Body Composition

A GLP-1 receptor agonist FDA-approved for type 2 diabetes and chronic weight management, one of the most widely prescribed peptide drugs.

A dual GIP/GLP-1 receptor agonist FDA-approved for diabetes and weight management, producing the largest weight loss seen in clinical trials.

Recombinant human growth hormone — the full 191-amino-acid pituitary peptide, FDA-approved for a short list of specific deficiency and wasting indications and the subject of an enormous off-label market for anti-aging, performance, and body-composition use that runs far ahead of the evidence.

The 51-amino-acid two-chain pancreatic hormone discovered by Banting, Best, Macleod, and Collip at the University of Toronto in 1921-22 — the first life-saving peptide drug, the molecule whose primary structure Frederick Sanger determined in 1955 (the first protein ever sequenced), and the cornerstone of type 1 diabetes management plus advanced type 2 diabetes care for over a century.

A growth hormone-releasing hormone analog that was previously FDA-approved for diagnosing GH deficiency in children.

An FDA-approved GHRH analog used to reduce visceral fat in HIV-associated lipodystrophy.

A GLP-1 receptor agonist FDA-approved for diabetes (Victoza) and weight management (Saxenda), the predecessor to semaglutide.

A once-weekly GLP-1 receptor agonist FDA-approved for type 2 diabetes, with proven cardiovascular benefits and moderate weight loss effects.

The 167-amino-acid adipose hormone discovered in 1994 that was supposed to cure obesity — and did, for the handful of people born without it. For everyone else, the story turned out to be leptin resistance, not leptin deficiency, and the therapeutic lesson has been much harder than the biology.

The TGF-β superfamily protein that negatively regulates skeletal muscle mass — the biological target behind 'mighty mice,' Belgian Blue cattle, and an entire class of investigational inhibitor drugs that have underdelivered on the hype.

The circulating 'cellular stress' hormone of the TGF-β superfamily — the molecule that links metformin-induced weight loss, pregnancy-associated hyperemesis, and cancer cachexia through a single brainstem receptor (GFRAL). Not a self-administered peptide; the clinical programs are antibodies that block GDF-15, not supply it.

An investigational triple agonist (GIP/GLP-1/glucagon) from Eli Lilly. Not FDA-approved. In Phase III TRIUMPH-1 (NEJM, September 2026) the 12 mg dose produced 25.0% mean weight loss at 80 weeks, and TRIUMPH-2 (Lancet, September 2026) showed up to 18.8% in adults with obesity and type 2 diabetes. Lilly plans to file with the FDA in Q1 2027.

Foundayo (orforglipron) is Eli Lilly's oral small-molecule GLP-1 receptor agonist — FDA-approved April 1, 2026 for chronic weight management as the first oral non-peptide GLP-1 RA. Approved via the Commissioner's National Priority Voucher pilot in 50 days, the fastest NME approval since 2002. Once-daily tablet titrated 0.8 mg → 17.2 mg max; Phase 3 ATTAIN-1 showed 11.2% weight loss at 72 weeks.

An investigational dual glucagon/GLP-1 receptor agonist from Boehringer Ingelheim and Zealand Pharma. The Phase 3 SYNCHRONIZE-1 trial (le Roux et al., NEJM 7 June 2026) demonstrated ~12–13% mean weight loss at 76 weeks (treatment-regimen estimand) in adults with obesity without type 2 diabetes, and the companion SYNCHRONIZE-MASLD trial (Kaplan/Sanyal et al., Nature Medicine, same date) showed 84.2% of participants reduced liver fat by ≥30% at 48 weeks. SYNCHRONIZE-2 (Wharton et al., NEJM 1 October 2026) then showed -8.2% (3.6 mg) and -9.8% (6.0 mg) vs -3.9% placebo at 76 weeks in adults with obesity and type 2 diabetes (treatment-regimen estimand; up to 13.1% vs 3.1% on the efficacy estimand). FDA Fast Track (2021) and Breakthrough Therapy (2024) designations for MASH; not yet approved.

