Deep Dive: Peptide Research

Updated: January 31, 2026

IMPORTANT DISCLAIMER: This page compiles available research on peptides commonly discussed in fitness and longevity communities. These are research chemicals, not FDA-approved medications. Nothing here constitutes medical advice or an endorsement for use. This is purely educational—helping you understand what the research does (and doesn’t) show. Always consult qualified healthcare professionals before considering any peptide use.

⚠️ IMPORTANT: If You’re 18-25

Your brain is still developing until age 25. This possibly can create unique risks that most peptide content completely ignores.

Before reading about any of these peptides, understand what the research shows about young adult brain development and why it matters.

Peptides and Young Adults (18-25)

What This Page Covers

You’ve probably seen peptides all over social media—promises of faster recovery, better skin, enhanced healing. The marketing is everywhere, but the actual research? Much harder to “digest” in plain language.

This page breaks down what peer-reviewed studies actually show about four commonly discussed peptides:

Melanotan II (MT2) – Synthetic tanning agent
BPC-157 – “Healing peptide” popular in athletic recovery
GHK-Cu – Copper peptide for skin and anti-aging
TB-500 – Recovery and inflammation peptide
Retatruetide “Reta”– Weight loss, obesity treatment

How to Read This Research

Not all studies carry the same weight. Here’s the variety of evidence, from strongest to weakest:

Study Quality Hierarchy:

Randomized Controlled Trials (RCTs) in Humans – Gold standard
Human Observational Studies – Useful but can’t prove causation
Animal Studies – Shows possibility, not proof in humans
In-Vitro Studies – Cells in a dish; very preliminary

When you see claims about peptides, ask: Where does the evidence actually come from? Most of what you’ll find below sits firmly in categories 3 and 4.

Melanotan II (MT2)

Chemical Name: [Nle4, D-Phe7]-α-MSH

Common Use: Synthetic tanning, erectile dysfunction

Regulatory Status: Not FDA approved; banned by WADA

Efficacy – Tanning

MT2 is one of the few peptides on this list with actual published human trials. A 1996 Phase I study tested MT2 in three healthy male volunteers at doses ranging from 0.01 to 0.03 mg/kg via subcutaneous injection over two weeks. The results showed measurable skin pigmentation in two subjects within one week after dosing ended, even without UV exposure. The mechanism is well-understood: MT2 activates melanocortin-1 receptors (MC1R) in melanocytes, stimulating melanin production throughout the skin. This produces a diffuse tan that doesn’t require sun exposure and can darken existing moles and freckles.

Efficacy – Erectile Function

Small Human Studies

MT2 also demonstrated unexpected effects on sexual function. In a double-blind, placebo-controlled study of 20 men with erectile dysfunction, MT2 initiated penile erections in 17 of 20 participants without sexual stimulation. Mean duration of rigidity exceeded 38 minutes with MT2 versus approximately 3 minutes with placebo. In 68% of doses, subjects reported increased sexual desire.

Safety Profile

Limited Long-Term Data

Common side effects reported across studies include: – Nausea (most common, especially at higher doses) – Facial flushing – Yawning and stretching (appears to correlate with erectile effects) – Spontaneous erections lasting 1-5 hours – Darkening of existing moles and new pigmented lesions.

**[Critical safety concern]**

The darkening and proliferation of pigmented lesions raised early questions about potential melanoma risk. No large-scale trials were ever conducted to evaluate long-term cancer risk, which contributed to the compound never receiving FDA approval.

Research Gaps

No published long-term safety data beyond a few weeks
Unknown melanoma risk from chronic use
No large-scale controlled trials
Quality control concerns with black market sources

My Take on MT2

MT2 actually has human trial data showing it works for tanning and erectile function—more than most peptides can claim. But “works” doesn’t mean “safe for casual use.” The mole-darkening effects and complete lack of long-term safety data are serious concerns. This was studied as a potential pharmaceutical with medical supervision, not as a cosmetic product ordered online.

If you’re considering MT2 for tanning, you’re essentially participating in an uncontrolled experiment on yourself. The research exists, but it stops short of the safety data you’d want before using it long-term.

