Retatrutide vs Semaglutide

Head-to-head evidence comparison — which supplement is right for you?

Quick answerNo interaction data — ask a pharmacist

Retatrutide vs Semaglutide: Semaglutide has the stronger overall evidence (8.5 vs 5.5/10); they're alternatives for manage weight — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.

Semaglutide Edges Ahead

Semaglutide wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.

Retatrutide0 wins

Semaglutide2 wins

Which is right for you? Take the 60-second quiz Open in the full comparison tool

Ret5.5

Retatrutide

Too few graded studiesLimited safety

Sgl8.5

Semaglutide

Too few graded studiesLimited safety

Evidence

Evidence Score

5.5/10

Studies: 52

Meta-analyses: 12

Level: Moderate

Evidence Score

Best8.5/10

Studies: 455

Meta-analyses: 134

Level: Very Strong

Research findings

Verdict

Too few graded studies

Top outcomes

Weight managementToo few graded studies40
Glucose & glycemic controlToo few graded studies27
Safety profileToo few graded studies10

Verdict

Too few graded studies

Top outcomes

Blood sugar & glycemic controlToo few graded studies197
Weight managementToo few graded studies182
Cardiovascular outcomesToo few graded studies58

Shared outcomes (2)

Outcomes where both Retatrutide and Semaglutide have evidence — compare verdict strength side-by-side.

Blood sugar & glycemic controlToo few graded studies27Too few graded studies197
Weight managementToo few graded studies40Too few graded studies182

Dosage & timing

Recommended Dosage:

SupStack does not provide a self-directed dosing protocol for Retatrutide. A dose used in a clinical trial does not establish a safe consumer dose. Phase-2 trials used once-weekly subcutaneous injection with stepwise escalation (e.g. start 2 mg) up to 8-12 mg maintenance.

Warnings

INVESTIGATIONAL DRUG — retatrutide is NOT a dietary supplement. The first phase-3 trial (type 2 diabetes, TRANSCEND-T2D-1) has reported, but the phase-3 obesity and cardio-kidney-outcome (TRIUMPH) program is still ongoing as of 2026; long-term safety, durability and hard clinical outcomes are unknown.
The largest reported weight loss (~24%) is genuinely striking, but it rests on a single phase-2 obesity trial; the first phase-3 (a T2D trial) showed ~15% weight loss, and there is still no phase-3 obesity confirmation of the ~24% figure and no cardiovascular/renal/mortality outcome data.
Grey-market 'retatrutide' sold online despite no approval is especially risky — it is an unapproved investigational drug with no clinical oversight, no identity/purity/sterility guarantee, and no dosing standard.
GLP-1-class effects apply: dose-related gastrointestinal events, gallbladder events, a pancreatitis class concern, and lean-mass loss alongside fat loss.
Glucagon-receptor agonism produced dose-dependent heart-rate increases and can transiently affect glucose; cardiovascular consequences are not yet characterised.
Expected GLP-1-class thyroid C-cell (medullary thyroid carcinoma) warning applies pending long-term human data.

Best Time:

Once a week

Can take on empty stomach

Best Form:

Once-weekly subcutaneous injection (investigational only)

Recommended Dosage:

Prescription-only, clinician-titrated. Subcutaneous (Wegovy weight management: escalate to 2.4 mg once weekly; Ozempic diabetes: 0.5-2.0 mg once weekly). Oral (Rybelsus diabetes: 3-14 mg once daily). DO NOT self-dose.

Warnings

This is a PRESCRIPTION DRUG, not a dietary supplement — use only under a clinician's care for an approved medical indication.
US FDA labeling includes a boxed warning about thyroid C-cell tumors: semaglutide caused these tumors in rodents; relevance to humans is uncertain. Under the US label it is contraindicated with a personal or family history of medullary thyroid carcinoma (MTC) or MEN2. For treatment in Germany or Austria, consult the current EU product information for the exact medicine’s locally approved indications, contraindications and warnings; discuss any thyroid history with the prescriber.
Risk of acute pancreatitis — discontinue and seek care for severe persistent abdominal pain.
Risk of gallbladder disease (gallstones, cholecystitis), particularly with rapid weight loss.
Gastrointestinal adverse effects (nausea, vomiting, diarrhea, constipation) are very common, especially during dose escalation.
Post-marketing reports of ileus (severely slowed gut motility).
May worsen pre-existing diabetic retinopathy, attributed to rapid improvement in glucose control — ensure ophthalmologic monitoring in patients with a history of diabetic retinopathy.
Weight loss includes loss of lean muscle mass — pair with resistance training and adequate protein.
FDA has warned about COMPOUNDED / grey-market semaglutide: risk of dosing errors, impurities, and unapproved salt forms. Use only pharmacy-dispensed product.
Not for cosmetic weight loss without a genuine medical indication.
May increase hypoglycemia risk when combined with insulin or sulfonylureas (dose adjustment needed).

