Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
The landscape of peptide-based weight loss compounds has expanded rapidly. From FDA-approved GLP-1 agonists like Semaglutide and Tirzepatide to research compounds like Retatrutide and AOD-9604, there are now multiple mechanisms of action being studied for fat loss. This guide covers seven of the most discussed compounds, their mechanisms, research dosing, and what the clinical data actually shows — without hype or medical advice.
| Peptide | Mechanism | Typical Research Dose | Status |
|---|---|---|---|
| Semaglutide | GLP-1 agonist | 0.25–2.4 mg/week (SubQ) | FDA-Approved |
| Tirzepatide | Dual GIP/GLP-1 agonist | 2.5–15 mg/week | FDA-Approved |
| Retatrutide | Triple GLP-1/GIP/glucagon agonist | 1–12 mg/week | Phase 3 Trials |
| AOD-9604 | GH fragment (lipolytic) | 250–500 mcg/day | Research |
| MOTS-c | Mitochondrial peptide (AMPK activator) | 5–10 mg, 3–5x/week | Research |
| Tesamorelin | GHRH analog | 2 mg/day | FDA-Approved |
| 5-Amino-1MQ | NNMT inhibitor (small molecule) | 50–100 mg/day (oral) | Research |
Also known as: Ozempic, Wegovy, Rybelsus
Semaglutide is an FDA-approved GLP-1 receptor agonist used to treat type 2 diabetes (Ozempic) and chronic weight management (Wegovy). It has become one of the most widely prescribed medications for obesity due to its significant weight-loss efficacy in clinical trials.
Semaglutide mimics the incretin hormone GLP-1, binding to GLP-1 receptors in the pancreas to stimulate insulin secretion and suppress glucagon release. It also acts on the hypothalamus to reduce appetite and slow gastric emptying, leading to reduced caloric intake.
SubQ: 0.25–2.4 mg once weekly, following a titration schedule (0.25 mg for 4 weeks, then 0.5 mg, escalating to target dose). Oral: 3–14 mg once daily, taken on an empty stomach with no more than 4 oz of water.
The STEP clinical trial program demonstrated average weight loss of 15–17% body weight over 68 weeks. The SELECT trial showed a 20% reduction in major adverse cardiovascular events in obese participants without diabetes. Oral semaglutide (Rybelsus) is also FDA-approved for type 2 diabetes.
Contraindicated in individuals with personal or family history of medullary thyroid carcinoma or MEN 2. Common side effects include nausea, vomiting, diarrhea, and constipation. Dose titration over several weeks helps mitigate GI side effects. Weight regain after discontinuation is well-documented in the literature.
Also known as: Mounjaro, Zepbound
Tirzepatide is an FDA-approved dual GIP/GLP-1 receptor agonist for type 2 diabetes (Mounjaro) and chronic weight management (Zepbound). It represents a new class of dual-incretin therapy with superior weight-loss efficacy compared to single-agonist approaches.
Tirzepatide simultaneously activates GIP and GLP-1 receptors, producing complementary metabolic effects. GIP receptor activation enhances insulin sensitivity and may improve fat metabolism, while GLP-1 receptor activation reduces appetite and slows gastric emptying.
2.5–15 mg subcutaneously once weekly. Titration schedule: 2.5 mg for 4 weeks, then 5 mg for 4 weeks, then increasing by 2.5 mg every 4 weeks to a maximum of 15 mg. Injected in the abdomen, thigh, or upper arm.
The SURMOUNT-1 trial demonstrated average weight loss of 22.5% at the highest dose (15 mg) over 72 weeks, surpassing semaglutide results. HbA1c reductions were also superior in head-to-head trials (SURPASS-2). Cardiovascular outcome trials are ongoing.
Same thyroid carcinoma and MEN 2 contraindications as semaglutide. Nausea and GI side effects are common during dose escalation but tend to diminish over time. The dual-agonist mechanism may explain the enhanced efficacy compared to GLP-1-only compounds.
Also known as: LY3437943, Triple G
Retatrutide is a novel triple-agonist peptide targeting GLP-1, GIP, and glucagon receptors simultaneously. Developed by Eli Lilly, it is currently in Phase 3 clinical trials for obesity and type 2 diabetes and has demonstrated the highest weight loss of any anti-obesity medication tested to date.
Retatrutide simultaneously activates three receptors: GLP-1R (appetite suppression, insulin secretion), GIPR (insulin sensitivity, fat metabolism), and the glucagon receptor (energy expenditure, hepatic fat reduction). The glucagon receptor component is unique among this class and promotes thermogenesis and fatty acid oxidation beyond what dual agonists achieve.
1–12 mg subcutaneously once weekly in Phase 2 trials. Titration schedule similar to other GLP-1 agonists, increasing dose every 4 weeks to minimize GI side effects. Not yet approved — all dosing data comes from clinical trial protocols.
The Phase 2 trial demonstrated up to 24.2% body weight loss at 48 weeks at the highest dose (12 mg), exceeding results of both semaglutide and tirzepatide in comparable timeframes. Significant reductions in hepatic steatosis (fatty liver) were also observed. Phase 3 trial results are expected in 2025–2026.
