The Sculptique Aesthetics
Retatrutide Dosage Guide: Triple Agonist Weight Loss Protocol for India & Mumbai (2026)
Retatrutide dosage — the triple GLP-1/GIP/glucagon agonist showing 24% weight loss in trials. Complete dose escalation, safety, comparison to Mounjaro and Ozempic, and medically supervised protocols from The Sculptique Aesthetics Mumbai.
Retatrutide dosage — this is the protocol for what many clinicians are calling the next generation of weight-loss medicine. Retatrutide (LY3437943) is a triple receptor agonist: it simultaneously targets GLP-1, GIP and glucagon receptors. In Phase 2 clinical trials, retatrutide at 12 mg weekly produced an average weight loss of 24.2 % of body weight at 48 weeks — surpassing every prior single trial result for a weight-loss drug, including tirzepatide (Mounjaro) and semaglutide (Ozempic).
If you're searching for retatrutide dosage, how much retatrutide to inject, retatrutide dose escalation, retatrutide 4 mg vs 8 mg vs 12 mg, retatrutide compared to Ozempic and Mounjaro, or retatrutide side effects, this guide covers the clinical trial protocols and what supervised use looks like. The Sculptique Aesthetics offers advanced weight-loss peptide protocols in Mumbai, Bandra, Khar, Andheri, South Mumbai and across India.
Important: retatrutide is currently in Phase 3 trials as of 2026 and is not yet FDA-approved or commercially available in most countries including India. Access in India requires participation in a clinical trial, compassionate use pathway, or through specific research settings. We discuss the current access landscape at consultation.
What is retatrutide? How does it differ from tirzepatide and semaglutide?
The three GLP-1 agonist drugs differ in how many receptor pathways they activate:
| Drug | Receptors activated | Mechanism |
|---|---|---|
| Semaglutide (Ozempic/Wegovy) | GLP-1 | Appetite suppression, slows gastric emptying |
| Tirzepatide (Mounjaro) | GLP-1 + GIP | Dual action: appetite + fat metabolism |
| Retatrutide | GLP-1 + GIP + Glucagon | Triple action: appetite + fat metabolism + thermogenesis |
The addition of the glucagon receptor is retatrutide's key differentiator. Glucagon increases energy expenditure (thermogenesis) and fat oxidation — essentially, the body burns more calories even at rest. This third pathway is why retatrutide's weight loss data exceeds both predecessors despite similar GI side effect profiles.
For comparison, see Ozempic vs Mounjaro (tirzepatide) and the full retatrutide overview.
Retatrutide dosage: Phase 2 clinical trial protocols
The Phase 2 retatrutide trial (NEJM 2023) tested multiple escalation schedules. These are the doses and outcomes from the published data:
Phase 2 dose escalation groups
Group 1 (Low dose, slow escalation):
| Weeks | Dose |
|---|---|
| Weeks 1–4 | 1 mg SC weekly |
| Weeks 5–8 | 2 mg SC weekly |
| Weeks 9–24 | 4 mg SC weekly (maintenance) |
Average weight loss at 24 weeks: ~8.7 %
Group 2 (Medium dose):
| Weeks | Dose |
|---|---|
| Weeks 1–4 | 2 mg SC weekly |
| Weeks 5–8 | 4 mg SC weekly |
| Weeks 9–24 | 8 mg SC weekly (maintenance) |
Average weight loss at 24 weeks: ~12.9 %
Group 3 (High dose, standard escalation):
| Weeks | Dose |
|---|---|
| Weeks 1–4 | 2 mg SC weekly |
| Weeks 5–8 | 4 mg SC weekly |
| Weeks 9–12 | 8 mg SC weekly |
| Weeks 13–24 | 12 mg SC weekly (maintenance) |
Average weight loss at 24 weeks: ~17.5 %; at 48 weeks: ~24.2 %
Group 4 (High dose, fast escalation):
| Weeks | Dose |
|---|---|
| Weeks 1–4 | 4 mg SC weekly |
| Weeks 5–8 | 8 mg SC weekly |
| Weeks 9–24 | 12 mg SC weekly (maintenance) |
Higher side effect rate vs Group 3 — the slower standard escalation is better tolerated.
Retatrutide dosage quick-reference
| Dose | Use | Expected weight loss (48+ weeks) |
|---|---|---|
| 4 mg/week | Conservative / low-dose maintenance | ~8–10 % |
| 8 mg/week | Intermediate | ~13–16 % |
| 12 mg/week | Maximum studied dose (high efficacy) | ~22–24 % |
These are Phase 2 research figures. Phase 3 protocols may refine these numbers. Individual results depend on dietary adherence, activity and metabolic baseline.
Retatrutide weight loss data vs competitors
| Drug | Best clinical trial weight loss | Trial duration |
|---|---|---|
| Semaglutide 2.4 mg | ~12–15 % | 68 weeks (STEP) |
| Tirzepatide 15 mg | ~20.9 % | 72 weeks (SURMOUNT-1) |
| Retatrutide 12 mg | ~24.2 % | 48 weeks (Phase 2) |
| Retatrutide 12 mg (projected to 72 weeks) | Estimated 26–30 % | Phase 3 ongoing |
Retatrutide's superiority is particularly striking given it achieves greater weight loss in less time (48 vs 68–72 weeks).