Best Time:

Any time of day

Can take on empty stomach

Best Form:

Subcutaneous once-weekly injection (Ozempic / Wegovy)

Safety

Limited safetyTie

Drug Interactions:

Other GLP-1 / incretin drugs (severe)
Oral medications (delayed gastric emptying) (moderate)
Insulin / insulin secretagogues (sulfonylureas) (moderate)

Side Effects:

Nausea / vomitingDiarrhoea / constipationIncreased heart rate

Contraindications:

Not a dietary supplement and not an approved drug — investigational; do not self-source grey-market vials
Personal/family history of medullary thyroid carcinoma or MEN 2 (expected GLP-1-class thyroid C-cell precaution, not a product-label contraindication: this investigational drug has no label, and not every approved GLP-1 product carries the US thyroid boxed warning)

Limited safetyTie

Drug Interactions:

Other GLP-1 receptor agonists (severe)
Insulin and sulfonylureas (moderate)
Oral medications (general) (moderate)

Side Effects:

NauseaVomiting / diarrhea / constipationGallbladder disease (cholelithiasis / cholecystitis)

Contraindications:

Personal or family history of medullary thyroid carcinoma (MTC) (a contraindication under the US label)
Multiple Endocrine Neoplasia syndrome type 2 (MEN2) (a contraindication under the US label)

Shared goals

Manage weightSemaglutide

Retatrutide68/100

Semaglutide88/100

Manage blood sugarSemaglutide

Retatrutide58/100

Semaglutide85/100

Metabolic healthSemaglutide

Retatrutide56/100

Semaglutide70/100

What you'll notice

⚖️ Large weight loss (phase-2 only)positive

Progressive over 24-48 weeks

🫀 Liver-fat reduction (MASLD substudy)positive

By 24 weeks

🩸 Improved glycemic controlpositive

By 24-36 weeks

🤢 Gastrointestinal adverse eventstrade-off

Especially during dose escalation

🩸 Improved glycemic controlpositive

Weeks to months

⚖️ Substantial weight losspositive

Months (titrated over 16-20 weeks)

❤️ Reduced cardiovascular eventspositive

Months to years

🤢 GI adverse effects (very common)trade-off

Especially during dose escalation

Key studies

Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial.

N Engl J Med (2023) · Rct · n=338

Phase-2, double-blind, randomized, placebo-controlled trial in 338 adults with obesity (or overweight + a weight-related condition), once-weekly subcutaneous retatrutide 1-12 mg vs placebo for 48 weeks

Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo and active-controlled, parallel-group, phase 2 trial conducted in the USA.

Lancet (2023) · Rct · n=281

Phase-2, double-blind, double-dummy, placebo- and active-comparator (1.5 mg dulaglutide)-controlled trial in 281 adults with type 2 diabetes, once-weekly retatrutide 0.5-12 mg over 36 weeks

Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trial.

Nat Med (2024) · Rct · n=98

Phase-2a, randomized, double-blind, placebo-controlled MASLD substudy (n=98) of the obesity trial, in participants with ≥10% liver fat, once-weekly retatrutide 1-12 mg vs placebo

All Retatrutide studies

Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1).

N Engl J Med (2021) · Rct · n=1961

Double-blind RCT in 1,961 adults with obesity/overweight WITHOUT diabetes, randomized 2:1 to subcutaneous semaglutide 2.4 mg/week or placebo plus lifestyle for 68 weeks

Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes (SELECT).

N Engl J Med (2023) · Rct · n=17604

Large cardiovascular-outcomes RCT: 17,604 patients with preexisting cardiovascular disease and overweight/obesity but WITHOUT diabetes

Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes (SUSTAIN-6).

