Research guides
Comparison guides, regulatory explainers, and evidence-first articles for readers who want the context before the claim.
121
guides
1184
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Featured this month
Supplier due diligence
An evidence-first Ascension Peptides review: is it legit, MZ Biolabs third-party COAs, real pricing, the 50% code, shipping, product range, and research-use limits.
bacteriostatic water A label-based comparison of bacteriostatic water and sterile water for injection, covering benzyl alcohol, multi-dose discard rules, neonate and IV warnings, and when each diluent fits.
best peptides for muscle growth A buyer-focused ranking of muscle growth peptides that separates human hypertrophy outcomes from GH and IGF-1 biomarkers, with current Ascension prices, COA checks, and research-use limits.
best peptide vendors An evidence-led comparison of research peptide vendors based on batch COAs, identity and purity testing, contamination checks, policies, price transparency, and buyer red flags.
peptides for weight loss A buyer-focused ranking of peptides for weight loss, separating FDA-approved medicines from investigational and research-only compounds, with evidence, access, price, and COA checks.
BPC-157 dosage A buyer-focused BPC-157 dosage guide covering the lack of an established human dose, amounts used in small studies, 10 mg vial concentration math, Ascension pricing, and safety limits.
where to buy retatrutide A buyer-focused retatrutide sourcing guide covering Ascension Peptides R-10 and R-30 listings, coupon code PEPTIDESDE, batch COAs, current prices, and research-use limits.
where to buy SS-31 A buyer-focused SS-31 sourcing guide covering the Ascension Peptides 10 mg listing, coupon code PEPTIDESDE, batch COAs, current price, and the Forzinity distinction.
where to buy BPC-157 A buyer-focused BPC-157 sourcing guide covering the current Ascension Peptides listing, coupon code PEPTIDESDE, batch COAs, price checks, vendor red flags, and research-use limits.
where to buy GHK-Cu A buyer-focused GHK-Cu sourcing guide covering the current Ascension Peptides 100 mg listing, coupon code PEPTIDESDE, batch COAs, route differences, price checks, and research-use limits.
goserelin A source-backed review of goserelin and Zoladex for endometriosis: GnRH agonist suppression, danazol-comparator evidence, bone mineral density loss, add-back limits, and claim boundaries.
lutetium Lu 177 dotatate A careful guide to Lutathera and lutetium Lu 177 dotatate for somatostatin receptor-positive GEP-NETs: NETTER-1 evidence, peptide receptor targeting, renal monitoring, marrow risks, and claim limits.
dasiglucagon A source-backed review of dasiglucagon and Zegalogue for severe hypoglycemia: label status, ready-to-use glucagon evidence, rescue-device context, contraindications, and claim limits.
avexitide A careful review of avexitide and exendin (9-39) for post-bariatric hypoglycemia: GLP-1 receptor antagonism, human evidence, phase 3 status, and claim limits.
palopegteriparatide A source-backed guide to palopegteriparatide and Yorvipath for chronic hypoparathyroidism: FDA label status, PaTHway evidence, calcium monitoring, kidney signals, and claim limits.
angiotensin II A careful review of angiotensin II and GIAPREZA for vasodilatory shock: ATHOS-3 evidence, blood-pressure response endpoints, thromboembolic warnings, and peptide-market claim limits.
bulevirtide A source-backed guide to bulevirtide and Hepcludex for chronic hepatitis D: EU label status, NTCP entry inhibition, MYR301 trial evidence, post-treatment relapse, and claim limits.
relamorelin A careful review of relamorelin and RM-131 for diabetic gastroparesis: ghrelin receptor mechanism, phase 2 human trial signals, glycemic-control concerns, terminated phase 3 records, and claim limits.
cosyntropin A source-backed guide to cosyntropin and Cortrosyn: ACTH stimulation testing, adrenal insufficiency interpretation, assay cutoffs, medication interference, and claim limits.
pasireotide A careful review of pasireotide and Signifor for Cushing disease: trial evidence, urinary free cortisol, hyperglycemia, QT and gallbladder warnings, and claim limits.
metreleptin A source-backed guide to metreleptin and Myalept: generalized lipodystrophy evidence, leptin replacement, neutralizing antibodies, lymphoma warnings, and weight-loss claim limits.
navepegritide A careful comparison of navepegritide and vosoritide for achondroplasia: Yuviwel label status, Voxzogo evidence, CNP analog biology, growth velocity, and safety limits.
