Published Clinical Trial Protocols: Documented Parameters for Semaglutide, Tirzepatide, Retatrutide, BPC-157, and More

Why Dosing Schedules Matter in Research

One of the most common questions in peptide research communities is: what dosing schedules did the clinical trials actually use, and how do they compare to what researchers are using in practice? This article compiles the published trial data for the most researched peptides in our catalog — GLP-1 agonists, BPC-157, TB-500, GHK-CU, and NAD+ — along with the pharmacokinetic rationale behind each protocol.

All information below reflects published research protocols. This is for research and educational purposes only — not medical advice or dosing guidance for human use.

GLP-1 Agonists: Weekly Subcutaneous Protocol

All three major GLP-1/GIP/glucagon agonists share a weekly dosing schedule in published trials, driven by their extended half-lives achieved through albumin binding and fatty acid conjugation. The general research protocol follows a dose-escalation pattern to allow GI adaptation before reaching target dose.

Semaglutide — STEP Trial Protocol

Week	Weekly Dose	Notes
1–4	0.25mg	Initiation phase — GI adaptation
5–8	0.5mg	First escalation
9–12	1.0mg	Second escalation
13–16	1.7mg	Third escalation
17+	2.4mg	Maintenance dose (STEP 1 target)

Half-life: ~7 days | Steady state: 4–5 weeks at maintenance dose | Trial duration: 68 weeks (STEP 1)

Tirzepatide — SURMOUNT Trial Protocol

Week	Weekly Dose	Notes
1–4	2.5mg	Initiation — not a therapeutic dose
5–8	5mg	First therapeutic level
9–12	7.5mg	Escalation
13–16	10mg	Escalation
17–20	12.5mg	Escalation
21+	15mg	Maximum maintenance dose

Half-life: ~5 days | Mean weight reduction at 72 weeks: 20.9% (15mg cohort)

Retatrutide — Phase II Protocol (NEJM 2023)

Cohort	Weekly Dose	48-Week Result
Low	1mg → 4mg	~8.7% mean weight reduction
Mid	2mg → 8mg	~17.1% mean weight reduction
High	4mg → 12mg	~24.2% mean weight reduction

Half-life: ~6 days | Escalation: 4-week intervals | Note: Phase II used fixed cohort doses, not a single universal escalation schedule

BPC-157 — Research Protocol Overview

BPC-157 has a significantly shorter half-life than GLP-1 agonists (~4–6 hours for systemic effects), which drives a different dosing frequency in research models. Preclinical studies have used both systemic and localized administration depending on the research target.

Parameter	Preclinical Research Range
Frequency	Once or twice daily in most models
Dose range studied	1–10 mcg/kg bodyweight (rodent models)
Protocol duration	7–30 days in most injury/repair studies
Administration route	Subcutaneous, intraperitoneal, or oral (oral active in gastric studies)

Research has examined BPC-157 in tendon, ligament, nerve, muscle, and GI injury models. The twice-daily frequency in most protocols reflects the short half-life and the goal of maintaining consistent systemic levels during active tissue remodeling phases.

TB-500 — Loading and Maintenance Protocol

TB-500 research protocols have used a two-phase approach: a loading phase with higher frequency dosing to rapidly build tissue levels, followed by a reduced-frequency maintenance phase.

Phase	Frequency	Duration
Loading	Twice weekly	4–6 weeks
Maintenance	Once weekly or biweekly	Ongoing per protocol

GHK-CU — Daily Topical and Systemic Research

GHK-CU research has explored both topical and systemic administration. Skin and collagen research has primarily used topical formulations; systemic anti-aging and tissue repair studies have used subcutaneous administration.

Route	Frequency in Research	Notes
Topical	Once or twice daily	Skin/collagen studies
Subcutaneous	Daily	Systemic anti-aging and repair studies

NAD+ — Frequency and Administration

NAD+ precursor research has examined multiple administration routes with different frequency implications:

• Subcutaneous NAD+: Daily or every-other-day in most longevity and neuroprotection research models
• NMN/NR oral precursors: Daily in human clinical studies — slower onset but sustained levels
• IV NAD+ (clinical settings): 3–5 day loading protocols, then maintenance — not applicable to standard research contexts

Key Principles Across All Protocols

• Half-life drives frequency: Long half-life (GLP-1s) = weekly dosing. Short half-life (BPC-157) = daily or twice daily
• Escalation reduces side effects: Starting low and increasing gradually allows physiological adaptation — standard practice across all GLP-1 trial designs
• Steady state matters: Most GLP-1 agonists require 4–5 weeks at a stable dose to reach steady state — results measured before this point underestimate the compound's effect
• Washout periods: GLP-1 agonists require 5 half-lives to clear — ~5 weeks for semaglutide, ~4 weeks for tirzepatide and retatrutide

All information in this article reflects published research protocols from peer-reviewed trials. All products sold by My Freedom Peptides are for research use only. Not intended for human consumption, medical treatment, or diagnostic use. This article does not constitute medical advice or dosing guidance.

For research use only. Not intended for human consumption.