Amgen's first-in-class once-monthly bispecific antibody-peptide conjugate for obesity — GLP-1 receptor agonist + GIP receptor antagonist. Phase 2 NEJM showed mean weight loss of up to 16.2% at 52 weeks by intention-to-treat, or up to 19.9% if participants stayed on treatment, with no plateau.

A once-weekly amylin analogue from Novo Nordisk, developed with semaglutide as CagriSema (US decision expected Q4 2026) and, since late 2025, on its own in Phase 3.

Novo Nordisk's unimolecular dual GLP-1 and amylin receptor agonist (INN zenagamtide), advanced in both subcutaneous and oral formulations. Phase 1b/2a SC topline (Lancet 2025) showed up to 24.3% mean weight loss at 36 weeks. Phase 2 T2D peer-reviewed publications landed in Lancet August 15, 2026 (Mora et al., separate SC and oral papers): once-weekly SC (n=262) HbA1c treatment difference −0.77% to −1.56% and once-daily oral (n=186) HbA1c treatment difference −0.5% to −1.09% vs placebo at 36 weeks. The AMAZE Phase 3 program initiated in 2026 — AMAZE-1 (NCT07339423, 1,150 pts) started February 24, 2026 and AMAZE-12 (NCT07503210, ~600 pts, obesity maintenance) on April 21, 2026, with additional AMAZE trials in obesity+T2D, obesity+OA, and head-to-head versus semaglutide.

The first GLP-1 receptor agonist, originally derived from Gila monster venom, FDA-approved for type 2 diabetes.

An FDA-approved synthetic analogue of amylin used alongside insulin for diabetes, also studied for weight management.

An FDA-approved MC4R agonist for rare monogenic obesity (POMC/PCSK1/LEPR deficiency, Bardet-Biedl syndrome) and — as of March 2026 — acquired hypothalamic obesity in patients aged 4 and older.

A naturally occurring peptide hormone that raises blood sugar, FDA-approved as emergency treatment for severe hypoglycemia.

The 244-amino-acid adipocyte-secreted hormone discovered independently by four groups in 1995–1996 — unusual among adipokines in that its levels fall with obesity, not rise with it. High-adiponectin states are protective; low-adiponectin states track insulin resistance, type 2 diabetes, and cardiovascular disease. Direct therapeutic use is limited by its large multimeric structure, and the field's forward push is toward small-molecule AdipoR agonists like AdipoRon.

A GLP-1 receptor antagonist derived from the C-terminal fragment of exendin-4, investigational for post-bariatric hypoglycemia and congenital hyperinsulinism — pharmacologically the opposite of semaglutide and exenatide. The Phase 3 LUCIDITY trial met its primary endpoint on 18 August 2026 with a 55% reduction in Level 2 and Level 3 hypoglycemic events (p=0.000003), making avexitide the first GLP-1 receptor antagonist to succeed in Phase 3; Amylyx plans an NDA by the end of 2026.

Viking Therapeutics' dual GLP-1/GIP receptor agonist in late-stage development for obesity, available in subcutaneous weekly (Phase 3) and oral daily (Phase 2) formulations — positioned as a direct competitor to tirzepatide. A September 2026 maintenance study found that every-other-week or monthly dosing kept up to 97% and 90% of the weight lost on weekly induction, versus 61% on placebo.

Ascendis Pharma's once-weekly TransCon prodrug of human growth hormone, FDA-approved as SKYTROFA in August 2021 for pediatric growth hormone deficiency and expanded to adult GHD in July 2025. It releases unmodified somatropin from an inert carrier across a week, replacing seven daily injections with one — and in its pivotal pediatric trial it beat daily somatropin on growth, not merely matched it.

A growth hormone-releasing hormone analog that stimulates the pituitary gland to produce more growth hormone.

An orally active growth hormone secretagogue that mimics ghrelin to stimulate GH and IGF-1 release.

A modified growth hormone releasing hormone analog with a shorter half-life than DAC-conjugated CJC-1295, allowing more physiological GH pulsing.

The active isomer of clomiphene, a selective estrogen receptor modulator (SERM) that raises testosterone while preserving fertility. Not FDA-approved as a standalone drug, but widely available through compounding pharmacies.