BPC-157

Chemical Name: Body Protection Compound-157

Common Use: Tissue repair, healing injuries, gut health

Regulatory Status: Not FDA approved; FDA Category 2 (insufficient safety data); previously banned by WADA

What the Research Shows

Here’s the critical fact about BPC-157:

There are virtually zero published peer-reviewed human trials. A 2025 systematic review screened 544 papers and found only 36 studies that met inclusion criteria. Of those 36 studies, 35 were animal or cell studies. Only ONE study involved humans—a tiny 12-person retrospective case series with no control group, no blinding, and no standardized outcome measures. That’s the lowest level of clinical evidence possible.

In that single study, patients with chronic knee pain received intra-articular injections of BPC-157 (some combined with TB-500). Seven out of twelve reported pain relief lasting at least six months. But with no control group, no imaging, and no standardized measurements, it’s impossible to attribute improvement specifically to the peptide.

Two additional small pilot studies exist: one on intravenous safety/pharmacokinetics in 2 healthy adults (showing no adverse effects at 20mg doses), and clinical trials for inflammatory bowel disease conducted in Croatia in the early 2000s that showed it was well-tolerated.

Animal Research:

The vast majority of BPC-157 research comes from animal models—primarily rats—conducted by one research group in Croatia. These studies consistently show positive effects:

Accelerated tendon healing with higher load-to-failure strength.
Faster ligament repair.
Improved muscle recovery.
Bone fracture healing comparable to bone-marrow grafts.
Protection against NSAID-induced gut damage.
Improved outcomes in inflammatory bowel disease models.

The proposed mechanism involves enhancement of growth factor expression (particularly growth hormone receptor, VEGF, and FGF) and modulation of inflammatory pathways.

Safety Profile

Animal toxicology studies found BPC-157 well-tolerated with no identifiable minimum toxic dose or lethal dose. No teratogenic, genotoxic, anaphylactic, or local toxic effects were reported in preclinical testing. The peptide has a half-life under 30 minutes and is metabolized in the liver and cleared by the kidneys.

However:

There are zero large-scale human safety trials. All the safety data comes from animals. Given the unregulated nature of peptide markets, contamination is a significant concern—studies suggest 12-58% of peptide products contain contaminants or incorrect dosing.

Research Gaps

No controlled human trials for injury healing

Unknown long-term safety in humans
No established dosing protocols for humans
Mechanism of action not fully understood
Product quality highly variable (unregulated market)
Potential publication bias (only positive results published)

My Take on BCP-157

BPC-157 is the poster child for the gap between hype and evidence. Yes, it looks promising in rats. Yes, the mechanism makes sense theoretically. But calling it a “proven healing peptide” is a massive overstatement.

We have 30+ years of animal research and essentially zero human clinical trials. The one tiny human study that exists wouldn’t even make it past peer review in a major journal. The FDA classifies it as Category 2 specifically because we don’t know if it’s safe in humans.

This doesn’t mean it doesn’t work—it means we genuinely don’t know. If someone is using BPC-157 and claims it helped their injury, they might be right. But they’re also part of an uncontrolled experiment with unknown risks and no quality control on what they’re actually injecting.

The biggest red flag? The dramatic difference between what rodent studies show and what human evidence exists. Until we have proper clinical trials, this remains firmly in “experimental” territory.

GHK-Cu (Copper Peptide)

Chemical Name: Glycyl-L-Histidyl-L-Lysine (copper complex)

Common Use: Anti-aging, wound healing, skin regeneration

Regulatory Status: Widely used in cosmetics; not FDA approved for injectable use

What the Research Shows

GHK-Cu is a naturally occurring tripeptide found in human plasma, saliva, and urine. It was first isolated in 1973 from human albumin. Unlike BPC-157, GHK-Cu actually exists in your body—plasma levels are around 200 ng/mL at age 20 but decline to approximately 80 ng/mL by age 60. The peptide has a high affinity for copper (II) ions and forms a stable complex called GHK-Cu. It’s proposed to function primarily as this copper complex, modulating copper intake into cells and activating various cellular pathways involved in tissue repair and remodeling.

