What researchers are studying each one for, and a grade for how strong the evidence is behind each use.
Weight & metabolism
A once-weekly GLP-1 receptor agonist, studied in large phase 3 and cardiovascular outcome trials.
What it's being studied for
- AChronic weight management
- ABlood sugar control in type 2 diabetes
- ACardiovascular event reduction (established CVD + overweight)
Weight & metabolism
A dual GIP/GLP-1 receptor agonist. Activates two appetite-hormone receptors; produced more weight loss than semaglutide head-to-head.
What it's being studied for
- AChronic weight management
- ABlood sugar control in type 2 diabetes
- AObstructive sleep apnea with obesity
Retatrutide
In clinical trials
LY3437943 · Triple G agonist
Weight & metabolism
Lilly's once-weekly triple-hormone agonist. Phase 3 trials report about 20% average weight loss; not yet FDA-approved.
What it's being studied for
- AWeight reduction in obesity
- BLiver fat reduction (MASLD)
- CCardiovascular event reduction
Body Protection Compound-157 · PL 14736
Recovery research
A 15-amino-acid peptide studied mainly in rats for tendon, muscle and gut repair. One small, uncontrolled human case series has been published.
What it's being studied for
- DTendon, ligament and muscle repair
- DKnee pain (intra-articular)
- DGut lining and inflammatory bowel conditions
- EGeneral anti-aging or whole-body claims
Thymosin beta-4 fragment
Recovery research
A synthetic fragment of thymosin beta-4, a tissue-repair protein. The parent protein has human trials; TB-500 itself does not.
What it's being studied for
- DSoft-tissue repair
- EAthletic recovery or performance
GHK-Cu
Cosmetic ingredient
Copper tripeptide-1 · Glycyl-L-histidyl-L-lysine copper
Skin & longevity
A three-amino-acid copper peptide. Small cosmetic studies support topical use; injectable use has no human trials.
What it's being studied for
- CSkin appearance (topical)
- DSystemic anti-aging (non-topical)
CJC-1295 with DAC · DAC:GRF
Hormone research
A lab-made GHRH analogue that raises growth hormone and IGF-1 for days. Development stopped in 2006; no outcome trials.
What it's being studied for
- CRaises growth hormone and IGF-1
- EFat loss, muscle gain, anti-aging
Ipamorelin
Not FDA-approved
NNC 26-0161
Hormone research
A five-amino-acid ghrelin mimic that triggers growth hormone pulses. Its one phase 2 program did not beat placebo.
What it's being studied for
- CTriggers growth hormone release
- BPostoperative ileus recovery
- EFat loss, muscle, sleep, anti-aging
TH9507
Hormone research
The only FDA-approved GHRH analogue. Reduces belly (visceral) fat in people with HIV-associated lipodystrophy.
What it's being studied for
- AVisceral fat reduction in HIV-associated lipodystrophy
- BLiver fat and fatty liver disease in people with HIV
- EFat loss or anti-aging in people without HIV
Sermorelin
Not FDA-approved
Geref
Hormone research
The first 29 amino acids of GHRH. Once FDA-approved for children with GH deficiency; the US product was discontinued in 2008.
What it's being studied for
- BGrowth in children with GH deficiency
- CRaising GH and IGF-1 in older adults
- EAnti-aging, fat loss or muscle gain in adults
Mitochondrial open reading frame of the 12S rRNA-c
Skin & longevity
A 16-amino-acid peptide encoded in mitochondrial DNA. Mouse studies show metabolic benefits; no human treatment trials are published.
What it's being studied for
- DInsulin sensitivity and obesity
- DExercise capacity, longevity
Epithalon · Epithalone
Skin & longevity
A four-amino-acid peptide promoted for telomeres and longevity. Evidence comes almost entirely from one Russian research group.
What it's being studied for
- DTelomere lengthening
- DLonger lifespan / slower aging in humans
TP-7 · Selank acetate
Brain & mood
A seven-amino-acid peptide registered in Russia as an anxiety treatment. Not approved in the US; evidence is small and mostly Russian-language.
What it's being studied for
- CGeneralized anxiety and neurasthenia
- ECognitive enhancement in healthy people
MEHFPGP
Brain & mood
A Russian nasal peptide based on a fragment of ACTH, used there for stroke and cognition. Not approved in the US.