A triple monoamine reuptake inhibitor (serotonin, noradrenaline, dopamine) that produced 9.2% average weight loss at 0.5 mg (vs 2.0% on placebo, both with diet) in a 24-week Phase 2 Lancet trial, and 10.6% at 1 mg. Not approved in any country, including Mexico.

The world's first approved dual GLP-1/glucagon receptor agonist, developed by Innovent Biologics (China) with Eli Lilly holding ex-China rights. Approved in China for obesity and type 2 diabetes. The Phase 3 GLORY-2 trial (JAMA 2026) reported 16.7% mean weight loss at 9 mg over 60 weeks; a US Phase 2 trial reported up to 18.1% at 16 mg over 32 weeks.

Zealand Pharma's long-acting amylin analog, partnered with Roche in a $5.3B deal. Phase 2b ZUPREME-1 showed up to 10.7% weight loss at 42 weeks with placebo-like GI tolerability apart from mild titration nausea — the 'tolerability play' in the amylin class. Phase 3 ZUPREME began September 2026.

Roche/Genentech's next-generation dual GLP-1/GIP receptor agonist (INN: enicepatide, assigned 2026). Phase 2 showed 22.5% placebo-adjusted weight loss at 48 weeks — competitive with retatrutide. Phase 3 ENITH program initiated Q1 2026 with two pivotal trials. A 48-week Phase 2 in type 2 diabetes (September 2026) showed HbA1c down 2.65 points and 15.5% weight loss at 24 mg.

An endogenous 36-amino-acid gut hormone released by intestinal L-cells after meals; its active fragment PYY(3-36) is a Y2-receptor-selective satiety signal.

Altimmune's investigational unimolecular GLP-1 / glucagon receptor dual agonist peptide with what Altimmune describes as a balanced 1:1 receptor activity ratio — among the most glucagon-weighted dual agonists in clinical development for MASH. The Phase 2b IMPACT trial (n=212, biopsy-confirmed MASH F2/F3) reported MASH resolution rates of 58% (1.2 mg) and 52% (1.8 mg) versus 20% on placebo at 24 weeks (Lancet 2025), with 48-week non-invasive endpoints presented at EASL 2026 (Barcelona, May 27–30): ELF down 0.58, liver stiffness −3.97 kPa, MRI liver fat content −54.7%, and weight loss 7.5% at the 1.8 mg dose. The 48-week abstract received the Best of EASL 2026 designation, and a separate EASL late-breaking poster reported qFibrosis-measured fibrosis regression at 24 weeks (68.6%/54.5%/29.6% across 1.2 mg/1.8 mg/placebo) — closing a notable gap with the negative 24-week NASH-CRN biopsy fibrosis endpoint. FDA Fast Track and Breakthrough Therapy (January 2026) designations for MASH. The Phase 3 PERFORMA trial (NCT07795164, ~1,800 patients) began in July 2026, and the Phase 2 RECLAIM trial in alcohol use disorder read out positive in July 2026.

Hanmi's once-weekly GLP-1 receptor agonist, an exendin-4 analog linked to an antibody Fc fragment. Under Sanofi it cut major cardiovascular events by 27% in the 4,076-person AMPLITUDE-O trial; back with Hanmi, a Korean obesity Phase 3 showed 9.75% weight loss at 40 weeks vs 0.95% on placebo. Under Korean MFDS review as of October 2026.

Gan & Lee's GLP-1 receptor agonist built for one injection every two weeks. In China's Phase 3 GRADUAL-1 trial, weight fell 15.12% (24 mg) and 18.54% (48 mg) over 52 weeks vs 1.11% on placebo; China's regulator accepted its marketing application in September 2026 and Menarini holds European rights. It is not approved anywhere yet.

A selective growth hormone secretagogue that, in animal studies, released GH without the ACTH and cortisol rise seen with older GHRPs.

A synthetic growth hormone secretagogue that stimulates natural GH release, studied for body composition, recovery, and anti-aging.

A synthetic growth hormone secretagogue known for potent GH release and significant appetite stimulation through ghrelin receptor activation.

