GLP-3
GLP3Triple-agonist incretin research peptide.
Also known as: LY3437943, Triple-G
Overview
GLP-3 is a triple-receptor agonist targeting GIP, GLP-1, and glucagon receptors, studied in advanced metabolic and energy-balance research.
Phase II research reported the largest weight reductions observed for an incretin agent to date — up to ~24% mean body-weight change at the highest amounts studied over 48 weeks — alongside improvements in glycemic and hepatic-fat markers. Triple-receptor activation is hypothesized to add glucagon-driven energy expenditure on top of GLP-1/GIP appetite and insulin effects.
Simultaneously activates GIP, GLP-1, and glucagon receptors, combining insulin response, appetite modulation, and energy expenditure.
Molecular information
C20 fatty-diacid-conjugated 39-residue peptide backbone (Lilly LY3437943).C20 diacid conjugation extends albumin binding for once-weekly kinetics.
Pharmacokinetics
Illustrative relative-concentration model derived from published pharmacokinetic research. Curve is normalized and provided for educational comparison only — not a dosing schedule.
Research applications
- Triple-incretin metabolic research
- Energy-balance studies
- Glucose- and lipid-metabolism investigations
Research protocols
Protocols summarized from published research models. Provided for scientific reference only — not dosing guidance for human use.
Observed effects timeline
Aggregated observations reported across research literature. Timing and magnitude vary by model and are not a guarantee of outcome.
Week 1–2
Initial appetite modulation and mild GI adaptation reported as triple-receptor signaling begins.
Week 4–8
Steady reductions in food intake and early weight change (≈2–10%) reported in study cohorts.
Week 16–24
Substantial weight change (≈15–22%) with improved glucose and hepatic-fat markers reported.
Week 24–48
Maximum observed effect (≈20–24%) with continued metabolic improvements reported.
Research compatibility
Describes how compounds are studied alongside one another in the literature. Not a recommendation to co-administer.
Tirzepatide
Stacking two multi-receptor incretin agonists compounds appetite suppression and GI burden with unpredictable hormonal overlap — studied as alternatives, never together.
GLP-1
Overlapping incretin signaling is redundant — the two are evaluated as separate research arms, not in combination.
Other GLP-1 agonists
Adding a separate GLP-1 agonist duplicates receptor activation already covered by the triple agonist, raising the risk of excessive glucose-lowering and side effects.
Cagrilintide
Both drive significant gastric and nausea effects; the amylin + triple-agonist mechanisms differ but the additive GI load is substantial and only advisable under close research supervision.
Oral contraceptives
Delayed gastric emptying can blunt absorption — separate oral contraceptive dosing by roughly an hour ahead of injection in study designs.
Insulin
Improved glucose control can sharply lower insulin requirements — track blood glucose closely and adjust accordingly in metabolic studies.
Warfarin
Rapid weight change can shift anticoagulation needs — INR warrants more frequent monitoring during active research.
Metformin
Complementary glucose-lowering through distinct mechanisms; co-administration showed no significant interaction in trial cohorts.
SGLT2 inhibitors
Trial participants on SGLT2 inhibitors showed no safety signals — the glucose-handling mechanisms are complementary.
MOTS-c
Distinct mitochondrial-metabolism pathway; studied alongside incretin agents in metabolic-research contexts.
BPC-157
Separate therapeutic targets — tissue-repair growth-factor signaling versus metabolic hormone receptors; may offer GI-protective benefit during use.
NAD+
Different cellular systems — hormone-receptor signaling versus cellular-energy and DNA-repair pathways; may support metabolic adaptation during weight change.
How to reconstitute
Use bacteriostatic water only; avoid saline, which may cause cloudiness. Refrigerate reconstituted solution and use within ~28 days (often 1–3 months if it stays clear).
- 1Allow the lyophilized vial to reach room temperature (15–20 minutes).
- 2Swab the vial stopper with alcohol and let it air dry.
- 3Add the calculated bacteriostatic water slowly down the vial wall to minimize foaming.
- 4Swirl gently — do not shake — until fully dissolved into a clear, colorless solution.
- 5Store refrigerated at 2–8 °C and protect from light.
Quality indicators
Uniform white powder
Lyophilized peptide should appear as a white to off-white cake with no discoloration.
Clear reconstituted solution
Properly reconstituted material forms a clear, colorless, particle-free solution.
Cold-chain integrity
Reconstituted solution requires consistent 2–8 °C storage.
Slight clumping
Small clumps that dissolve completely with gentle swirling are acceptable — shipping can cause minor compaction.
Collapsed or melted appearance
Powder that looks collapsed, melted, or stuck to the vial walls may have been exposed to heat in transit.
Cloudy after reconstitution
Persistent cloudiness, particles, or precipitate after gentle mixing can indicate a degraded or contaminated peptide.
Reported observations & safety
Safety signals reported in the research literature. Compiled for scientific awareness — not medical advice.
- Gastrointestinal effects (nausea, reduced appetite) are the most commonly reported signals in studies and are dose-dependent.
- Heart-rate increases have been noted in some research cohorts.
- Rapid changes warrant conservative escalation in study designs.
References & further reading
Retatrutide Phase 2 Obesity Trial (NEJM, 2023)
Randomized Phase 2 trial of the GIP/GLP-1/glucagon triple agonist reporting dose-dependent body-weight reductions over 48 weeks.
View studyTriple-hormone receptor pharmacology review
Overview of how simultaneous GIP, GLP-1, and glucagon activation differs from dual and single agonists in metabolic research.
Topics
This entry is provided for educational and informational purposes only. It is not medical advice, a dosing protocol, or a claim of therapeutic benefit. Research compounds are supplied strictly for laboratory and research use — not for human or veterinary consumption.
Large body of preclinical and clinical literature.
GLP-3 is stocked as a research-grade compound, ≥99% by HPLC, third-party verified.
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