icatibant A source-backed guide to icatibant for hereditary angioedema: Firazyr label status, bradykinin B2 receptor biology, FAST trial evidence, injection reactions, and claim limits.
degarelix A careful comparison of degarelix and leuprolide in prostate cancer: GnRH antagonist versus agonist biology, testosterone flare, trial evidence, cardiovascular signals, and label limits.
larazotide acetate A source-backed look at larazotide acetate for celiac disease: tight-junction biology, randomized trial signals, terminated phase 3 status, safety limits, and claim red flags.
salmon calcitonin A careful review of calcitonin salmon nasal spray for osteoporosis, fracture evidence, malignancy signal language, nasal-route safety, and peptide-market claim limits.
peptide vendor A repeatable checklist for vetting any peptide vendor: batch COAs, named testing labs, methods, red flags, and a scorecard — with a worked example on a live store.
retatrutide A source-backed guide to retatrutide side effects: gastrointestinal events, heart-rate changes, dysesthesia, UTIs, discontinuation, GLP-1 class warnings, and evidence limits.
cagrilintide A source-backed CagriSema vs tirzepatide comparison covering the REDEFINE 4 head-to-head trial, the missed non-inferiority endpoint, estimands, and claim limits.
tesamorelin A source-backed guide to how tesamorelin works as a GHRH analog, its single FDA-approved HIV-lipodystrophy use, IGF-1 effects, and why anti-aging claims are off-label.
sermorelin A source-backed look at how sermorelin works: the GHRH(1-29) structure, the Gs-cAMP-PKA receptor cascade, pulsatile GH release, feedback, and its short half-life.
ipamorelin A plain-English guide to how ipamorelin works: GHS-R1a ghrelin-receptor binding, what "selective" GH secretagogue means, the GHRH contrast, and why mechanism is not outcome.
cjc-1295 A source-backed look at the CJC-1295 and ipamorelin stack: GHRH plus GHRP synergy rationale, human biomarker data, missing clinical evidence, and FDA limits.
bpc-157 A source-first look at BPC-157 oral versus injectable claims: gastric stability, rat absorption and pharmacokinetic data, the human evidence gap, and route limits.
tb-500 A source-backed guide to TB-500 and sport: WADA prohibited status under section S2, anti-doping detection methods, sanctions, and unregulated safety risks.
ghk-cu A source-backed look at GHK-Cu collagen and anti-aging claims, separating fibroblast and gene-level lab data from small human cosmetic studies and their limits.
kpv A cautious review of KPV peptide skin and anti-inflammatory claims, alpha-MSH mechanism, keratinocyte and dermatitis models, topical-vs-systemic limits, and FDA safety gaps.
ll-37 How LL-37, a natural antimicrobial peptide, is implicated in rosacea, psoriasis, and atopic dermatitis, and why context-dependent biology undercuts immune-boost claims.
thymosin alpha-1 How thymosin alpha-1 works at the receptor level: TLR9 and TLR2 dendritic-cell signaling, T-cell and cytokine effects, IDO tolerance balance, and mechanism limits.
ss-31 A plain-English look at how SS-31 (elamipretide) binds cardiolipin to protect mitochondria, and why its cardiovascular trials show mechanism does not equal benefit.
mots-c Is MOTS-c safe? A source-first look at human safety data, the CB4211 analog trial, side effects, product-quality risks, and where MOTS-c stands with the FDA.
aod-9604 How AOD-9604 is proposed to work: the growth hormone 176-191 fragment, the lipolysis and beta-3 adrenergic hypothesis, and why mechanism did not match trials.
semax A source-first look at Semax mechanisms: its ACTH(4-10) melanocortin origin, BDNF and neurotrophin signaling, enzyme inhibition, and where the evidence stops.
selank A careful Selank vs Semax comparison: tuftsin vs ACTH origins, GABA vs BDNF mechanisms, the shared fMRI study, limited Russian evidence, and FDA status.
dsip A cautious look at DSIP beyond sleep, including old alcohol and opiate withdrawal pilots, a small pain study, preclinical stress and antioxidant data, and FDA limits.
bremelanotide A source-backed guide to bremelanotide (Vyleesi/PT-141): FDA approval, MC4R brain mechanism, RECONNECT phase 3 trial evidence, the HSDD indication, and claim limits.
