Example research briefs
JavaScript is required to use the interactive Evidence Explorer. Below are summaries of common protocols covered by this tool.
GLP-1 for Fat Loss — Semaglutide or Tirzepatide
FDA-approved chronic weight management. STEP 1 trial (PMID 33567185, n=1,961): 14.9% mean weight loss at 68 weeks with semaglutide 2.4 mg. SURMOUNT-1 (PMID 35658024, n=2,539): 20.9% at 72 weeks with tirzepatide 15 mg. Evidence tier: Strong Human RCT. Titration: 0.25 mg/wk semaglutide, escalating over 16-20 weeks to 2.4 mg. Chronic treatment — weight rebounds on discontinuation in most patients. Monitoring: fasting glucose, HbA1c, lipid panel, thyroid screening, body composition. Contraindicated with personal/family history of MTC or MEN2.
CJC-1295 + Ipamorelin — GH-Axis Stack for Muscle and Recovery
Pulsatile GH elevation for body composition, sleep, and recovery. CJC-1295 (GHRH analog) + ipamorelin (ghrelin receptor agonist) hit separate receptors for additive effect. Evidence tier: Limited Human Trials. Typical cycle: 200-300 µg each, subcutaneous, bedtime, 12-16 weeks on / 4+ weeks off. Monitoring: IGF-1 at baseline and week 6-8, fasting glucose. Both compounds WADA-banned. Not FDA-approved; research-chemical sourcing.
BPC-157 + TB-500 — Tendon and Soft-Tissue Recovery
BPC-157 (Body Protection Compound 157): synthetic pentadecapeptide studied for tendon healing in animal models. Evidence tier: Animal Studies Only for musculoskeletal indications. TB-500 (thymosin beta-4 fragment): promotes cell migration and angiogenesis. Evidence tier: Limited Human Trials. Commonly used together in clinical practice for injury recovery, though the combination has not been studied in a controlled human trial. Physical therapy and eccentric loading remain the primary evidence-based intervention.
PT-141 / Bremelanotide (Vyleesi) — Sexual Function
FDA-approved melanocortin receptor agonist for hypoactive sexual desire disorder (HSDD) in premenopausal women. Evidence tier: Strong Human RCT. As-needed dosing (1.75 mg subcutaneous, 45 min before anticipated activity). Not for daily use. Transient blood pressure elevation after each dose — contraindicated in uncontrolled hypertension. Max 1 dose per 24 hours, max 8 doses per month per label.
GHK-Cu — Skin and Anti-Aging (Topical)
Copper tripeptide used topically for skin remodeling, collagen stimulation, and wound healing. Evidence tier: Limited Human Trials for topical applications. Tretinoin (prescription retinoid) has a stronger evidence base for photoaging — GHK-Cu is a peptide adjunct, not a replacement. Typically applied as a serum (1-2% concentration) alongside sunscreen and a retinoid foundation. Available over the counter as a cosmetic ingredient.
MK-677 / Ibutamoren — Oral GH Secretagogue
Oral non-peptide ghrelin mimetic. Evidence tier: Limited Human Trials. Key trial: Nass et al. 2008 (PMID 18981485, n=65) — increased lean mass and improved sleep quality. Known to impair insulin sensitivity and increase fasting glucose. A trial in elderly CHF patients was terminated early due to safety signals. 25 mg/day at bedtime, 12-16 week cycles. Monitoring: fasting glucose, HbA1c, IGF-1. WADA-banned. Not FDA-approved.
Thymalfasin / Thymosin Alpha-1 — Immune Support
28-amino-acid immune modulator approved outside the US as Zadaxin for hepatitis B adjunct therapy. Evidence tier: Strong Human RCT for labeled hepatitis indications. Promotes dendritic cell maturation and T-cell differentiation. 1.6 mg subcutaneous twice weekly for 24 weeks in approved protocol. Off-label use for general immune support is not well-studied.
Sermorelin — GHRH Analog for GH-Axis
Synthetic GHRH(1-29) analog. Evidence tier: Limited Human Trials. Was FDA-approved as Geref for GH-deficiency diagnosis before voluntary manufacturer discontinuation (~2008). Shorter half-life (~11 min) than CJC-1295; requires precise bedtime dosing aligned with nocturnal GH pulsatility. Typical cycle: 200-300 µg subcutaneous at bedtime, 12-16 weeks on / 4+ weeks off. Available through compounding pharmacies. WADA-banned.
AOD-9604 — GH-Fragment Fat Loss (Non-GLP-1 Path)
Human growth hormone fragment (amino acids 177-191). Evidence tier: Limited Human Trials. The Phase IIb clinical trial did not meet its primary endpoint. Effect size substantially smaller than GLP-1 agonists. Positioned as a non-GLP-1 alternative for patients who cannot tolerate or access semaglutide/tirzepatide. 250-300 µg subcutaneous daily, morning fasted. Caloric deficit and resistance training are the primary fat-loss drivers.