N Engl J Med (2016) · Rct · n=3297

Pre-approval cardiovascular-safety RCT in 3,297 patients with type 2 diabetes at high cardiovascular risk, semaglutide (0.5/1.0 mg/week) vs placebo for 104 weeks

All Semaglutide studies

Frequently asked questions

Is Retatrutide better than Semaglutide?

Semaglutide has a higher evidence score (8.5/10 vs 5.5/10) and wins in 2 of 3 categories.

Is Retatrutide or Semaglutide better for manage weight?

For manage weight, Semaglutide has a higher relevance score (88 vs 68).

Can I take Retatrutide and Semaglutide together?

No documented interaction was found in the data searched. This does not establish that this exact combination is safe.

Related comparisons

Retatrutide vs Whey Protein Retatrutide vs Tirzepatide Liraglutide vs Retatrutide Semaglutide vs Tirzepatide Liraglutide vs Semaglutide AREDS2 Formula vs Semaglutide

Still deciding between Retatrutide and Semaglutide?

The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.

Get your personalised pick Retatrutide details Semaglutide details

Warnings

INVESTIGATIONAL DRUG — retatrutide is NOT a dietary supplement. The first phase-3 trial (type 2 diabetes, TRANSCEND-T2D-1) has reported, but the phase-3 obesity and cardio-kidney-outcome (TRIUMPH) program is still ongoing as of 2026; long-term safety, durability and hard clinical outcomes are unknown.

The largest reported weight loss (~24%) is genuinely striking, but it rests on a single phase-2 obesity trial; the first phase-3 (a T2D trial) showed ~15% weight loss, and there is still no phase-3 obesity confirmation of the ~24% figure and no cardiovascular/renal/mortality outcome data.

Grey-market 'retatrutide' sold online despite no approval is especially risky — it is an unapproved investigational drug with no clinical oversight, no identity/purity/sterility guarantee, and no dosing standard.

GLP-1-class effects apply: dose-related gastrointestinal events, gallbladder events, a pancreatitis class concern, and lean-mass loss alongside fat loss.

Glucagon-receptor agonism produced dose-dependent heart-rate increases and can transiently affect glucose; cardiovascular consequences are not yet characterised.

Expected GLP-1-class thyroid C-cell (medullary thyroid carcinoma) warning applies pending long-term human data.

Warnings

This is a PRESCRIPTION DRUG, not a dietary supplement — use only under a clinician's care for an approved medical indication.

US FDA labeling includes a boxed warning about thyroid C-cell tumors: semaglutide caused these tumors in rodents; relevance to humans is uncertain. Under the US label it is contraindicated with a personal or family history of medullary thyroid carcinoma (MTC) or MEN2. For treatment in Germany or Austria, consult the current EU product information for the exact medicine’s locally approved indications, contraindications and warnings; discuss any thyroid history with the prescriber.

Risk of acute pancreatitis — discontinue and seek care for severe persistent abdominal pain.

Risk of gallbladder disease (gallstones, cholecystitis), particularly with rapid weight loss.

Gastrointestinal adverse effects (nausea, vomiting, diarrhea, constipation) are very common, especially during dose escalation.

Post-marketing reports of ileus (severely slowed gut motility).

May worsen pre-existing diabetic retinopathy, attributed to rapid improvement in glucose control — ensure ophthalmologic monitoring in patients with a history of diabetic retinopathy.

Weight loss includes loss of lean muscle mass — pair with resistance training and adequate protein.

FDA has warned about COMPOUNDED / grey-market semaglutide: risk of dosing errors, impurities, and unapproved salt forms. Use only pharmacy-dispensed product.

Not for cosmetic weight loss without a genuine medical indication.

May increase hypoglycemia risk when combined with insulin or sulfonylureas (dose adjustment needed).

Frequently asked questions

Is Retatrutide better than Semaglutide?

Semaglutide has a higher evidence score (8.5/10 vs 5.5/10) and wins in 2 of 3 categories.

Is Retatrutide or Semaglutide better for manage weight?

For manage weight, Semaglutide has a higher relevance score (88 vs 68).

Can I take Retatrutide and Semaglutide together?

No documented interaction was found in the data searched. This does not establish that this exact combination is safe.