🧪 Peptides Facts

50 pages · each with evidence grade, legal status table, protocol data, and real sources

cognitive

Cognitive Peptides — Nootropics Reference Comparison

Semax (BDNF onset 15–20 min, PMID 18457799), Selank (GABA-A anxiolytic, PMID 19827524), Dihexa (~10M× BDNF potency, PMID 24726369, rodent only), Humanin (mitochondrial-derived, PMID 27151978).

Peptides: Dihexa Overview — HGF/MET Pathway Agonist

Bhattarai et al. 2014 (PMID 24726369): dihexa is approximately 10 million-fold more potent than BDNF at facilitating hippocampal synaptogenesis via the HGF/MET receptor pathway in rodent models.

Peptides: Semax Overview — ACTH 4-7 Pro-Gly-Pro Analogue

Semax (ACTH 4-7 Pro-Gly-Pro) increases BDNF mRNA expression in rat hippocampus within 15–20 minutes at 50–200mcg/kg doses. Russian clinical data supports nootropic use. Grade B (Russian).

Selank vs Semax — Reference Comparison Card

Selank (GABA-A modulation, anxiolytic, 250–500mcg intranasal) and Semax (BDNF upregulation, cognitive activating, 300–600mcg intranasal) — both Russian-developed, licensed in Russia, research chemicals in the West.

🧪 Longevity Peptides

Longevity Peptides — Reference Comparison Card

SS-31 Phase 2/3 (PMID 31985937), Humanin decline ~30%/decade (PMID 27151978), Epitalon lifespan +13–24% rodent (PMID 14501183), GHK-Cu collagen synthesis human data (Grade B topical).

Peptides: Epitalon Overview — Telomerase-Activating Tetrapeptide

Khavinson 2002 (PMID 12386740): epitalon (Ala-Glu-Asp-Gly) restored telomerase activity in human somatic cells and extended rodent lifespan by 13–24% in controlled studies. Grade B (Russian clinical).

Peptides: Humanin Overview — Mitochondrial-Derived Neuroprotective Peptide

Cobb 2016 (PMID 27151978): circulating humanin levels decline ~30% per decade after age 40 in humans; lower levels correlate with cardiovascular disease risk and cognitive decline in observational data.

Peptides: SS-31 (Elamipretide) — Mitochondrial Cardiolipin-Targeting Peptide

Steele 2020 (PMID 31985937): elamipretide IV infusion in heart failure with preserved ejection fraction improved 6-minute walk distance by 21m vs placebo at 4 hours; Phase 2/3 data ongoing.

🧪 Metabolic & Body Composition

Metabolic Peptides — Reference Comparison Card

Semaglutide: 14.9% weight loss (STEP 1, PMID 33567185). Tirzepatide: 22.5% (SURMOUNT-1, PMID 35658024). Tesamorelin: 15–18% visceral fat reduction (PMID 20724674). AOD-9604: Grade D.

Peptides: AOD-9604 — GH Fragment 176-191 for Lipolysis

Heffernan et al. 2001 (PMID 11713215): AOD-9604 reduced fat mass in obese mice and beta3-AR knockout mice, confirming lipolytic pathway distinct from full GH (animal study).

Peptides: Semaglutide — GLP-1 Receptor Agonist Science

Wilding et al. 2021 (PMID 33567185): semaglutide 2.4mg/week × 68 weeks achieved 14.9% mean body weight loss vs 2.4% placebo; 86.4% achieved ≥5% weight loss.

Peptides: Tesamorelin — The Only FDA-Approved GH Peptide for Body Composition

Falutz et al. 2007 (PMID 18057338): tesamorelin 2mg/day × 26 weeks reduced visceral adipose tissue by 15.2% vs placebo in HIV-associated lipodystrophy Phase 3 trial.

Peptides: Tirzepatide — Dual GIP + GLP-1 Receptor Agonist

Jastreboff 2022 (PMID 35658024): tirzepatide 15mg/week × 72 weeks achieved 22.5% mean body weight loss; 96% achieved ≥5% and 63% achieved ≥20% weight loss threshold.

protocols

Peptide Cycling Principles — Receptor Desensitization and Protocol Design

GH secretagogue receptor (GHSR) downregulates with continuous ghrelin-mimetic stimulation. Standard cycling: 8–12 weeks on / 4–8 weeks off for GH peptides to restore pituitary sensitivity.

Peptide Dosing Protocols — Master Reference Card

Semaglutide: 0.25mg/week start → 2.4mg/week maintenance (STEP 1, PMID 33567185). BPC-157: 250–500mcg/day (rodent studies, no human RCT). Ipamorelin: 100–300mcg/dose × 3 (Grade C).