Human Evidence – Topical Use

GHK-Cu has more human data than BPC-157, particularly for topical (skin) applications:

A randomized, double-blind clinical trial tested GHK-Cu encapsulated in nano-lipid carriers applied twice daily for 8 weeks. Female volunteers showed measurable improvements in:

Increased skin thickness (epidermis and dermis)
Improved skin hydration
Significant skin smoothing
Increased skin elasticity
Stimulation of collagen I production

Multiple controlled facial studies from the 1980s-2000s demonstrated anti-aging, firming, and anti-wrinkle activity, though sample sizes were relatively small (typically under 50 participants) and duration of use was short.

Human Evidence – Would Healing

Limited Controlled Studies

Howard Maibach’s research group tested copper peptide complexes in four human wound healing systems. In all four studies, there was more rapid healing with creams containing copper peptide complexes compared to control creams. There was also faster reduction in erythema (redness) in nickel allergy patients. However, these studies were relatively small and short-term. Most wound healing data still comes from animal models.

Animal Testing Evidence

GHK-Cu has been extensively studied in animals, particularly rats, mice, and pigs:

Systemic healing enhancement: Injecting GHK-Cu in one body area (thigh) improved healing at distant areas (ears)
Wound closure: In ischemic skin flaps, wound size decreased 64.5% in GHK-Cu group vs 28.2% in control group
Collagen production: Stimulates synthesis at picomolar to nanomolar concentrations
Gene expression: The Broad Institute measured effects on over 13,000 human genes, finding GHK modulates thousands of genes related to tissue repair, inflammation, and oxidative stress

Safety Profile

Excellent for Topical; Unknown for Injectable.

GHK-Cu has decades of safe use in cosmetic products with an excellent safety record. No significant adverse effects have been reported in topical applications or human wound healing studies.

Important distinction: Most safety data applies to topical use. Injectable GHK-Cu has far less human safety data, and excessive copper can be toxic. Copper poisoning is a real concern if dosing is not properly managed.

Research Gaps

Limited data on injectable GHK-Cu in humans
Optimal dosing protocols not well-established for systemic use
Long-term effects of chronic injectable use unknown
Copper toxicity thresholds in peptide form unclear
Most anti-aging claims based on gene expression data, not clinical outcomes

My Take on GHK-Cu

GHK-Cu sits in a different category than BPC-157. It’s a naturally occurring peptide with decades of research, actual human trials for topical use, and a strong safety record in cosmetics. The mechanism makes sense, and the cosmetic industry has validated its efficacy for skin health.

For topical use (creams, serums), the evidence is solid. Multiple studies show real benefits for skin aging, wound healing, and collagen production. If you’re using GHK-Cu in a face cream, you’re on relatively firm scientific ground.

For injectable use? That’s where it gets murkier. The animal data is compelling, and the gene expression studies are fascinating, but we don’t have the same level of human clinical trials for systemic/injectable applications.

The recent social media trend of people buying lab-grade powder and self-injecting is concerning—copper toxicity is real, and there’s no quality control or medical supervision.

Bottom line: Topical GHK-Cu has legitimate scientific support. Injectable GHK-Cu has promising preclinical data but lacks the human clinical trials needed to call it “proven.”

TB-500 (Thymosin Beta-4)

Chemical Name: Thymosin Beta-4 (synthetic fragment)

Common Use: Tissue repair, recovery, inflammation reduction

Regulatory Status: Not FDA approved; banned by WADA

What the Research Shows

TB-500 is a synthetic version of Thymosin Beta-4, a naturally occurring peptide involved in cell migration, tissue repair, and wound healing. Like GHK-Cu, it’s actually present in your body. TB-4 is released by platelets and various cell types in response to injuryMultiple controlled facial studies from the 1980s-2000s demonstrated anti-aging, firming, and anti-wrinkle activity, though sample sizes were relatively small (typically under 50 participants) and duration of use was short.

Human Evidence

Extremely Limited

TB-500 has even less human research than BPC-157. There are no published peer-reviewed randomized controlled trials in humans specifically for athletic recovery or injury healing.

One small retrospective study (mentioned in the BPC-157 section) tested a combination of BPC-157 + TB-500 for knee pain, but this doesn’t allow us to isolate TB-500’s specific effects.

Most TB-4 research in humans has focused on cardiovascular applications and wound healing in clinical settings, but these studies used different formulations and protocols than the TB-500 products circulating in athletic communities.

