Research Library / Metabolic / Retatrutide
Metabolic researchRetatrutide (LY3437943)
LY3437943 · Triple agonist
An investigational once-weekly triple receptor agonist with newly published phase 3 obesity data; it remains unavailable as an approved medicine. The listed community example (conservative community titration) describes 0.5–1 mg per administration, once weekly, via subcutaneous; this is not a validated dosing recommendation. An illustrative 10 mg vial at an assumed 2 mL final volume yields 5 mg/mL; diluent compatibility remains product-specific. For research and education only, not personal medical guidance.
Quick Reference
- Example vial
- 10mg
- Assumed final volume
- 2mL · not an amount to add
- Concentration
- 5mg/mL · conditional arithmetic
- One U-100 marking
- 50mcg in 0.01 mL
Hypothetical vial math does not reproduce a study formulation or verify a diluent, sterility or storage period.
Research schedules
Once weekly · subcutaneous · 80 weeks
| Weeks | mg/week | mL* | U-100* |
|---|---|---|---|
| 1–4 | 2 | 0.4 | 40 |
| 5–8 | 4 | 0.8 | 80 |
| 9–12 | 6 | 1.2 | 120 |
| 13–16 | 9 | 1.8 | 180 |
| 17–80 | 12 | 2.4 | 240 |
One assigned target arm. Other trial groups used lower targets. *Conditional vial conversions; over 100 markings exceeds a 1 mL syringe.
Reported schedule context
- Range
- 0.5–4 mg/week commonly reported; phase 3 studied targets to 12 mg
- Frequency
- Weekly
- Route
- Subcutaneous
- Reported half-life
- ~6 days
- Reported cycle
- Community cycling unvalidated; phase 3 treatment lasted 80 weeks
Community ranges remain anecdotal. The separate trial-derived rows show the published 2 mg initiation and 4-week escalation used in TRIUMPH-2.
Cross-reference reviewed October 2026. Half-life and cycles retain this source context.| Context / phase | Amount | Schedule total | Frequency | Timing | Route | Evidence |
|---|---|---|---|---|---|---|
| Conservative community titration | 0.5–1 mg | 0.5–1 mg/week | Once weekly | Same day each week | Subcutaneous | Community-reported |
| Common community range | 2–4 mg | 2–4 mg/week | Once weekly | Same day each week | Subcutaneous | Community-reported |
Repeated community reports do not establish identity, safety, effectiveness or an appropriate exposure. Component schedules do not validate a same-vial blend.
Vial calculator
Linked to Quick Reference and compatible supply calculations.
Read the needle-side edge of the black stopper. Liquid tint is illustrative.
Scale illustration · one U-100 marking = 0.01 mL.
Arithmetic yield at this example amount
10 example portions per vial
10 full amounts; 0 mg remaining. Yield is not a storage or reuse period.
See the calculation
Concentration = vial content ÷ final volume. Volume = example amount ÷ concentration. U-100 markings = mL × 100.
Original example & formulation context
1 mg · 5 mg/mL · 0.2 mL · 20 units
Clinical retatrutide trial products are not equivalent to an unspecified research powder. Community accounts describe cloudiness and experiments with BAC water, PBS and acidified solutions. The calculation assumes the stated final solution volume, which may differ from liquid added. It does not verify dissolution, solvent compatibility, sterility, chemical stability or storage. See the source-linked preparation notes below.
Supplies & vial yield
Selected study arm and vial example. These minimum totals ignore losses and product-specific discard limits.
Peptide vials
| Horizon | Total | Vials* |
|---|---|---|
| 12 weeks | 48 mg | 5 × 10 mg |
| 24 weeks | 180 mg | 18 × 10 mg |
Liquid planning
| Horizon | Assumed final solution |
|---|---|
| 12 weeks | 10 mL |
| 24 weeks | 36 mL |
Diluent identity and bottle quantities are not established.
U-100 capacity
| Horizon | Weekly events | Over 1 mL |
|---|---|---|
| 12 weeks | 12 | 4 |
| 24 weeks | 24 | 16 |
No automatic syringe quantity or split-dose method is assigned.
Planning limits
*Vials are total nominal mass divided by vial content, rounded up. These horizons are not recommended cycles. Final solution volume is not a verified amount of liquid to add.
*Conditional mass and final-volume arithmetic. No stability, sterility, safe reuse period or verified diluent quantity is established. Cleansing materials, sterile supplies, labels and sharps disposal follow the actual research procedure.