melanotan ii How Melanotan II, afamelanotide (Scenesse), and bremelanotide differ in melanocortin receptor profile and regulatory status, and why approval does not transfer.
kisspeptin A plain-English guide to how kisspeptin works: KISS1R signaling, GnRH neuron control, the KNDy pulse generator, the LH surge, and why mechanism is not a protocol.
epitalon Why Epitalon's evidence traces almost entirely to one Russian research group, the epithalamin-versus-synthetic confusion, and the independent replication gap.
teduglutide A source-backed guide to teduglutide for short bowel syndrome, including GLP-2 biology, Gattex label limits, parenteral support evidence, polyps, and fluid-overload warnings.
ziconotide A cautious guide to ziconotide and Prialt, including intrathecal severe-pain evidence, N-type calcium-channel biology, boxed neuropsychiatric warnings, and peptide-market claim limits.
setmelanotide A source-backed guide to setmelanotide for rare genetic and hypothalamic obesity, including BBS, POMC, PCSK1, LEPR, label limits, and safety warnings.
desmopressin A cautious guide to desmopressin side effects, hyponatremia risk, nocturia evidence, fluid restriction, older-adult cautions, and peptide-product claim limits.
linaclotide A source-backed comparison of Linzess and Trulance, including GC-C peptide biology, IBS-C and CIC evidence, diarrhea risk, pediatric warnings, and label boundaries.
terlipressin A cautious guide to terlipressin for hepatorenal syndrome, including CONFIRM evidence, albumin context, respiratory failure warnings, ischemia risk, and claim limits.
octreotide A source-backed guide to octreotide and lanreotide, including acromegaly, neuroendocrine tumor evidence, gallbladder and glucose warnings, and peptide-market claim limits.
IGF-1 LR3 A cautious guide to IGF-1 LR3 and mecasermin claims, including severe primary IGF-1 deficiency evidence, hypoglycemia, malignancy warnings, and black-market product limits.
pramlintide A source-backed guide to pramlintide weight-loss claims, Symlin label limits, amylin biology, insulin-related hypoglycemia risk, and cagrilintide comparisons.
teriparatide A source-backed comparison of teriparatide and abaloparatide for osteoporosis, including fracture evidence, PTH analog biology, treatment-duration limits, and safety warnings.
nova labs review An honest Nova Labs review for UAE and GCC research buyers, covering public COAs, independent lab verification, AED pricing, cold-chain delivery, and buyer checks.
GLP-1 bone density A source-backed guide to GLP-1 bone-density and fracture-risk claims, including semaglutide, tirzepatide, weight-loss context, DXA data, and evidence limits.
GLP-1 binge eating A cautious guide to GLP-1 binge-eating claims, including semaglutide, reward biology, limited human evidence, eating-disorder cautions, and label boundaries.
peptide COA A buyer-intent guide to peptide COA claims, including HPLC purity, mass-spec identity, sterility and endotoxin limits, lot matching, and source-quality red flags.
bacteriostatic water A source-backed guide to bacteriostatic water and peptide storage claims, including benzyl alcohol, label limits, reconstitution math, and product-quality risks.
Wegovy teens A source-backed guide to Wegovy for teens, including STEP TEENS data, adolescent label limits, pediatric safety questions, and product-category boundaries.
Ozempic hair loss A cautious guide to Ozempic and Wegovy hair-loss claims, GLP-1 alopecia signals, rapid-weight-loss explanations, labels, and evidence limits.
semaglutide A source-backed guide to semaglutide and Alzheimer claims, including EVOKE phase 3 results, observational dementia studies, mechanisms, and label limits.
oxytocin nasal spray A cautious guide to oxytocin nasal spray claims, autism randomized trials, social-bonding marketing, FDA label limits, and product-quality questions.
Ozempic alcohol cravings A source-backed guide to Ozempic alcohol craving claims, semaglutide AUD trial evidence, tirzepatide observations, GLP-1 reward biology, and label limits.
Zepbound blood pressure A source-backed guide to tirzepatide blood-pressure claims, SURMOUNT-1 ambulatory monitoring data, weight-loss context, safety warnings, and Zepbound label limits.
Wegovy cardiovascular risk A source-backed guide to Wegovy cardiovascular-risk reduction, SELECT trial evidence, semaglutide label boundaries, safety warnings, and claim limits.
GLP-1 pancreatitis A research-backed guide to GLP-1 pancreatitis and gallbladder-risk claims, semaglutide and tirzepatide label warnings, trial evidence, and product-quality limits.