Retatrutide injection protocol
- Route: subcutaneous injection (pre-filled pen — format under development for commercial release)
- Frequency: once weekly, same day each week
- Sites: abdomen, thigh, upper arm — rotate each week
- Timing with meals: no dietary restriction on injection timing
- Storage: refrigerate at 2–8 °C; avoid freezing
Retatrutide side effects by dose
Retatrutide's side effect profile is similar to tirzepatide but with slightly higher nausea rates at the 8–12 mg doses — likely due to the glucagon component's additional gastrointestinal activity.
Common (GI — dose-escalation dependent)
- Nausea — most common; peaks during escalation, particularly at the jump to 8 mg and 12 mg. Manage: evening injection, small meals, no fatty food
- Vomiting — if frequent: pause escalation, stay at previous dose
- Diarrhoea — early and dose-dependent; usually resolves within 2–4 weeks at each level
- Constipation — less common than with semaglutide; increase water and fibre
- Reduced appetite — intended effect; monitor for under-eating
Specific to glucagon receptor activation
- Slightly elevated heart rate (mild tachycardia) — glucagon activates the sympathetic nervous system; typically resolves after weeks 1–4 at new dose
- Increased energy expenditure may cause sweating or mild warmth — the thermogenic effect; not dangerous
Rare and serious
- Pancreatitis — rare; any severe upper abdominal pain: stop and seek emergency care
- Thyroid (theoretical): as with all GLP-1 agonists, precaution with personal/family history of medullary thyroid carcinoma or MEN2
Contraindications for retatrutide
- Personal or family history of medullary thyroid carcinoma or MEN2
- Pancreatitis history
- Pregnancy and breastfeeding
- Severe renal or hepatic impairment (Phase 3 data pending for these populations)
Retatrutide vs tirzepatide: which should I choose?
Both are options worth discussing at The Sculptique Aesthetics. The practical guidance:
- Tirzepatide (Mounjaro): approved, commercially available, well-characterised 72-week safety profile, ~20 % average weight loss. Best current option for most patients with obesity.
- Retatrutide: superior Phase 2 efficacy (~24 % at 48 weeks), Phase 3 results awaited, not yet widely commercially available. For patients who respond partially to tirzepatide or want the cutting-edge protocol when access allows.
See full tirzepatide dosage guide and retatrutide overview.
Retatrutide and muscle preservation
With 24 % body weight loss comes significant risk of lean mass loss (same concern as with tirzepatide and semaglutide, amplified). At The Sculptique Aesthetics we always pair advanced weight-loss peptides with:
- Protein target: ≥1.5 g/kg/day (based on current, not target, body weight)
- Resistance training: 3+ sessions weekly
- CJC-1295 / Ipamorelin: GH peptide protocol for lean tissue preservation
- NAD+ IV therapy: for metabolic energy support during aggressive weight loss
Availability of retatrutide in India (2026 update)
As of 2026, retatrutide (LY3437943, being developed by Eli Lilly) is in Phase 3 clinical trials. Commercial approval is anticipated in 2026–2027 in the US, with India following. For patients in India seeking access:
- Clinical trial participation: the most reliable route; check registrations through CTRI (Clinical Trials Registry India) or Clinicaltrials.gov
- Compassionate use / expanded access: possible in select cases through specialist referral
- Medical tourism: some patients access it during travel to markets where it becomes available
At The Sculptique Aesthetics we stay current on approval status and advise patients on realistic access options at the time of consultation.
Frequently asked questions
From Phase 2 protocols: 1–2 mg SC once weekly for the first 4 weeks. The slow escalation (Group 3 protocol) starting at 2 mg → 4 mg → 8 mg → 12 mg showed the best tolerability alongside high efficacy.
12 mg SC once weekly — the highest Phase 2 dose, associated with ~24.2 % average body weight loss at 48 weeks. Phase 3 may test higher doses.
In Phase 2 data, yes — retatrutide 12 mg produced greater average weight loss (~24 %) than tirzepatide 15 mg (~21 %) in its respective trial. However, direct head-to-head trials have not been completed, and Phase 2 vs Phase 2 comparisons have limitations. Based on available data, retatrutide appears to be the more potent compound.
Phase 2 data shows a side effect profile similar to tirzepatide — GI effects dominate and are largely manageable through slow escalation. No unexpected safety signals were identified. Long-term safety data will come from Phase 3 trials. See are peptides safe.
They are not dose-equivalent. Semaglutide is dosed at 0.25–2.4 mg weekly; retatrutide at 1–12 mg weekly. The drugs have different pharmacology — dose comparison is not clinically meaningful without understanding the receptor targets.
Phase 2 maintenance doses varied by group: 4 mg, 8 mg or 12 mg weekly. The lowest effective maintenance dose will be determined by Phase 3 data. At The Sculptique Aesthetics, once Phase 3 results are published, we will calibrate maintenance protocols accordingly.
As of April 2026, retatrutide is not commercially available in India. Phase 3 trials are ongoing; regulatory approval is expected in 2026–2027. We advise on access pathways at consultation.
Book your weight-loss peptide consultation in Mumbai
Whether your best option today is semaglutide, tirzepatide or accessing the emerging retatrutide protocols, the right starting point is a comprehensive clinical assessment — not choosing a drug from online forums.
At The Sculptique Aesthetics, we match patients to the right weight-loss protocol based on BMI, metabolic health, comorbidities, previous treatment response and lifestyle. We combine medication with body composition monitoring, dietary guidance and, where appropriate, supporting peptide therapy and NAD+ IV to optimise the result.
Contact us to start your assessment. Serving Mumbai, Bandra, Khar, Andheri, Powai, Juhu, South Mumbai and international patients seeking supervised medical weight loss in India.
