Metabolic Peptides

Semaglutide (GLP-1 agonist)

Semaglutide is a long-acting GLP-1 receptor agonist approved by the FDA for type 2 diabetes (Ozempic), chronic weight management plus CV risk reduction in obesity (Wegovy), and oral type 2 diabetes (Rybelsus). It works by enhancing glucose-dependent insulin secretion, suppressing glucagon, delaying gastric emptying, and reducing appetite through central GLP-1 receptor activation. Per the FDA Wegovy label, titrate every 4 weeks: 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg weekly. Ozempic (T2DM) maxes at 2.0 mg weekly. Carries a boxed warning for medullary thyroid carcinoma (MTC) and MEN 2. HbA1c, fasting glucose, insulin, a full lipid panel, and liver enzymes are the standard biomarkers researchers track, with CRP sometimes added to monitor inflammatory changes.

Tirzepatide (GIP/GLP-1 dual receptor agonist — Mounjaro, Zepbound)

Tirzepatide is a dual GIP + GLP-1 receptor co-agonist FDA-approved as Mounjaro (type 2 diabetes, 2022) and Zepbound (chronic weight management, 2023; moderate-to-severe obstructive sleep apnea with obesity, 2024). Weekly SubQ dosing titrates 2.5 → 5 → 7.5 → 10 → 12.5 → 15 mg, with 4-week intervals between increases per FDA label. In SURPASS-2 it outperformed semaglutide 1 mg for A1C and weight; SURMOUNT-1 showed up to ~20.9% mean body-weight reduction at 15 mg over 72 weeks. Carries a BOXED WARNING for thyroid C-cell tumors — contraindicated with personal/family history of MTC or MEN 2. Common AEs are GI (nausea, vomiting, diarrhea); serious risks include pancreatitis, gallbladder disease, hypoglycemia when combined with insulin or sulfonylureas, AKI from volume depletion, and diabetic retinopathy complications. HbA1c, fasting glucose, insulin, lipid panel, CRP, and body composition are the standard biomarkers researchers track.

Retatrutide (LY3437943 — GLP-1/GIP/Glucagon triple agonist)

Retatrutide (LY3437943) is Eli Lilly's investigational triple-agonist peptide activating GLP-1, GIP, and glucagon receptors in parallel, and it remains research-only — it is NOT FDA-approved as of April 2026. The glucagon-receptor arm is what distinguishes it from tirzepatide: glucagon agonism drives thermogenesis, hepatic fat mobilization, and energy expenditure on top of the appetite-suppression and insulin-sensitizing effects of GLP-1/GIP. Published Phase 2 data showed approximately 24% mean body weight loss at 48 weeks on 12 mg weekly (Jastreboff, NEJM 2023), with parallel Phase 2 programs in T2D (Rosenstock, Lancet 2023) and MASLD (Sanyal, Nat Med 2024). The Phase 3 TRIUMPH program is ongoing with anticipated NDA filing in 2026. Phase 3 trials titrate from 2 mg to 12 mg weekly subcutaneously; the compound has a half-life of roughly 6 days, supporting once-weekly dosing. Researchers monitor HbA1c, fasting glucose, insulin, full lipid panel, liver enzymes (ALT/AST), body composition, and especially heart rate — a consistent ~7 bpm elevation is a class effect that warrants monitoring.

Mitochondrial Open reading frame of the Twelve S rRNA type-c

MOTS-c is a 16 amino acid mitochondrial-derived peptide (sequence MRWQEMGYIFYPRKLR) encoded within the mitochondrial 12S rRNA — reported by Lee, Cohen, and colleagues at USC in 2015. Preclinical research focuses on AMPK activation in skeletal muscle, increased glucose uptake, and fatty acid oxidation. Human clinical data are limited to a single Phase 1a/1b study of the modified analog CB4211 (CohBar), which reported acceptable tolerability but mixed exploratory readouts; CohBar divested from the program and wound down in 2023. Grey-market protocols commonly use ~10mg subcutaneously 2–3 times per week in 4–8 week cycles, but this dosing is not clinically validated. Fasting glucose, insulin, HbA1c, lactate, and CRP are the biomarkers typically tracked.

Anti-Obesity Drug 9604

AOD-9604 is a 16-amino-acid synthetic peptide corresponding to the C-terminal fragment of human growth hormone (residues 177-191) with an additional N-terminal tyrosine. Developed by Metabolic Pharmaceuticals (Australia) to isolate a purported 'lipolytic' activity of GH without GH-receptor-mediated growth or diabetogenic effects. AOD-9604 is NOT FDA-approved for any indication; controlled human trials for obesity did not demonstrate clinically meaningful weight loss, and obesity development was terminated in 2007.