Animal Testing Evidence

Animal studies show TB-4/TB-500 promotes:

Cell migration to injury sites
New blood vessel formation (angiogenesis)
Reduced inflammation
Improved wound healing
Enhanced tissue repair in heart, muscle, and connective tissue

he mechanism appears to involve actin regulation, which affects cell movement and structure—important for tissue repair and remodeling.

Safety Profile

Insufficient Human Data

No comprehensive human safety trials exist for TB-500 as used in athletic/recovery contexts. Animal studies suggest it’s well-tolerated, but extrapolating animal safety data to humans is always problematic. Like all unregulated peptides, product quality and contamination are major concerns.

Research Gaps

No controlled human trials for athletic recovery
Unknown optimal dosing in humans
Long-term safety completely unknown
Difference between natural TB-4 and synthetic TB-500 unclear
No quality control standards for commercial products

My Take on TB-500

TB-500 falls into the same category as BPC-157: promising animal data, plausible mechanism, essentially zero human clinical evidence.

Retatrutide (Triple Agonist) or “Reta”

Chemical Name: Y3437943 (GIP/GLP-1/Glucagon receptor triple agonist)

Common Use: Weight loss, obesity treatment

Regulatory Status: Investigational (Phase 3 trials ongoing); not FDA approved; developed by Eli Lilly

What the Research Shows (Phase 2-3 Trials)

Retatrutide represents a fundamentally different approach than the peptides above. This is a pharmaceutical-grade medication in active clinical development by Eli Lilly, not a research chemical bought online. It’s a single molecule that activates three different hormone receptors simultaneously:

GLP-1 receptor: Controls appetite and blood sugar (same target as Ozempic/Wegovy)
GIP receptor: Enhances insulin secretion and affects fat metabolism (same as Mounjaro/Zepbound)
Glucagon receptor: Increases energy expenditure and fat burning (unique addition)

This “triple agonist” approach is designed to combine the appetite suppression effects of GLP-1 drugs with additional metabolic benefits from glucagon activation.

Human Evidence – Phase 2 Trial

Randomized Controlled Trial – High Quality

The landmark Phase 2 trial published in the New England Journal of Medicine in 2023 represents some of the most impressive weight loss data from any pharmaceutical ever tested:

Study Design:

338 adults with obesity (BMI ≥30) or overweight (BMI ≥27 with complications), randomized to placebo or retatrutide at various doses (1mg, 4mg, 8mg, or 12mg) weekly for 48 weeks.

Results at 48 weeks:

12mg dose: Average weight loss of 24.2% (approximately 58 pounds)
8mg dose: Average weight loss ranging from 21.7% to 23.9% depending on dose escalation
4mg dose: Average weight loss ranging from 16.3% to 17.8%
1mg dose: Average weight loss of 8.7%
Placebo: Weight loss of 2.1%

Remarkable efficacy data:

With the 12mg dose, 91% of participants lost ≥10% of body weight
64% lost ≥20%
48% lost ≥25%
26% lost ≥30%

These results are comparable to bariatric surgery and represent a paradigm shift in pharmaceutical obesity treatment. Importantly, participants had not reached a weight plateau by week 48, suggesting even greater weight loss with longer treatment.

Human Evidence – Phase 3 Trial

Multiple Large-Scale RCTs – Highest Quality

In December 2024, Eli Lilly announced topline results from TRIUMPH-4, the first successful Phase 3 trial:

Study Population: 445 adults with obesity/overweight AND knee osteoarthritis
Duration: 68 weeks
Doses tested: 9mg and 12mg (with stepwise dose escalation)

Results (efficacy estimand)

12mg dose: Average weight loss of 28.7% (71.2 pounds)
9mg dose: Average weight loss of 26.4% (58 pounds)
Placebo: Weight loss of 2.1% (2.1 Pounds)

Additional benefits beyond weight loss:

Significant reduction in knee pain (WOMAC pain score improved 4.4-4.5 points vs 2.4 with placebo)
Improved physical function
Improvements in cardiovascular risk markers (cholesterol, triglycerides, C-reactive protein)

The TRIUMPH Phase 3 program includes multiple trials evaluating retatrutide for:

Chronic weight management
Obstructive sleep apnea
Knee osteoarthritis in obesity
Over 5,800 participants enrolled across trials

Additional Phase 3 results expected throughout 2026.