Protocol overview & research context
- Identity
- Retatrutide · LY3437943 · Triple agonist
- Evidence / status
- Phase III. Investigational — not FDA approved; U.S. submission planned for 2027
- Clinical route, frequency & duration
TRIUMPH-1 phase 3 trial: 4, 9 or 12 mg target doses · subcutaneous · once weekly · 80 weeks · stepwise escalation
TRIUMPH-2 phase 3 trial: 2 mg initiation; increased every 4 weeks through 4 and 6 mg, with a 9 mg step for the 12 mg arm · subcutaneous · once weekly · 80 weeks
TRIUMPH-1-OSA and TRIUMPH-2-OSA: 4, 9 or 12 mg target doses · subcutaneous · once weekly · 80 weeks; primary apnea–hypopnea endpoint assessed with 9 and 12 mg
- Community purpose
- Appetite suppression, weight management, and broader metabolic research.
- Reported timing / route
- Weekly · Subcutaneous. Schedule-specific timing remains in the Community tab.
- Reported half-life
- ~6 days · community-reference context, not a shelf life.
- Reported cycle
- Community cycling unvalidated; phase 3 treatment lasted 80 weeks. Planning horizons do not establish a validated cycle.
Loading, titration and maintenance
A separate loading phase is not identified in this library entry. Titration, maintenance and stopping rules depend on the specific product or study; a listed range is not automatically an escalation plan.
Reconstitution & formulation
Clinical retatrutide trial products are not equivalent to an unspecified research powder. Community accounts describe cloudiness and experiments with BAC water, PBS and acidified solutions.
Other vehicles and approaches discussed
These are conflicting, uncontrolled reports. They do not establish a universal buffer, safe mixing ratio, cause of cloudiness or solution shelf life.
- Evidence context
- Product / laboratory / report distinctions apply
- Cloudiness / gel signal
- Community clouding reports; generic formulation unresolved
- Product details to verify
- Verify the exact product, sequence/salt form, buffer and excipients, concentration, route, container and product-specific storage instructions.
Sources apply to the named product, laboratory method or report only. Laboratory solvents and community repetition do not establish an injectable preparation, sterility, chemical stability or a beyond-use period. No solvent-mixing or salvage recipe is provided.
Preparation references reviewed October 20, 2026.
Preparation documentation checklist
- Confirm identity, nominal content, salt form, buffer and excipients.
- Verify the actual product's diluent, amount to add and intended method.
- Calculate concentration from final solution volume, and cross-check units.
- Record lot, concentration, diluent, preparation date, storage and discard instructions.
This checklist does not replace a validated preparation procedure.
Storage, clarity & stability
- Unopened product
- Follow its documented temperature, light protection, shipping and expiration requirements.
- Prepared material
- Chemical stability and microbial safety are formulation-specific. A diluent bottle's discard period does not establish the compound's storage period.
- Visible-change context
- Community clouding reports; generic formulation unresolved
Unexpected cloudiness, particles or gel
For a product intended to form a clear solution, do not use or attempt to salvage unexpected persistent clouding, strings, precipitate, thickening or gel. Labeled suspensions, including some triptorelin depots, have their own expected appearance and instructions.
Why vial yield does not establish shelf life
Arithmetic portions assume the material remains usable. Chemical degradation, contamination, handling losses and required discard limits may reduce practical yield. Freezing, warming, acidifying or further diluting cannot be assumed to restore quality.
No universal refrigerated, room-temperature or 90-day beyond-use period is assigned by the calculator.
How it works
GLP-1, GIP and glucagon receptor agonist
An investigational once-weekly triple receptor agonist with newly published phase 3 obesity data; it remains unavailable as an approved medicine.
Community-reported purpose
Appetite suppression, weight management, and broader metabolic research.
Reported purposes and marketing use-cases are not an approved indication or proof of efficacy.
Retatrutide is one triple-receptor agonist molecule, not a mixture of three separate drugs. Receptor activity and prolonged exposure do not independently determine an appropriate personal dose or combination regimen.
Clinical findings & study landscape
Obesity trial
338 adults; 48 weeks. Mean weight reduction in the 12 mg group was 24.2%, versus 2.1% with placebo. A group mean does not predict an individual's result.
Primary studyObesity without diabetes
2,339 participants. At 80 weeks, treatment-regimen mean weight changes were −17.6%, −23.7% and −25.0% at 4, 9 and 12 mg, versus −3.9% with placebo. These estimates must not be interchanged with on-treatment efficacy headlines.