5-Amino-1-methylquinolinium

5-Amino-1MQ is a small heterocyclic molecule (not a peptide) that acts as a selective, membrane-permeable inhibitor of nicotinamide N-methyltransferase (NNMT). It is under preclinical investigation for obesity and non-alcoholic fatty liver disease. It is not FDA-approved and has not completed human clinical trials; it is commonly tracked alongside peptides because grey-market vendors sell it for metabolic protocols.

Victoza

Liraglutide is an FDA-approved GLP-1 receptor agonist marketed as Victoza (type 2 diabetes, approved 2010) and Saxenda (chronic weight management, approved 2014). It was the first GLP-1 analog approved for obesity and carries an FDA boxed warning for the risk of thyroid C-cell tumors. Pediatric indications include type 2 diabetes in patients ≥10 years (Victoza) and obesity in patients ≥12 years with BMI ≥95th percentile (Saxenda).

Nicotinamide Adenine Dinucleotide

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme present in all living cells, not a peptide. It is classified here alongside peptides for user convenience in the anti-aging / metabolic category. NAD+ plays a central role in cellular energy metabolism and redox reactions and is studied for its involvement in mitochondrial function, DNA-damage signaling via sirtuins and PARPs, and age-associated metabolic decline. IV NAD+ is not FDA-approved for any clinical indication; it is administered off-label through compounding pharmacies and functional-medicine clinics with limited rigorous outcome data.

NN9838

Cagrilintide is a long-acting acylated amylin analog developed by Novo Nordisk. It is investigational and not FDA-approved; Novo Nordisk's lead development path is the CagriSema co-formulation with semaglutide for weight management. Monotherapy cagrilintide was evaluated in Phase 2 but was deprioritized in favor of the combination.

FOXO4-D-Retro-Inverso

FOXO4-DRI is a D-retro-inverso peptide designed to disrupt the FOXO4-p53 interaction in senescent cells. It is studied as a senolytic agent that selectively induces apoptosis in senescent cells while sparing normal cells.

Pancragen

A short synthetic peptide bioregulator (Lys-Glu-Asp-Trp) from the Khavinson family, marketed for pancreatic/metabolic support. Evidence is largely Russian-language and preclinical.

IBI362

Mazdutide is a dual GLP-1 / glucagon receptor agonist licensed from Eli Lilly to Innovent Biologics for Greater China. Approved by China's NMPA in June 2025 for chronic weight management and in September 2025 for glycemic control in type 2 diabetes; NOT FDA-approved in the US.

BI 456906

Survodutide is a dual GLP-1 / glucagon receptor agonist co-developed by Boehringer Ingelheim and Zealand Pharma. NOT FDA-approved; received FDA Breakthrough Therapy Designation in 2024 for non-cirrhotic MASH with moderate/advanced fibrosis. Phase 3 ongoing (SYNCHRONIZE in obesity/T2DM; LIVERAGE and LIVERAGE-Cirrhosis in MASH).

LY3502970

Orforglipron (brand name Foundayo) is Eli Lilly's oral non-peptide small-molecule GLP-1 receptor agonist. Unlike oral semaglutide (Rybelsus), it does not require the SNAC absorption enhancer or fasting/water restrictions — it can be taken any time of day. Not a peptide.

NS2330

Tesofensine is a small-molecule triple monoamine reuptake inhibitor (serotonin, norepinephrine, dopamine) — NOT a peptide. Originally developed by NeuroSearch for Parkinson's and Alzheimer's disease (which it failed to benefit) and repositioned for obesity by Saniona. Not FDA-approved in the US.

FTPP

Adipotide (FTPP) is a chimeric peptidomimetic developed in the Arap/Pasqualini lab (originally at MD Anderson) that couples a 9-residue homing motif (CKGGRAKDC) — isolated by in vivo phage display as a ligand for prohibitin on white-adipose-tissue vasculature — to the D-amino-acid pro-apoptotic domain D(KLAKLAK)2. It is an experimental research compound, NOT FDA-approved for any indication. A clinical-development program in prostate-cancer-associated obesity reached early-phase testing and was ultimately discontinued.

cagrisema

CagriSema is Novo Nordisk's investigational once-weekly fixed-dose co-formulation of cagrilintide 2.4 mg (long-acting amylin analog) with semaglutide 2.4 mg (GLP-1 receptor agonist) for chronic weight management. Unlike the other grey-market blends, it has a proper Phase 3 clinical program. Novo Nordisk filed an FDA NDA in December 2025; as of April 2026 it is under FDA review and not yet approved.