Safety Profile

Well-Documented in Clinical Trials

Retatrutide’s safety profile is similar to other incretin-based therapies (like semaglutide and tirzepatide), with gastrointestinal side effects being most common:

Common side effects:

Nausea: 38-43% (vs 11% placebo)
Diarrhea: 33-35% (vs 13% placebo)
Constipation: 22-25% (vs 9% placebo)
Vomiting: 20-21% (vs 5% placebo)

Most GI side effects occurred during dose escalation and decreased over time. The stepwise dose escalation protocol (starting at 2mg and increasing gradually) was designed to minimize these effects.

Notable safety findings:

No cases of medullary thyroid cancer or C-cell hyperplasia reported
No clinically significant hypoglycemia in non-diabetic participants
Some participants discontinued due to “perceived excessive weight loss” (especially those with higher baseline BMI)
Discontinuation rates due to adverse events: 8.8-12.1% (9-12mg doses) vs 4.8% placebo

Important distinction from other peptides:

Retatrutide is being developed under full FDA oversight with rigorous Phase 1-3 clinical trials. This is pharmaceutical development, not unregulated research chemicals.

Metabolic Benefits Beyond Weight Loss

Clinical trials consistently show improvements in:

Blood pressure: Significant reductions in systolic and diastolic BP
Lipid profile: Decreased LDL cholesterol, total cholesterol, triglycerides
Glycemic control: Reduced HbA1c, fasting glucose, and insulin levels
Liver health: Improvements in liver steatosis (fatty liver disease)
Cardiovascular markers: Reduced inflammation (C-reactive protein)

In participants with type 2 diabetes, the 12mg dose reduced HbA1c by 1.3-2.0% after 24 weeks, with average weight loss of 16.9%.

Research Gaps

What we know

Phase 2 and early Phase 3 data showing unprecedented weight loss efficacy
Safety profile consistent with other incretin therapies
Pharmaceutical-grade medication under FDA review process

What we’re still learning

Long-term safety beyond 68 weeks (ongoing trials will provide this)
Weight maintenance after stopping medication
Cardiovascular outcomes (likely being studied in dedicated trials)
Cost and insurance coverage (not yet determined)
FDA approval timeline (likely 2026-2027 based on trial completion)
Optimal maintenance dosing strategies

My Take on Retatrutide

Retatrutide sits in an entirely different category than BPC-157, TB-500, or even MT2. This is legitimate pharmaceutical development with the backing of a major pharmaceutical company, rigorous Phase 1-3 trials, and FDA oversight.

The efficacy data is genuinely remarkable. A 24-28% average weight loss in clinical trials is unprecedented for a medication—this rivals bariatric surgery outcomes. The fact that participants hadn’t plateaued by the end of studies suggests the full potential might be even greater.

What makes this different.

Actual human clinical trials: Not animal studies, not case series—large, randomized, placebo-controlled trials published in top-tier journals
Pharmaceutical oversight: FDA-regulated development process with rigorous safety monitoring
Quality control: Every dose is manufactured to pharmaceutical standards
Medical supervision: Being tested with proper dose escalation protocols and monitoring

Reality Check:

This isn’t available yet outside of clinical trials. You can’t order it online, and if you could, it wouldn’t be the real pharmaceutical-grade product. The “retatrutide” being sold by peptide vendors is completely unregulated and could be anything.

If FDA-approved (likely by 2026-2027), retatrutide will join semaglutide (Wegovy) and tirzepatide (Zepbound) as a prescription medication requiring medical supervision. The cost will likely be $1,000-1,500/month without insurance, similar to other GLP-1 medications.

Bottom Line:

Retatrutide represents the future of pharmaceutical obesity treatment—evidence-based, rigorously tested, and potentially transformative for people struggling with obesity. But it needs to go through the proper approval process and be used under medical supervision, not ordered from unregulated online sources.

The Bigger Picture

Here’s what becomes clear when you actually dig into peptide research:

Reality Check:

MT2: Has human trials showing it works for tanning, but long-term safety concerns remain unresolved
BPC-157: Promising in rats, virtually no human evidence despite 30+ years of research
GHK-Cu: Solid evidence for topical use, limited data for injectable applications
TB-500: Minimal human research, relies almost entirely on animal studies
Retatruetide: Robust Phase 2 human data showing unprecedented weight loss; currently in Phase 3 trials with a focus on heart rate and GI safety.