A naturally occurring dipeptide concentrated in muscle and brain tissue, studied for anti-aging, cognitive support, and exercise performance.

The original 'exercise in a pill' — an AMPK activator that increased running endurance by 44% in sedentary mice. Banned by WADA since 2009. Studied for metabolic syndrome, diabetes, and cardioprotection.

An endogenous 37-amino-acid gut hormone and natural dual agonist at the GLP-1 and glucagon receptors — the physiologic template behind the dual-agonist obesity drug class (cotadutide, survodutide, mazdutide).

Acceleron Pharma's soluble ActRIIB-Fc decoy receptor — a myostatin/activin ligand trap that produced striking muscle-mass signals in healthy volunteers and Duchenne boys before its Phase 2 DMD program was halted in 2011 over epistaxis and telangiectasia attributed to broad TGF-β pathway blockade.

An endogenous peptide hormone and ligand of the APJ receptor with positive inotropic, vasodilatory, and insulin-sensitizing effects — heavily studied as a heart-failure target but not available as an approved therapy, with small-molecule APJ agonists now advancing through early clinical trials.

MBX Biosciences' investigational once-weekly GLP-1 receptor antagonist for post-bariatric hypoglycemia — a sustained-action competitor to avexitide with a substantially longer dosing interval.

A modified fragment of human growth hormone studied specifically for fat metabolism without the growth-promoting effects of full GH.

An investigational once-weekly dual GLP-1/GIP receptor agonist from Jiangsu Hengrui, with ex-Greater China rights held by Kailera Therapeutics. Phase 3 in China produced up to 19.2% weight loss at 48 weeks; the global Phase 3 KaiNETIC program finished enrolling about 4,900 participants in September 2026, with topline data expected in mid-2028.

Eli Lilly's once-weekly selective amylin receptor agonist. Phase 2 trials showed up to 20% weight loss at 48 weeks with favorable tolerability. Phase 3 enrollment began late 2025, and the EloraTZP combination with tirzepatide showed up to 23.3% weight loss in a Phase 2b in obesity plus type 2 diabetes.

Berobenatide (PF-08653944, originally Metsera's MET-097i) is Pfizer's investigational ultra-long-acting, fully-biased GLP-1 receptor agonist designed for once-monthly injection — Phase 2b VESPER-3 showed up to 12.3% placebo-adjusted weight loss at 28 weeks with weekly titration followed by monthly doses, and a small open-label VESPER-1 extension group lost 15.9% over 32 weeks; Pfizer plans 10 Phase 3 trials and is targeting first approvals beginning in 2028.

Ascletis Pharma's investigational small-molecule biased GLP-1 receptor agonist for obesity — an oral pathway competing with orforglipron and oral semaglutide, with cAMP-biased signaling that may reduce GI side effects relative to balanced GLP-1R agonists.

MetaVia Inc.'s once-weekly oxyntomodulin-analog dual GLP-1R/GCGR agonist, in-licensed from Dong-A ST. An 8-week 48 mg Phase 1 cohort showed −9.1% body weight at Day 54 and lower liver stiffness and liver fat on FibroScan in obesity. The Phase 1 Part 3 titration study reports 16-week data in Q4 2026 and 24-week data in Q1 2027.

Hanmi Pharmaceutical's once-weekly CRFR2-selective urocortin-2 analog for obesity — a deliberately non-incretin approach designed to reduce fat mass while preserving or increasing lean mass, in contrast to the roughly one-quarter of weight lost as lean tissue on GLP-1 monotherapy. Licensed to Genentech in August 2026 for $190 million upfront within a deal worth up to about $2.3 billion. Still Phase 1, with no human data published.

AbbVie's long-acting amylin analog, licensed from Denmark's Gubra in 2025 for $350 million upfront. Its half-life of about 11 days let Phase 1 test weekly, every-other-week and monthly injections: weight fell 7.8–9.8% at 12 weeks on weekly dosing and 7.9% at 13 weeks on monthly dosing, vs about 0.3% on placebo. A 360-person Phase 2 began in August 2026.