Peptide PCT and Breaks — Off-Cycle Protocol Reference

GHSR downregulation follows GH secretagogue use: standard protocol is 4–8 week break after 8–12 week cycle to restore pituitary axis sensitivity. No human study defines optimal break duration.

Peptide Stacking Principles — Combination Protocols Reference

BPC-157+TB-500 stack: complementary tissue repair mechanisms (BPC-157 angiogenesis + TB-500 actin polymerization). No human combination trial; combined Grade C. Ipamorelin+CJC-1295: Grade C.

Peptide Timing and Circadian Rhythm — Injection Timing Reference

Ghrelin peaks at night and pre-meal; GH pulse amplitude greatest during slow-wave sleep. Glucose ≥6mmol/L attenuates GH release by 40–60%. Fast ≥2 hours before GH secretagogue injection.

Subcutaneous Peptide Injection Guide — Step-by-Step Reference

Standard subcutaneous injection: 27–29 gauge, 0.5-inch needle; 45° angle; pinch skin. Bacteriostatic water reconstitution: add BW slowly down vial side, do not shake. 100IU = 1mL insulin syringe.

🧪 Peptide Fundamentals

Peptides: Bioavailability by Route

Subcutaneous injection delivers 85–95% peptide bioavailability. Oral routes yield under 1% for most peptides without specific formulation enhancers like SNAC.

Peptides: Half-Life and Stability

CJC-1295 with DAC extends GHRH half-life from 30 minutes to 6–8 days via albumin binding, enabling once-weekly dosing (Ionescu & Frohman, 2006, PMID 16968793).

Peptides: Peptides vs. Steroids — Key Differences

Anabolic steroids bind the androgen receptor directly and suppress HPTA. Peptides act via membrane receptors (GHRH-R, ghrelin-R) without androgen receptor binding or HPTA suppression.

Peptides: Purity, Testing, and Sourcing

Approximately 25% of tested research chemicals contain unlabeled substances or incorrect concentrations. Third-party HPLC and MS certification is essential for quality assurance.

Peptides: Storage and Stability Reference

Lyophilized peptide powder stored at -20°C retains stability for up to 2 years. Reconstituted peptide in bacteriostatic water degrades within 30 days at 4°C.

Peptides: What Are Peptides?

Peptides occupy a molecular weight range of 500–5000 Da — too large for passive gut diffusion, yet too small to fold into stable tertiary protein structures.

🧪 Healing & Recovery Peptides

healing-recovery

Peptides: BPC-157 — Complete Overview

BPC-157 (sequence GEPPPGKPADDAGLV) activates nitric oxide synthase, upregulates VEGF, and modulates EGF-R and PDGFR-β in animal models. 10mcg/kg dose used in most rat studies. No human RCTs completed.

healing-recovery

Peptides: BPC-157 + TB-500 Stack Protocol

BPC-157 acts locally via NO pathway and VEGF; TB-500 distributes systemically via actin sequestration. Combined, they target different aspects of tissue repair.

healing-recovery

Peptides: BPC-157 for Gut Healing

BPC-157 heals NSAID-induced and ethanol-induced gastric ulcers in rats at 10mcg/kg oral dose within 24h (PMID 21548867). Unique property: stable in stomach acid. No human IBD/GI trials completed as of 2026.

healing-recovery

Peptides: BPC-157 for Tendon and Ligament Healing

Pevec 2010 (PMID 20190680): BPC-157 showed earlier vascularization at day 3, increased cross-sectional area at day 7, significant tensile strength advantage at day 14 vs control in rat Achilles model (animal study).

healing-recovery

Peptides: BPC-157 Protocol — Reference Card

BPC-157 rat studies use 10mcg/kg (≈162mcg for 70kg human by body weight). Community protocols typically use 200–400mcg per injection, 1–2x daily, 4–6 week cycles. No human dose-finding data exists.

healing-recovery

Peptides: Selank Overview

Selank modulates GABA-A receptor sensitivity and BDNF expression in rodent models, producing anxiolytic effects without sedation at 25–50mcg/kg doses. (animal study)

healing-recovery

Peptides: TB-500 — Thymosin Beta-4 Fragment Overview

TB-500 = Tβ4 fragment LKKTETQ (amino acids 17-23). Full Tβ4 studied in cardiac trials (human data). TB-500 specifically has Grade C animal evidence. Systemic distribution vs BPC-157's more local action.

healing-recovery

Peptides: TB-500 Protocol Reference Card

Thymosin beta-4 promotes angiogenesis and wound healing via actin sequestration and VEGF upregulation, supporting systemic tissue repair across multiple injury sites.