The gap between social media claims and actual research is enormous. Most peptide content focuses on mechanism and animal studies while glossing over the absence of human clinical trials.

Why the Research Gaps Matter

When compounds lack human trials, we don’t know:

Effective doses in humans (animal doses don’t translate directly)
Long-term safety profiles
Drug interactions
Who shouldn’t use them (contraindications)
Whether benefits outweigh risks

Add in the unregulated market—where product purity, dosing accuracy, and contamination are genuine concerns and you’re dealing with significant unknowns.

The Quality Control Problem

Research suggests 12-58% of peptide products sold online contain contaminants or incorrect dosing. You’re trusting that:

The powder contains what it claims
The dosing is accurate
No contaminants are present
Storage hasn’t degraded the product

These aren’t pharmaceutical-grade medications with FDA oversight. They’re research chemicals sold in a regulatory gray area.

Making Informed Decisions

I’m not here to tell you what to do. My goal is to give you the information to make your own educated decisions.

If you’re considering peptides:

Understand what the evidence actually shows (not just what influencers claim)
Know the difference between animal studies and human trials
Recognize the risks of unregulated products
Work with qualified medical professionals, not internet forums
Accept that you’re participating in an experiment on yourself

The research exists, but it’s not nearly as comprehensive as the marketing suggests.

Complete Reference List

Melanotan II (MT2): [1] Dorr RT, Lines R, Levine N, et al. Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Life Sci. 1996;58(20):1777-84. [2] Wessells H, Levine N, Hadley ME, Dorr R, Hruby V. Melanocortin receptor agonists, penile erection, and sexual motivation: human studies with Melanotan II. Int J Impot Res. 2000;12 Suppl 4:S74-9. [3] Brennan R, Wells JSG, Van Hout MC. Melanotan II User Experience: A Qualitative Study of Online Discussion Forums. Skin Health Dis. 2021;1(3):e42.

BPC-157: [4] Vasireddi N, Hahamyan H, Salata MJ, et al. Emerging Use of BPC-157 in Orthopaedic Sports Medicine: A Systematic Review. Orthop J Sports Med. 2025. [5] Lee E, Padgett B. Intra-Articular Injection of BPC 157 for Multiple Types of Knee Pain. Altern Ther Health Med. 2021;27(4):8-13. [6] Sikiric P, Rucman R, Turkovic B, et al. The Stable Gastric Pentadecapeptide BPC 157 Pleiotropic Beneficial Activity and Its Possible Relations with Neurotransmitter Activity. Curr Pharm Des. 2024. [7] FDA. Bulk Drug Substances Nominated for Use in Compounding Under Section 503B – Category 2. 2023.

GHK-Cu: [8] Pickart L, Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. Int J Mol Sci. 2018;19(7):1987. [9] Pickart L, Vasquez-Soltero JM, Margolina A. GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration. Biomed Res Int. 2015;2015:648108. [10] Dou Y, Lee A, Zhu L, Morton J, Ladiges W. The potential of GHK as an anti-aging peptide. Aging Pathobiol Ther. 2020;2(1):58-61.

TB-500: [11] Goldstein AL, Garaci E. Thymosin beta4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opin Biol Ther. 2012;12(1):37-51. [12] Crockford D. Thymosin Beta 4: Structure, Function, and Biological Properties Supporting Current and Future Clinical Applications. Ann N Y Acad Sci. 2007;1112:14-37.

Retatrutide: [13] Jastreboff AM, et al. Triple–Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. N Engl J Med. 2023;389(6):514-526. [14] Rosenstock J, et al. 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;402(10401):529-544. [16] Chao AM, et al. Perceived benefits of treatment for obesity with retatrutide: A qualitative study of patients in a phase 2 clinical trial. Diabetes Obes Metab. 2024. [17] Sampath Kumar A, et al. Efficacy and safety of retatrutide for obesity treatment: a systematic review and meta-analysis of randomized controlled trials. Ther Adv Endocrinol Metab. 2024. [15] Eli Lilly and Company. Lilly’s triple agonist, retatrutide, delivered weight loss of up to an average of 71.2 lbs in Phase 3 TRIUMPH-4 trial. Press release. December 11, 2024.