A mitochondria-derived peptide that regulates metabolic homeostasis and has been called an 'exercise mimetic.'

An exercise-induced myokine that promotes browning of white adipose tissue, enhances metabolism, and shows neuroprotective effects — though bioavailability and clinical translation remain challenging.

A synthetic tetrapeptide bioregulator (Lys-Glu-Asp-Trp) from the Khavinson system, studied for pancreatic function, glucose metabolism, and age-related type 2 diabetes.

An experimental fat-targeting peptide that selectively destroys blood vessels feeding white adipose tissue. Produced dramatic fat loss in primate studies but was discontinued due to kidney toxicity.

A synthetic exercise mimetic that activates estrogen-related receptors (ERRs) to replicate the molecular effects of aerobic exercise — increasing endurance, fat oxidation, and mitochondrial function in mice without physical activity. It has never been tested in a human trial, and WADA banned it by name from 2027.

A selective NNMT inhibitor that reduces fat mass by boosting NAD+ and cellular energy expenditure — without affecting appetite. In mice, 11 days of treatment produced 5% weight loss and 35% reduction in white adipose tissue.

A 14-amino-acid peptide hormone that activates galanin receptors 2 and 3 — lower in obesity and type 2 diabetes, investigated as a potential metabolic therapeutic and biomarker but still without any approved product or clinical trial program.

A 12-amino-acid peptide cleaved from the BRINP2 protein that activates appetite-regulating neurons in the hypothalamus (not POMC neurons) through a pathway separate from GLP-1, leptin and MC4R. Identified by Stanford's Svensson lab with a computational prohormone-cleavage prediction tool and published in Nature (2025). Preclinical only — no human trial has been registered as of October 2026.

The original synthetic growth hormone-releasing peptide developed by Cyril Bowers and Frank Momany in the late 1970s through structural optimization of Met-enkephalin — the historical seed of the GHRP class that gave rise to GHRP-2, GHRP-6, hexarelin, and ipamorelin, and the discovery program that eventually led to the identification of the ghrelin receptor (GHSR1a).

An endogenous TGF-β superfamily peptide closely related to myostatin (~90% identity in mature domain), launched into mainstream attention by Loffredo and Wagers' 2013 Cell paper claiming circulating GDF-11 declines with age and reverses cardiac hypertrophy in aged mice — a rejuvenation story that has been substantially complicated by Egerman, Glass, and others' contradicting work showing antibody specificity issues, GDF-11 increases (not decreases) with age in some populations, and direct GDF-11 administration may worsen rather than improve outcomes.

The N-terminal propeptide domain of myostatin that remains non-covalently bound to mature myostatin in latent extracellular complexes — characterized by Hill, Lee, and colleagues (JBC 2002, Mol Endocrinol 2003) as one of the principal endogenous inhibitors of myostatin signaling, alongside follistatin and the GASP-1/GASP-2 follistatin-related proteins. Studied as a research-tier myostatin antagonism strategy in muscular dystrophy, sarcopenia, and muscle-wasting models.

MBX Biosciences' investigational once-monthly GLP-1/GIP dual agonist prodrug for obesity — an extended-action approach that would substantially reduce dosing frequency versus weekly GLP-1/GIP agents like tirzepatide.

MBX Biosciences' investigational amycretin prodrug for obesity — extended-action chemistry intended to provide amylin and GLP-1 dual receptor activation with reduced dosing frequency compared to amycretin itself.

Ascletis Pharma's investigational GLP-1/GIP dual receptor agonist for obesity and type 2 diabetes — the company's tirzepatide-class candidate, in early clinical development.

Ascletis Pharma's investigational amylin analog for obesity — competing with cagrilintide, petrelintide, and eloralintide in the amylin agonist class.

A GLP-1/GIP/FGF21 triple-agonist Fc-fusion protein from Shanghai Minwei Biotechnology, in Chinese Phase Ib and Phase II trials for obesity — including a cohort specifically enrolling semaglutide-intolerant patients. Licensed ex-Greater China to Denmark's Sidera Bio in October 2025. The mechanism is genuinely interesting; the public evidence is one sponsor conference abstract and no human results at all.