Retatrutide

Also known as: LY3437943

Weight Loss Phase 3 Trials

GLP-1/GIP/Glucagon triple receptor agonist

Mechanism of Action

Activates GLP-1, GIP, and glucagon receptors. The glucagon component may enhance energy expenditure and fat oxidation beyond dual agonists.

Retatrutide (LY3437943) achieved up to 24.2% body weight reduction in 48 weeks in clinical trials — among the highest reported for any incretin-class compound. Currently in Phase 3 trials, it is the only investigational triple receptor agonist targeting GLP-1, GIP, and glucagon receptors simultaneously. The added glucagon activity may enhance energy expenditure and fat oxidation beyond dual agonists.

5,896
Community Posts
917
Users Discussing
32
Research Articles
22
Clinical Trials

Reported Outcomes

Clinical grade reflects published research; Community grade reflects user reports (n=5,896).

Weight Loss

Reduction in body weight

Clinical: A
Community: B
33% (694)

Retatrutide demonstrates profound efficacy in weight management, achieving up to 24.2% body weight reduction in 48 weeks. Meta-analyses consistently rank it as superior or highly potent compared to other incretins, with significant dose-dependent reductions in body mass index and waist circumference.

Appetite Suppression

Reduced hunger and food cravings

Clinical: A
Community: B
29% (550)

Clinical trials indicate significant reductions in overall appetite, hunger, and prospective food consumption, particularly at doses equal to or greater than 4 mg. Improvements in eating behaviors, such as reduced disinhibition and perceived hunger, correlate significantly with weight loss outcomes.

Sleep Quality

Effects on sleep quality

Clinical: C
Community: B
27% (523)
Energy Levels

Changes in energy and fatigue levels

Clinical: D
Community: B
20% (348)
Body Composition

Changes in muscle vs fat ratio

Clinical: B
Community: B
14% (195)

Treatment leads to substantial reductions in waist circumference and abdominal fat. While fat loss is significant, there is a noted reduction in lean mass, which is common with potent incretin therapies, necessitating attention to muscle preservation.

Mental/Mood

Effects on mood and cognitive function

Clinical: C
Community: B
11% (153)
Cardiovascular

Effects on heart health markers

Clinical: B
Community: B
10% (202)

The peptide significantly reduces systolic and diastolic blood pressure and improves lipid profiles, including reductions in triglycerides and LDL cholesterol. These effects contribute to an overall reduction in cardiometabolic risk factors.

Blood Sugar Control

Improved glycemic control and insulin sensitivity

Clinical: A
Community: B
10% (153)

Retatrutide significantly lowers fasting plasma glucose and HbA1c levels in patients with obesity and type 2 diabetes. Meta-analyses show it is highly effective at glycemic control, though some comparisons suggest tirzepatide may have a slight edge in this specific metric.

Who Discusses Retatrutide

From community reports with demographic data.

Gender

Male 63%
Female 37%

n=281

Age Distribution (limited data)

47.5
median age
range: 18-75
<30
30s
40s
50s
60+

n=68

Side Effects

Based on 478 user reports (n=478). Frequency indicates how often each was mentioned.

Common (>5%)

Fatigue
Mild 83 reports 12.1%
Constipation
Mild 65 reports 9.5%
Nausea
Mild 56 reports 8.2%

Uncommon (1-5%)

Insomnia
Mild 27 reports 3.9%
Stinging
Mild 26 reports 3.8%
Diarrhea
Mild 19 reports 2.8%
Tiredness
Mild 18 reports 2.6%
Food Noise
Mild 16 reports 2.3%
Water Retention
Mild 15 reports 2.2%
Injection Site Reaction (Isr)
Mild 15 reports 2.2%

Risks & Warnings

Important safety considerations based on clinical data and community reports.

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Pancreatitis

7 mentions

Rare but serious. Stop medication and seek care for severe persistent abdominal pain.

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Thyroid Concerns

27 mentions

GLP-1 agonists carry a boxed warning for thyroid C-cell tumors in rodents. Contraindicated in MEN2 or personal/family history of MTC.

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Gallbladder Issues

7 mentions

Rapid weight loss increases gallstone risk. Report severe abdominal pain to healthcare provider.

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Hypoglycemia Risk

27 mentions

Risk increases when combined with insulin or sulfonylureas. Monitor blood sugar carefully.

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Muscle Loss

22 mentions

Rapid weight loss may include muscle. Adequate protein intake and resistance training recommended.

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Psychiatric Effects

17 mentions

Monitor for mood changes. Report any concerning psychiatric symptoms to healthcare provider.

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Hair Loss

8 mentions

May occur with rapid weight loss. Usually temporary (telogen effluvium). Ensure adequate nutrition.

i

Gastrointestinal Issues

224 mentions

GI side effects are the most commonly reported. Usually improve over time with slow titration.

i

Injection Site Reactions

73 mentions

Local reactions are common and usually mild. Rotate injection sites.

Dosing

Standard Protocol

Starting Dose
1-2mg weekly (research protocols)
Titration
Titrate slowly over 4-8 weeks based on tolerance
Half-life
~6 days (estimated)
Administration
Subcutaneous injection, once weekly

Community Dosing Patterns

Based on 889 mentions

Community-reported patterns, not medical advice.

2mg weekly
67
4mg weekly
41
1mg weekly
38
5mg weekly
27
6mg weekly
24

Pricing

Research-grade reference pricing for 10mg vial. Prices vary by vendor and quantity. Research chemicals require self-mixing and lack medical oversight. Shipping is not included.

We do not list vendors. Prices are aggregated from community reports and should be treated as rough ranges.

US Research Grade

$100

Single small vial from US domestic vendors

US Research (Bulk)

$52.69

Per-dose equivalent when buying larger US vials

China Research

$5.88

Per-vial when buying 10-pack from Chinese vendors

Research

32
Total Articles
22
Clinical Trials
20
Reviews

Key Studies

Commonly Stacked With

Based on 5,896 community posts mentioning Retatrutide.

Cagrilintide 498 mentions (8.4%)
Tirzepatide 410 mentions (7%)
Semaglutide 228 mentions (3.9%)
MOTS-c 113 mentions (1.9%)
BPC-157 60 mentions (1%)

Switching Patterns

Based on 816 discussions about switching to or from Retatrutide.

Switching FROM

Tirzepatide 50 mentions
Semaglutide 27 mentions
Cagrilintide 27 mentions
Ipamorelin 4 mentions

Users who switched to Retatrutide

Switching TO

Cagrilintide 36 mentions
Tirzepatide 24 mentions
Semaglutide 11 mentions
Ipamorelin 6 mentions

Users who switched from Retatrutide

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