Not yet FDA-approved. All data comes from Phase 2 trials with limited participant numbers. Side effect profile is similar to other incretin-based therapies: nausea, diarrhea, decreased appetite, constipation, and increased heart rate. The glucagon receptor component raises theoretical concerns about hepatic glucose output that are being monitored in ongoing trials.
Also known as: Anti-Obesity Drug 9604, HGH Fragment 176-191
AOD-9604 is a modified fragment of human growth hormone (amino acids 177-191) originally developed as an anti-obesity agent. It stimulates lipolysis and inhibits lipogenesis without the diabetogenic or growth-promoting effects of full HGH.
AOD-9604 mimics the lipolytic action of natural growth hormone by interacting with the beta-3 adrenergic receptor pathway in adipose tissue. It stimulates the breakdown of stored triglycerides and inhibits the formation of new fat cells without binding to the GH receptor or affecting IGF-1 levels. This selectivity is what distinguishes it from full-length HGH.
250–500 mcg subcutaneously once daily. Typically administered on an empty stomach in the morning. Research protocols commonly use 12-week cycles.
Phase 2 clinical trials showed modest weight loss in obese subjects over 12 weeks. Preclinical studies demonstrate significant fat reduction without affecting lean mass or glucose homeostasis. It has FDA GRAS (Generally Recognized As Safe) status for food use. The magnitude of weight loss in trials is notably less than GLP-1 agonists.
Not FDA-approved for weight loss. Human trial data is more limited compared to GLP-1 agonists. Side effects are generally mild: injection site redness, headache, mild nausea. Contraindicated in active cancer, pregnancy, and uncontrolled diabetes.
Also known as: Mitochondrial ORF of the Twelve S rRNA type-c
MOTS-c is a mitochondrial-derived peptide encoded by the 12S rRNA gene. It is studied as a metabolic regulator that improves insulin sensitivity, promotes fat oxidation, and enhances exercise capacity. It has been called an “exercise mimetic peptide” due to its effects on cellular energy metabolism.
MOTS-c activates AMPK (AMP-activated protein kinase) via inhibition of the folate-methionine cycle, shifting cellular metabolism toward fat oxidation and improving glucose uptake independent of insulin. It also promotes skeletal muscle glucose utilization and prevents diet-induced obesity in animal models.
5–10 mg subcutaneously, 3–5 times per week. Often cycled 4–8 weeks. Some research protocols time administration on training days for potential synergistic effects with exercise.
Preclinical studies in mice demonstrate improved insulin sensitivity, prevention of age-related metabolic dysfunction, and enhanced exercise capacity. Endogenous MOTS-c levels decline with age and correlate with metabolic fitness. Human clinical data is limited but emerging. The compound shows particular promise as a metabolic health optimizer rather than a primary weight-loss agent.
Most evidence is preclinical (animal studies). Human trials are limited. AMPK activation may affect tumor metabolism variably, making active cancer a contraindication. Side effects are generally mild: injection site reactions, mild nausea, temporary fatigue, and headache.
Also known as: Egrifta, TH9507
Tesamorelin is an FDA-approved synthetic analog of GHRH (growth hormone-releasing hormone) used to reduce excess abdominal fat in HIV-associated lipodystrophy. It is the only GHRH analog with current FDA approval and is increasingly studied in anti-aging and metabolic health contexts.
Tesamorelin binds to GHRH receptors on the anterior pituitary, stimulating the synthesis and release of endogenous growth hormone. The trans-3-hexenoic acid modification enhances stability and receptor binding affinity compared to native GHRH. Unlike exogenous HGH, it works through the body’s natural GH production pathway.
2 mg subcutaneously once daily. The FDA-approved dose for HIV-associated lipodystrophy is 2 mg daily, administered in the abdomen on an empty stomach. Effects may reverse upon discontinuation.
FDA-approved in 2010 based on Phase 3 trials demonstrating a 15% reduction in visceral adipose tissue in HIV-associated lipodystrophy. Studies also show improvements in trunk fat, lipid profiles, and IGF-1 levels. Cognitive benefits have been observed in APOE4-positive patients at risk for Alzheimer’s disease.
Primarily targets visceral (abdominal) fat rather than overall body weight — this makes it different from GLP-1 agonists. Side effects include injection site reactions, joint pain, peripheral edema, and elevated IGF-1 levels. Contraindicated in active malignancy and disruption of the hypothalamic-pituitary axis.
Small molecule — not technically a peptide
5-Amino-1MQ is a small molecule NNMT (nicotinamide N-methyltransferase) inhibitor studied for its anti-obesity and metabolic effects. While not a peptide, it is commonly discussed in the peptide space due to its use in metabolic optimization protocols. It reduces fat cell size and promotes energy expenditure.