🧪 Legal Status & Safety

Peptides: BPC-157 FDA Status — Myth vs. Fact

FDA's 2023 final rule removed BPC-157 from 503B bulk drug substances list — compounding pharmacies cannot use it. BPC-157 is not a DEA-scheduled substance. WADA prohibits it under S2 peptide hormones for athletes.

Peptides: Legal Status by Jurisdiction — Full Reference

BPC-157 is FDA Category 2 (cannot be compounded) in the USA. Most GH peptides are Schedule 4 in Australia and unscheduled in the USA, UK, and EU.

Peptides: Legal Status Overview

BPC-157 was placed on the FDA Category 2 bulk drug substance list in 2023, prohibiting its use in compounded preparations. Most GH peptides remain unscheduled research chemicals.

Peptides: Safety Principles and Risk Overview

USADA testing found ~25% of research chemicals contained unlabeled controlled substances or incorrect concentrations. Most performance peptide safety data comes from animal studies, not decade-long human trials.

Peptides: Side Effects Overview by Class

GHRP-6 significantly elevates hunger via ghrelin receptor agonism. Ipamorelin shows cleaner GH release with minimal cortisol/prolactin elevation compared to GHRP-2. GLP-1 agonists cause GI effects in ~40% of users at initiation.

🧪 Collagen & Structural Peptides

collagen-structural

Peptides: Can Collagen Replace Whey for Muscle Building?

Oikawa et al. 2020 (PMID 31919531): whey but not collagen peptides stimulated myofibrillar protein synthesis acutely and over 3 days. Collagen has 0.5g leucine per 10g serving.

collagen-structural

Peptides: Collagen Peptides — Mechanisms and Evidence

Oral collagen peptides accumulate in cartilage and skin within 12–24 hours of ingestion. Proline-rich fragments stimulate chondrocyte collagen synthesis and reduce MMP activity.

collagen-structural

Peptides: GHK-Cu — Copper Tripeptide Science

GHK-Cu plasma levels decline from ~200ng/mL at age 20 to ~80ng/mL at age 60. Topical GHK-Cu showed significant fine line reduction vs placebo in human trials (Pickart 2012, PMID 23194977).

collagen-structural

Peptides: Matrikines — ECM-Derived Bioactive Fragments

Matrikines including GHK (from collagen α2(I)) and Pal-KTTKS (Matrixyl, from procollagen) upregulate collagen I, III, and fibronectin. Grade B human topical data for Pal-KTTKS (Robinson 2005, PMID 18492182).

🧪 Growth Hormone Peptides

Peptides: CJC-1295 Overview (DAC vs No-DAC)

CJC-1295 with DAC produced sustained IGF-1 elevation over 14 days in healthy adults (PMID 16368745). The no-DAC form preserves pulsatile GH secretion, preferred for most protocols.

Peptides: Ghrelin and GHRP Class Overview

Ghrelin was identified in 1999 as the endogenous GHSR ligand (PMID 10604470). Synthetic GHRPs selectively amplify GH pulses; combined with GHRH analogues, they produce 3–4× greater GH release.

Peptides: GHRP-2 Overview

GHRP-2 stimulates pulsatile GH release at 100mcg; cortisol and prolactin elevation are dose-dependent above 300mcg. Evidence grade B from human pharmacodynamic trials.

Peptides: GHRP-6 Overview

GHRP-6 was the first synthetic GHRP characterized in humans. It produces robust GH pulses at 100mcg but causes significant appetite stimulation via NPY/AgRP pathway activation.

Peptides: Growth Hormone Physiology Basics

GH pulse amplitude declines ~14% per decade after age 30. Somatostatin and GHRH compete continuously; fasting and deep NREM sleep maximize pulse amplitude.

Peptides: Ipamorelin + CJC-1295 Stack Reference Card

CJC-1295 combined with GHRP amplified IGF-1 response in humans beyond either alone (PMID 16368745). Synergy derives from simultaneous GHRH-R and GHSR stimulation.

Peptides: Ipamorelin Overview

Ipamorelin is the first selective growth hormone secretagogue with negligible cortisol and prolactin elevation at 100–300mcg doses. Evidence grade B from human pharmacokinetic studies.

Peptides: MK-677 (Ibutamoren) — Not a Peptide, Not a SARM

Nass et al. 2008 (PMID 18981487): 25mg/day MK-677 for 24 months in older adults increased IGF-1 by 40% vs placebo but also elevated fasting glucose.

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50 fact pages covering peptide fundamentals, legal status, collagen peptides, healing peptides (BPC-157, TB-500), growth hormone peptides (ipamorelin, CJC-1295), metabolic, cognitive, longevity, and dosing protocols. ← Dashboard