Primary studyTRIUMPH-1 phase 3 trial
Protocol: 4, 9 or 12 mg target doses · subcutaneous · once weekly · 80 weeks · stepwise escalation
Population: Adults with obesity or overweight, without diabetes
Read the cited evidenceTRIUMPH-2 phase 3 trial
Protocol: 2 mg initiation; increased every 4 weeks through 4 and 6 mg, with a 9 mg step for the 12 mg arm · subcutaneous · once weekly · 80 weeks
Population: 1,152 adults with obesity or overweight and type 2 diabetes
Read the cited evidenceTRIUMPH-1-OSA and TRIUMPH-2-OSA
Protocol: 4, 9 or 12 mg target doses · subcutaneous · once weekly · 80 weeks; primary apnea–hypopnea endpoint assessed with 9 and 12 mg
Population: 243 adults without and 448 with type 2 diabetes; BMI at least 27 and moderate-to-severe obstructive sleep apnea
Read the cited evidenceFindings apply to the tested product, population and methods. A registry listing, mechanistic study or evidence-landscape link is not itself proof of efficacy or validation of an online vial.
Safety, evidence limits & regulatory status
Compound-specific safety context
Phase 3 adverse events were mainly gastrointestinal and generally mild to moderate; dysesthesia and urinary-tract infections were also reported. Long-term benefit-risk remains under regulatory review.
Development and regulatory status
Investigational — not FDA approved; U.S. submission planned for 2027
Approval of a named product does not extend to every vial, formulation, route, blend or indication carrying a related name.
What this guide cannot establish
The library does not authenticate a product or determine a personal starting dose, missed-dose rule, restart regimen, interaction plan or combination protocol. Study schedules, community reports and vial calculations retain separate evidence labels.
Frequently asked questions
What is Retatrutide?
An investigational once-weekly triple receptor agonist with newly published phase 3 obesity data; it remains unavailable as an approved medicine.
GLP-1, GIP and glucagon receptor agonist
Does vial strength mean the amount per administration?
No. A vial's label states nominal contents. The amount used in a study belongs to its assigned product and protocol. Changing vial strength changes concentration and yield, not the study's assigned amount.
Why does changing final volume change the U-100 value?
A larger final volume reduces concentration for the same mass. U-100 markings are volume measurements: one marking equals 0.01 mL. They are not biological international units of a peptide.
What happens when a calculation exceeds one syringe or vial?
Available mass and syringe capacity are separate limits. The calculator flags a result above 1 mL; it does not provide a splitting or combining technique.
Is there a loading phase or standard cycle?
A separate loading phase is not identified in this entry. Do not infer one from a range of reported amounts.
Community cycling unvalidated; phase 3 treatment lasted 80 weeks
Which diluent and storage period should this material use?
Clinical retatrutide trial products are not equivalent to an unspecified research powder. Community accounts describe cloudiness and experiments with BAC water, PBS and acidified solutions.
Calculation examples do not establish solvent compatibility, sterility or shelf life.
Where do I track or calculate a multi-phase schedule?
The Free Planner supports saved research examples and multi-phase planning. This guide's calculator is local to the page and does not save a protocol automatically.
Open Free PlannerReferences & evidence trail
- Clinical / regulatory / evidence landscapeNEJM, 2026: TRIUMPH-1 phase 3 trial
- Clinical / regulatory / evidence landscapeLancet, 2026: TRIUMPH-2 phase 3 trial
- Clinical / regulatory / evidence landscapeNEJM, October 2026 · randomized phase 3 nested trials: TRIUMPH-1-OSA and TRIUMPH-2-OSA
- Research study — applies to its stated conditionsRetatrutide phase-2 study
- Community/vendor report — unvalidatedRetatrutide cloudiness discussion
- Peer-reviewed study designTRIUMPH registrational design · Giblin et al.
- Peer-reviewed clinical trialPhase 2 obesity study · Jastreboff et al. · NEJM 2023
- Peer-reviewed clinical substudyPhase 2a liver-fat substudy · Sanyal et al. · Nature Medicine 2024
Clinical sources remain attached to their studies; laboratory and community formulation sources retain their own limits. Preparation review dates do not imply that every clinical study was newly reviewed today.
Independent educational research reference. Not medical advice or an individualized dosing recommendation.