5-Amino-1MQ inhibits NNMT, an enzyme that methylates nicotinamide and depletes the SAM (S-adenosylmethionine) methyl donor pool. NNMT inhibition increases intracellular NAD+ levels, activates the SIRT1 pathway, and promotes fat oxidation. It shrinks fat cells by increasing cellular energy expenditure and reducing lipogenesis.
50–100 mg orally once daily. Typically taken in the morning. Research protocols commonly use 8–12 week cycles. This is one of the few metabolic compounds in this space that is taken orally rather than injected.
Preclinical studies in diet-induced obese mice show reduced body weight, decreased adipocyte size, and improved cholesterol profiles without changes in food intake. The compound reverses diet-induced obesity through enhanced cellular metabolism. Human clinical trials are not yet published.
No published human clinical trial data. All evidence is preclinical. Side effects reported anecdotally include headache, mild nausea, and GI discomfort. Contraindicated in hepatic impairment and concurrent use of medications metabolized via methylation pathways. Should not be used during pregnancy or breastfeeding.
These seven compounds fall into distinct mechanistic categories. The right choice depends entirely on the research context and should always involve a qualified healthcare provider.
GLP-1 Receptor Agonists
Semaglutide, Tirzepatide, Retatrutide
These work primarily through appetite suppression and metabolic signaling in the brain and gut. They produce the most significant overall weight loss in clinical trials. Tirzepatide adds GIP receptor activation; Retatrutide adds both GIP and glucagon receptor activation. All require dose titration and are administered by weekly injection. GI side effects are the primary concern.
Growth Hormone Fragments & Analogs
AOD-9604, Tesamorelin
These target fat tissue more directly through growth hormone pathways. AOD-9604 is a GH fragment that stimulates lipolysis without affecting IGF-1. Tesamorelin stimulates endogenous GH release and has FDA approval for reducing visceral fat. The magnitude of overall weight loss is generally less than GLP-1 agonists, but the mechanism preferentially targets fat tissue.
Metabolic Modulators
MOTS-c, 5-Amino-1MQ
These compounds operate at the cellular metabolism level. MOTS-c activates AMPK to shift metabolism toward fat oxidation. 5-Amino-1MQ inhibits NNMT to boost NAD+ and cellular energy expenditure. Both are primarily supported by preclinical data and are best understood as metabolic optimizers rather than primary weight-loss agents. They may complement other approaches but should not be considered first-line options based on current evidence.
Based on clinical trial data, Retatrutide has demonstrated the highest weight loss in trials (up to 24.2% body weight at 48 weeks), followed by Tirzepatide (22.5% at 72 weeks) and Semaglutide (15-17% at 68 weeks). However, Retatrutide is still in Phase 3 trials and is not yet FDA-approved. Among approved options, Tirzepatide (Zepbound) has shown the greatest efficacy.
GLP-1 agonists (Semaglutide, Tirzepatide, Retatrutide) primarily reduce appetite and caloric intake through brain signaling pathways, leading to significant overall weight loss. GH-related peptides like AOD-9604 and Tesamorelin target fat tissue more directly — stimulating lipolysis (fat breakdown) or reducing visceral fat through growth hormone pathways. The mechanisms are fundamentally different and serve different goals.
FDA-approved peptides like Semaglutide, Tirzepatide, and Tesamorelin have undergone extensive clinical trials establishing their safety profiles. Common side effects include gastrointestinal issues (nausea, diarrhea). Research-only compounds like AOD-9604, MOTS-c, and 5-Amino-1MQ have more limited human safety data. All compounds carry contraindications and potential side effects. Consult a licensed healthcare provider before using any peptide.
Some research protocols combine peptides with different mechanisms — for example, a GLP-1 agonist with a GH secretagogue. However, combining multiple compounds increases complexity and the potential for interactions. Any combination protocol should only be undertaken under the supervision of a qualified healthcare provider.
GLP-1 agonists like Semaglutide and Tirzepatide typically require dose titration over several weeks. Appetite reduction is often noticed within the first few weeks, but significant weight loss accumulates over months. Clinical trials measured outcomes at 48-72 weeks. AOD-9604 studies used 12-week cycles. Results vary significantly between individuals.
Research suggests that weight regain is common after discontinuing GLP-1 agonists. The STEP 1 trial extension found that participants regained approximately two-thirds of lost weight within one year of stopping Semaglutide. This is an active area of research, and strategies for maintaining weight loss post-treatment are being studied.
Semaglutide is a GLP-1 receptor agonist (single target), while Tirzepatide is a dual GIP/GLP-1 receptor agonist (two targets). In head-to-head trials, Tirzepatide produced greater weight loss and HbA1c reductions. Tirzepatide is available as Mounjaro (diabetes) and Zepbound (weight management). Semaglutide is available as Ozempic (diabetes) and Wegovy (weight management).
No. 5-Amino-1MQ is a small molecule NNMT inhibitor, not a peptide. However, it is commonly discussed alongside peptides in the metabolic optimization space because it is frequently used in similar research contexts. It is taken orally rather than injected.
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This guide is for educational purposes only. It is not medical advice. Consult a licensed healthcare provider before using any peptide or metabolic compound.
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