What it's being studied for
- CRecovery after ischemic stroke
- ECognitive enhancement in healthy people
PT-141 (Bremelanotide)
FDA-approved
Bremelanotide
Melanocortin research
FDA-approved for one prescription use in premenopausal women. Acts on brain melanocortin receptors.
What it's being studied for
- ALow sexual desire (HSDD) in premenopausal women
- CLibido or erectile function in men
Melanotan II
Not FDA-approved
MT-II · MT2
Melanocortin research
An unapproved melanocortin peptide that darkens skin and has other systemic effects. Linked to case reports of changing moles and melanoma.
What it's being studied for
- CSkin pigmentation
- CErectile function
- ESunless pigmentation safety
Anti-Obesity Drug 9604 · hGH fragment 176-191 analogue
Weight & metabolism
A growth hormone fragment developed as a fat-loss drug. Worked in obese mice; human development stopped. Not FDA-approved.
What it's being studied for
- DFat loss
- DCartilage or joint repair
Lys-Pro-Val
Immune & gut
A three-amino-acid fragment of α-MSH that reduced colitis in mice. No human trials published.
What it's being studied for
- DInflammatory bowel disease
- ESkin inflammation, 'leaky gut', general anti-inflammatory use
Thymosin Alpha-1
Not FDA-approved
Thymalfasin · Zadaxin
Immune & gut
An immune-signalling peptide approved in several countries outside the US. A 2025 phase 3 sepsis trial found no mortality benefit.
What it's being studied for
- BReducing death from sepsis
- EGeneral immune boosting in healthy people
SS-31 (Elamipretide)
FDA-approved
Elamipretide · Forzinity
Skin & longevity
A mitochondria-targeting peptide. FDA granted accelerated approval in 2025 for Barth syndrome, a rare genetic disease.
What it's being studied for
- BBarth syndrome
- BPrimary mitochondrial myopathy
- DSlowing aging / energy in healthy people
Cagrilintide
In clinical trials
CagriSema (with semaglutide) · NN9838
Weight & metabolism
An amylin-mimicking peptide that slows stomach emptying and curbs appetite. In the 3,417-person REDEFINE 1 trial, it was tested alone and paired with semaglutide.
What it's being studied for
- AWeight loss combined with semaglutide (CagriSema)
- BWeight loss on its own
- BBlood sugar in type 2 diabetes (as CagriSema)
Survodutide
In clinical trials
BI 456906
Weight & metabolism
A weekly injection that acts on GLP-1 and glucagon receptors. In SYNCHRONIZE-1 (725 adults, 76 weeks), weight fell about 13% on the higher dose vs 5% on placebo.
What it's being studied for
- AWeight loss in adults with obesity
- BLiver fat and fatty liver disease (MASH)
Mazdutide
Approved in China only
IBI362 · LY3305677
Weight & metabolism
A weekly GLP-1 and glucagon dual agonist from Innovent and Lilly. In GLORY-1 (610 adults in China), weight fell up to about 15% at 48 weeks.
What it's being studied for
- AWeight loss in adults with obesity
- ABlood sugar in type 2 diabetes
Delta sleep-inducing peptide · Emideltide
Brain & mood
A small brain peptide first isolated in 1977. Most human studies are small 1980s–90s trials that FDA called difficult to interpret.
What it's being studied for
- CSleep and insomnia
- COpioid or alcohol withdrawal symptoms
Cathelicidin LL-37
Immune & gut
A peptide the body makes to fight microbes. Applied to leg ulcers, it beat placebo in a small trial, but a larger 148-person trial found no overall benefit.
What it's being studied for
- BHealing of chronic leg ulcers (applied to skin)
- DFighting infections
Kisspeptin-10
Not FDA-approved
KP-10 · Metastin 45–54
Hormone research
A fragment of the hormone that switches on the reproductive axis. In small human studies it raises LH and testosterone within hours.
What it's being studied for
- CRaising LH and testosterone
- BEgg maturation in IVF (studied as kisspeptin-54)
Grades are editorial summaries of published research, as of October 2026. The full guide adds safety notes, half-life, regulatory status and sources for every peptide.