL) = dose ÷ concentration
- U-100 units = draw volume × 100 (U-50: ×50 · U-30: ×30)
- doses per vial = vial contents ÷ dose (floored)
Worked example: 5 mg + 2 mL = 2.5 mg/mL; a 250 mcg dose = 0.25 ÷ 2.5 = 0.1 mL = 10 units on a U-100 syringe; 5 mg ÷ 250 mcg = 20 doses.
Half-life & decay curves
Curves use first-order exponential decay: level(t) = dose × 0.5^(t ÷ half-life). "~97% cleared" = five half-lives (0.5⁵ ≈ 3.1% remaining). These are population estimates from the cited literature — individual pharmacokinetics vary with route, formulation, and physiology.
Sources
| Compound | Half-life used | Primary source |
|---|---|---|
| Semaglutide | ≈ 7 days | PubMed 29915923 (semaglutide clinical pharmacokinetics) |
| Tirzepatide | ≈ 5 days | FDA label: Mounjaro (tirzepatide) prescribing information |
| BPC-157 | ≈ 4–6 h | PMC9794587 (BPC-157 pharmacokinetic review; PK-PD disconnect noted) |
| TB-500 | ≈ 2–3 days | Thymosin β4 pharmacokinetic literature (see monograph) |
| Ipamorelin | ≈ 2 h | Ipamorelin GH-secretagogue PK studies (see monograph) |
| CJC-1295 | ≈ 8 days | CJC-1295 (DAC) half-life studies (see monograph; no-DAC differs sharply) |
| Testosterone Cypionate | ≈ 8 days | Testosterone cypionate PK literature (cited range 4–10 days; see monograph) |
| Anastrozole | ≈ 46 h | FDA label: Arimidex (anastrozole) prescribing information |
| HCG | ≈ 33 h | hCG pharmacokinetic literature (see monograph) |
| Retatrutide | ≈ 6 days | Retatrutide phase-2 pharmacokinetics (Jastreboff, NEJM 2023; half-life ≈6 days) |
| GHK-Cu | ≈ 30 min | Pickart & Margolina (Int J Mol Sci 2018); plasma half-life <30 min |
| PT-141 | ≈ 2.7 h | FDA VYLEESI (bremelanotide) label, NDA 210557 (2019); plasma half-life ≈ 2.7 h |
| Cagrilintide | ≈ 7–8 days | Cagrilintide review (Cardiology in Review 2023, PMID 36883831); half-life ≈ 7–8 days |
| GHRP-6 | ≈ 15–30 min | Bowers (J Clin Endocrinol Metab 1990, PMID 2108187); cleared within ~1 h |
| GHRP-2 | ≈ 30 min | GHRP-2 / pralmorelin PK (Asakura 2010, PMID 20662346); GH peak ~60 min then cleared |
| Thymosin Alpha-1 | ≈ 2 h | Thymosin α1 SubQ pharmacokinetics (PMID 10027483); elimination half-life ≈ 2 h |
| Liraglutide | ≈ 13 h | FDA Saxenda label (NDA 206321); plasma half-life ≈ 13 h (once-daily) |
| Survodutide | ≈ 6 days | Survodutide (GLP-1/glucagon) PK (Zimmermann 2022, PMC9679702); once-weekly |
| Mazdutide | ≈ 8 days | Mazdutide GLORY-2 (JAMA 2026, PMID 42251595); once-weekly dosing |
| Gonadorelin | ≈ 10–40 min | GnRH pharmacology (Belchetz 1978, PMID 100883); terminal half-life 10–40 min |
| SS-31 (Elamipretide) | ≈ 4 h | Elamipretide (SS-31) SubQ PK ≈ 4 h; FDA accelerated approval 2025 (Barth syndrome) |
| IGF-1 LR3 | ≈ 20–30 h | IGF-1 LR3 analog characterization (Francis 1992, PMID 1378742); ≈20–30 h (animal-derived, not human-verified) |
Corrections policy
Values are versioned. When a better source changes a number, the page updates and the change is recorded — never silently. Found an error? We want it: corrections are credited (with consent).
What we will not do
- Recommend doses, protocols, or changes to either — for anyone, paid or free.
- Answer sourcing questions or link to vendors — anywhere, ever.
- Make medical claims. These are research and educational references.
Who builds this
The Zyra Labs team — the same engine that powers these pages runs our protocol-tracking app. A medical reviewer's byline will accompany compound pages as the review program comes online; until then, every value traces to the cited primary literature.
Zyra Labs is a research and educational utility. Nothing on this page is medical advice, a dosing recommendation, or an endorsement of any compound. We never sell or source compounds and refuse sourcing questions. Consult a qualified clinician for decisions about your health.