Side-by-side · Research reference

RetatrutidevsTB-500

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 2Reviewed10/41 cited

BPhase 2Reviewed8/46 cited

Retatrutide

Triple-receptor agonist · Phase 3

1–12 mgWeekly doseJastreboff 2023

24.2%Body-weight ↓Jastreboff 2023

~6 daysHalf-life (est)

SQ · Abdomen · Once weekly

TB-500

Thymosin β4 fragment · Healing

2 mgPer doseGoldstein 2012

Phase 2Evidence levelGoldstein 2012

~2 hrHalf-life

SQ or IM · Multiple sites · 2–3×/week

01Mechanism of Action

Parameter

Retatrutide

TB-500

Primary target

GLP-1R + GIPR + Glucagon receptor (triple agonism)Jastreboff 2023

G-actin (sequestering) + cell-surface integrinsGoldstein 2012

Pathway

Triple-receptor activation → ↑insulin (GLP-1+GIP), ↓gastric emptying, ↑lipid handling, ↑energy expenditure (glucagon component)Jastreboff 2023

Actin remodelling → cell migration; integrin-linked signaling → angiogenesis; anti-inflammatory cytokine modulationGoldstein 2012 Malinda 1999

Downstream effect

Maximal weight loss across class. Glucagon component drives lipolysis and energy expenditure beyond GLP-1+GIP aloneJastreboff 2023

Accelerated wound healing, endothelial migration, hair follicle regeneration, cardiac repair (preclinical)Goldstein 2012

Feedback intact?

—

Endogenous protein at baseline; supplementation amplifies

Origin

Synthetic peptide engineered for balanced affinity at three incretin / glucagon receptorsJastreboff 2023

17-AA active fragment of endogenous 43-AA thymosin β4 (TMSB4X gene)Goldstein 2012

Antibody development

—

02Dosage Protocols

Parameter

Retatrutide

TB-500

Standard dose

12 mg / week (max efficacy)Jastreboff 2023

Phase 2 trial dose. Phase 3 dosing TBD.

2 mg per injectionGoldstein 2012

Anecdotal community range; clinical Phase 2 trials used 70–840 mcg/kg IV.

Frequency

Once weekly

2× per week (loading); then 1× per week (maintenance)

Titration schedule

2 mg → 4 mg → 8 mg → 12 mg over 16 weeks

—

Evidence basis

Phase 2 trial; Phase 3 ongoingJastreboff 2023

Animal-strong + Phase 2 dermal/ocular trialsGoldstein 2012

Duration

Indefinite for chronic indication (presumed)

4–8 weeks loading; longer maintenance for chronic injury

Reconstitution

Investigational; not commercially available

Bacteriostatic water, 1–2 mL per 5 mg vial

Timing

Any time of day

Evening or pre-rest preferred (anecdotal)

Half-life

~6 days (estimated from class)

~2 hours (estimated; tissue uptake longer)

Lower / starter dose

—

1 mg per injection

04Side Effects & Safety

Parameter

Retatrutide

TB-500

GI symptoms

Nausea, vomiting, diarrhea (very common, dose-dependent)Jastreboff 2023

Rare nausea (anecdotal)

Heart rate

↑ resting HR (3–7 bpm at 12 mg)Jastreboff 2023

—

Glucose handling

Glycemic improvement; rare hyperglycemia from glucagon component

—

Pancreatitis risk

Class warning

—

Thyroid C-cell tumours

Class warning (presumed)

—

Pregnancy / OB

Avoid (insufficient data)

Avoid

Injection site reaction

—

Mild erythema, transient pain

Cancer risk

—

Theoretical via angiogenesis pathway

Lethargy / fatigue

—

Reported anecdotally during loading phase

Antibody formation

—

No data (no long-term human trials)

Long-term safety

—

Unknown beyond Phase 2

Absolute Contraindications

Retatrutide

·MTC personal or family history (presumed class effect)
·Pregnancy / breastfeeding

TB-500

·Active malignancy (theoretical angiogenesis concern)
·Pregnancy / breastfeeding

Relative Contraindications

Retatrutide

·Severe gastroparesis
·History of pancreatitis
·Severe cardiovascular disease (HR signal)

TB-500

·Cancer history
·Concurrent VEGF inhibitor therapy

05Administration Protocol

Parameter

Retatrutide

TB-500

1. Reconstitution

Investigational peptide. Research vials reconstituted with bacteriostatic water per label.

Add 1–2 mL bacteriostatic water to 5 mg vial → 2.5–5 mg/mL. Roll gently.

2. Injection site

SQ — abdomen, thigh, or upper arm. Rotate weekly.

SQ near injury site (preferred), or systemic SQ (abdomen). Rotate sites.

3. Timing

Once weekly, same day.

Evening or pre-sleep is most common anecdotal timing.

4. Storage

Refrigerate 2–8 °C. Light-protected.

Lyophilised: room temp, light-protected. Reconstituted: refrigerate, ≤30 days.

5. Needle

27–31G, 4–8 mm insulin syringe.

06Stack Synergy

Retatrutide

— no documented stacks

TB-500

+ BPC-157

Strong

View BPC-157 →

TB-500 and BPC-157 cover complementary halves of tissue repair: BPC-157 upregulates VEGFR2-driven angiogenesis and fibroblast outgrowth; TB-500 sequesters G-actin to enable endothelial / epithelial migration. The anecdotal canonical "healing stack" — pairs especially well for tendon and ligament injuries.

TB-500: 2 mg SQ · 2× per week
BPC-157: 250–500 mcg SQ · daily
Primary benefit: Combined angiogenesis + cell migration for tendon/ligament/muscle repair