Ozempic gastroparesis A source-backed guide to Ozempic gastroparesis and ileus claims, semaglutide gastric-emptying biology, Wegovy label warnings, observational evidence, and product limits.
GLP-1 suicidal ideation A research-backed guide to GLP-1 suicidal ideation claims, FDA 2026 label-change requests, semaglutide and tirzepatide evidence, and psychiatric safety limits.
Ozempic vision loss A source-backed guide to Ozempic and vision-loss claims, separating diabetic retinopathy label warnings, NAION safety signals, semaglutide evidence, and claim limits.
sermorelin A research-backed guide to sermorelin side effects, Geref regulatory history, GHRH biology, adult anti-aging claims, and growth-hormone peptide evidence limits.
GLP-1 fertility A source-backed guide to GLP-1 fertility claims, PCOS evidence, semaglutide and tirzepatide pregnancy label limits, oral-contraceptive warnings, and claim boundaries.
GLP-1 thyroid cancer A source-backed guide to GLP-1 thyroid cancer warnings, rodent C-cell tumor findings, medullary thyroid carcinoma label limits, human evidence, and screening claims.
Ozempic CKD A source-backed guide to Ozempic for chronic kidney disease, semaglutide FLOW evidence, type 2 diabetes limits, kidney endpoints, side effects, and product boundaries.
Zepbound heart failure A research-backed guide to tirzepatide and obesity-related HFpEF, SUMMIT evidence, Zepbound label boundaries, side effects, and what heart-failure claims can and cannot say.
Wegovy MASH A research-backed guide to Wegovy for MASH, semaglutide fatty-liver evidence, biopsy endpoints, accelerated approval, side effects, and claim limits.
Zepbound sleep apnea A source-backed guide to Zepbound for obstructive sleep apnea, tirzepatide SURMOUNT-OSA evidence, PAP context, side effects, and label boundaries.
Wegovy HD A source-backed guide to Wegovy HD 7.2 mg, semaglutide STEP UP evidence, FDA label limits, side effects, dysesthesia, and how higher-dose claims should be read.
GLP-1 before surgery A research-backed guide to GLP-1 drugs before surgery or endoscopy, retained gastric contents, aspiration-risk evidence, and current perioperative guidance limits.
oral GLP-1 A source-backed guide to oral GLP-1 pills, Foundayo orforglipron, Wegovy tablets, oral semaglutide evidence, label warnings, and why oral route does not make products interchangeable.
retatrutide A research-backed guide to retatrutide Phase 3 topline results, PubMed-indexed Phase 2 evidence, side effects, FDA status, compounding limits, and research-market claims.
GLP-1 muscle loss A source-backed guide to GLP-1 muscle-loss claims, DEXA body-composition evidence, lean mass versus muscle, semaglutide and tirzepatide trial data, and claim limits.
cjc-1295 A research-backed review of CJC-1295 with DAC versus no-DAC claims, human GH and IGF-1 evidence, side effects, FDA compounding status, and stack-claim limits.
ghrp-2 A source-backed guide to GHRP-2 and GHRP-6 side effects, human endocrine evidence, appetite, cortisol, glucose, FDA compounding concerns, and stack-claim limits.
bpc-157 A research-backed review of BPC-157 side effects, FDA compounding status, human evidence limits, and why tendon, ligament, gut, and injury-recovery claims need careful reading.
tb-500 A source-backed guide to TB-500, thymosin beta-4, fragment-versus-parent-molecule claims, wound-healing evidence, side-effect uncertainty, and FDA compounding context.
ipamorelin A source-backed guide to ipamorelin side effects, human pharmacology and postoperative-ileus evidence, FDA compounding concerns, and wellness-claim limits.
injection site reactions A research-backed safety guide to peptide injection-site reactions, sterility and compounding risks, dosing-error signals, and how to read product-quality claims.
selank A careful review of Selank anxiety claims, human functional-connectivity data, GABA-related mechanisms, animal evidence, FDA compounding context, and product-quality limits.
semax A research-backed review of Semax peptide claims, including BDNF and neurotrophin mechanisms, stroke-context literature, nootropic evidence limits, and FDA compounding context.
aod-9604 A research-backed review of AOD-9604 weight-loss claims, human trial limits, preclinical lipolysis data, FDA compounding concerns, WADA status, and research-market safety gaps.
