Frequency Protocol Information
How often, by what route, at what doses and for how long each peptide in our library was given in published human research, side by side, with a link to every source.
| Peptide | Regulatory status | Route in studies | Frequency in studies | Dose range studied | Duration | Source |
|---|---|---|---|---|---|---|
| Semaglutide | FDA-approved Rx (Wegovy) | Subcutaneous injection | Once weekly | 0.5 or 1.0 mg (SUSTAIN-6); 2.4 mg (STEP 1, SELECT). FDA label (injection): 0.25 mg starting dose, maintenance 1.7 or 2.4 mg, label maximum 7.2 mg | 68 weeks (STEP 1); 104 weeks (SUSTAIN-6); mean 34.2 months (SELECT) | STEP 1, NEJM 2021 SUSTAIN-6, NEJM 2016 SELECT, NEJM 2023 Wegovy label, DailyMed |
| Tirzepatide | FDA-approved Rx (Mounjaro, Zepbound) | Subcutaneous injection | Once weekly | 5, 10 or 15 mg (SURMOUNT-1, SURPASS-2). FDA label (Zepbound): 2.5 mg starting dose for 4 weeks, 2.5 mg steps, maintenance 5, 10 or 15 mg, label maximum 15 mg | 72 weeks (SURMOUNT-1); 40 weeks (SURPASS-2) | SURMOUNT-1, NEJM 2022 SURPASS-2, NEJM 2021 Zepbound label, DailyMed |
| Retatrutide | Investigational. Not approved anywhere; no approved dose | Subcutaneous injection | Once weekly | 1 to 12 mg in the obesity trial (some arms started at 2 or 4 mg); 0.5 to 12 mg in the type 2 diabetes trial | 48 weeks (obesity, phase 2); 36 weeks (type 2 diabetes, phase 2) | Phase 2 obesity, NEJM 2023 Phase 2 T2D, Lancet 2023 |
| PT-141 (bremelanotide) | FDA-approved Rx (Vyleesi) for one indication: acquired, generalized HSDD in premenopausal women | Subcutaneous injection | As needed. FDA label: no more than one dose within 24 hours; more than 8 doses per month not recommended | 1.75 mg per dose (RECONNECT 301 and 302, and FDA label) | 24 weeks (RECONNECT) | RECONNECT, Obstet Gynecol 2019 Vyleesi label, DailyMed |
| BPC-157 | Not FDA-approved for any use | Human reports only: bladder-wall injection (n=12); IV infusion (n=2); intra-articular injection (n=16) | No established human dosing protocol in published trials. Human reports describe single procedures or 2 infusion days; no repeated schedule has been studied | 10 mg total, single procedure (n=12); 10 mg then 20 mg on consecutive days (n=2); not reported in the abstract (n=16) | Single procedure; 2 days; follow-up 6 to 12 months (retrospective) | Lee 2024 Lee 2025 Lee 2021 Systematic review 2026 |
| GHK-Cu | Not FDA-approved. Injectable form nominated for compounding, then withdrawn | Topical skin-care products only (one small randomized study). No published human study of injection | No established human dosing protocol in published trials. Application frequency not stated in the abstract | Concentration not stated in the abstract. No injected dose has been studied in people | 12 weeks (n=13 completers) | Miller 2006 Pickart 2018 review |
Notes by peptide
Semaglutide
Three large randomized trials (STEP 1, SUSTAIN-6, SELECT) all gave semaglutide by once-weekly subcutaneous injection. The current Wegovy label also covers an oral tablet taken once daily, which is not shown in the table. For an approved drug, the dose is set by the prescriber under the FDA label.
Tirzepatide
SURMOUNT-1 (obesity) and SURPASS-2 (type 2 diabetes) tested three once-weekly maintenance doses. The Zepbound label describes 2.5 mg as a starting dose only, not a maintenance dose.
Retatrutide
Both published trials are phase 2. Phase 3 results and an FDA decision are still pending, so there is no approved dose. Any retatrutide sold online is unapproved.
PT-141 (bremelanotide)
The phase 3 RECONNECT trials studied a single fixed dose given as needed, in premenopausal women with HSDD. That is the only population in which the FDA approved it. The label's limits on how often it is given come from blood-pressure effects seen in studies.
BPC-157
The human record is three small, uncontrolled reports from one clinic group, with 30 participants in total. A 2026 systematic review concluded that BPC-157 should not be used clinically outside regulated, high-quality trials. Most BPC-157 research is in animals, and we deliberately do not convert animal doses into human doses.
GHK-Cu
The only randomized human study we verified used topical skin-care products after laser resurfacing and found no objective benefit over the control regimen. No human safety or dosing data exist for injected GHK-Cu in the sources we reviewed.