dsip A cautious review of DSIP sleep claims, old human insomnia studies, unresolved mechanism questions, FDA emideltide compounding cautions, and research-market safety gaps.
cagrilintide A research-backed guide to cagrilintide, CagriSema trial evidence, gastrointestinal side effects, investigational FDA status, and why market claims need careful reading.
epitalon A cautious review of Epitalon peptide longevity claims, telomerase and telomere studies, older epithalamin human data, cancer-biology concerns, and FDA compounding cautions.
ll-37 A research-backed guide to LL-37 peptide claims, topical chronic-wound trials, antimicrobial biology, infection-marketing limits, FDA compounding cautions, and safety unknowns.
kpv A cautious review of KPV peptide gut-inflammation claims, PepT1 biology, cell and animal evidence, oral-delivery research, adjacent human data, and FDA safety cautions.
ghk-cu A source-backed guide to GHK-Cu skin and hair claims, topical cosmetic evidence, human study limits, FDA compounding context, injectable-route risks, and how to read copper-peptide marketing.
mots-c A research-backed review of MOTS-c peptide weight-loss, insulin-sensitivity, exercise, and longevity claims, including preclinical findings, human biomarker studies, a 2026 Phase 2a trial record, and safety limits.
ss-31 A research-backed guide to SS-31 and elamipretide, Forzinity's Barth syndrome approval, mitochondrial evidence, primary mitochondrial myopathy trial limits, safety warnings, and longevity claims.
thymosin alpha-1 A source-backed review of thymosin alpha-1 immune-support claims, TESTS phase 3 sepsis findings, older trial evidence, regional status, FDA compounding warnings, and safety limits.
pt-141 A research-backed guide to PT-141 side effects, Vyleesi label warnings, HSDD trial outcomes, blood-pressure effects, nausea, pigmentation risk, and the difference between approved bremelanotide and research-market products.
kisspeptin A source-backed review of kisspeptin for fertility, testosterone, and libido claims, including human endocrine studies, IVF research, HSDD data, compounding risk warnings, and where evidence remains early.
tesamorelin A research-backed guide to tesamorelin for visceral fat, HIV-associated lipodystrophy evidence, liver-fat data, GLP-1 comparisons, safety warnings, and weight-loss claim limits.
melanotan ii A research-backed guide to Melanotan II side effects, tanning-peptide claims, small human studies, online-use data, regulator warnings, and case-report safety signals.
glp-1 A research-literacy guide to GLP-1 withdrawal and maintenance evidence from semaglutide STEP trials, tirzepatide SURMOUNT-4, and newer weight-regain analyses.
glp-1 A source-backed guide to common GLP-1 adverse effects and serious safety signals, including GI effects, thyroid warnings, gallbladder disease, pancreatitis, kidney injury, retinopathy, and compounded-product risks.
glp-1 A plain-English guide to GLP-1 compounding rules after shortage changes, including 503A, 503B, essentially-copy limits, salt forms, dosing errors, and red flags.
comparison A source-aware comparison of growth-hormone peptide topics across receptor biology, evidence strength, FDA status, compounding safety concerns, and marketing claims.
comparison A research-backed comparison of retatrutide, tirzepatide, and semaglutide across receptor targets, approval status, obesity trials, cardiometabolic evidence, and open questions.
reconstitution A measurement-first guide to peptide reconstitution math, including concentration, milligrams, micrograms, milliliters, syringe units, and common calculation mistakes.
regulatory literacy A practical framework for separating FDA-approved peptide medicines, clinical-stage investigational drugs, compounded products, and research peptides sold online.
comparison A source-backed comparison of three popular recovery peptide topics, with a focus on what is human evidence, what is preclinical, and where marketing gets ahead of the data.
comparison A source-backed comparison of semaglutide, tirzepatide, retatrutide, cagrilintide, and related incretin or amylin-based peptide medicines.
comparison A practical comparison of approved GLP-1 and incretin drugs, other approved peptide medicines, and research-market peptides with thinner evidence.
research literacy A practical guide to reading peptide research without overinterpreting study design, endpoints, controls, safety reporting, or early animal and cell data.
team note A short note from the PD Team on why Peptides Defined exists, how we plan to cover peptide topics, and what readers can expect next.
Guide updates
A quiet update list for new comparison guides, calculator updates, and evidence notes. No dosing advice or sales emails.