Sleep — Behavioral Foundations Before Peptide Consideration
No peptide is FDA-approved for sleep as a primary indication. CBT-I (Cognitive Behavioral Therapy for Insomnia) is the only intervention with long-term RCT efficacy matching pharmacotherapy. GH-axis peptides (CJC/Ipa, MK-677) may improve sleep architecture as a secondary effect of bedtime dosing. DSIP (Delta Sleep-Inducing Peptide) showed increased delta-wave sleep in early EEG studies but subsequent clinical results were inconsistent. Foundation work first: sleep hygiene, consistent schedule, morning light exposure, medical workup for sleep apnea.
Hair — GHK-Cu Topical + Oral Collagen
Peptide evidence for hair regrowth is limited. Topical GHK-Cu (0.05-0.2%) has small trials showing follicle-density improvements over 12-24 weeks (PMID 18644225, 29986520). Oral hydrolyzed collagen has meta-analytic support for skin but minimal hair-specific evidence. For androgenetic alopecia, standard-of-care remains topical minoxidil and finasteride — both with substantially stronger RCT evidence than any peptide. Rule out reversible causes (iron deficiency, thyroid) before any peptide adjunct. 6+ months minimum assessment window.
Gut — Oral BPC-157 (Thin Human Evidence)
BPC-157 oral use for gut concerns is popular in forum communities but has zero peer-reviewed human RCTs. Preclinical data exists for gastric ulcer and IBD models in rodents. Doses (250-500 µg/day oral) are empirically extrapolated from animal studies. A proper gut workup — H. pylori, celiac serology, fecal calprotectin, endoscopy — should be completed before any peptide consideration. Time-limited 4-8 week trial only if workup unrevealing; do not extend indefinitely.
Longevity — Evidence-Based Path (Not Peptide-Driven)
No peptide has RCT-grade evidence for general-population healthspan extension. The strongest longevity interventions are resistance training, VO2max training, adequate protein, sleep, and aggressive treatment of modifiable risk factors (hypertension, dyslipidemia, diabetes). GLP-1s show mortality benefit in CV-disease-plus-obesity populations (SELECT trial, PMID 37952131) but that is disease-indication, not general longevity. Emerging compounds (MOTS-c, SS-31/elamipretide, epithalon) have preclinical or limited human data only.
Cognitive — Semax, Selank, and Foundation Work
Semax and Selank are Russian-origin heptapeptides with limited independent Western replication. Evidence tier: Limited Human Trials. For cognitive complaints, highest-yield interventions are sleep quality, cardiovascular exercise, and treatment of underlying anxiety/depression. Dihexa (HGF agonist) has extraordinary potency in rodent cognitive models (PMID 24515786) but zero human trials and theoretical oncogenic risk via HGF/c-Met pathway. Not recommended without physician oversight and explicit informed consent.
Best Peptide for Fat Loss — Evidence Ranked
Semaglutide (Wegovy) and tirzepatide (Zepbound) have the strongest fat-loss evidence: 14.9% and 20.9% mean weight loss in large Phase III trials (PMID 33567185, PMID 35658024). Both are FDA-approved. Evidence tier: Strong Human RCT. AOD-9604 (hGH fragment 177-191) is a non-GLP-1 alternative but its Phase IIb trial did not meet the primary endpoint. MK-677 primarily affects lean mass and can worsen insulin sensitivity. Caloric deficit and resistance training drive most fat-loss outcomes regardless of peptide choice.
Best Peptide for Muscle Growth — Evidence Ranked
CJC-1295 + ipamorelin is the most commonly planned GH-axis stack for body composition. Both are evidence tier: Limited Human Trials. They stimulate GH via separate receptor pathways (GHRH and ghrelin) for additive effect. MK-677 is an oral alternative but impairs insulin sensitivity (PMID 18981485). For lean-mass preservation during fat loss, GLP-1 agonists combined with a GH secretagogue and resistance training is the protocol physicians most commonly plan. No peptide replaces resistance training and adequate protein intake.
Is BPC-157 Safe to Inject?
BPC-157 has zero published human RCTs for injectable musculoskeletal use as of April 2026. Published evidence comes from rodent tendon-healing models (PMID 18644225). Subcutaneous doses (250-500 µg/day) are extrapolated from animal studies without validated allometric scaling. It is a research chemical — not FDA-approved, not pharmaceutical-grade. Certificate of analysis and third-party testing are the minimum due diligence before sourcing. ProtocolBrief classifies injectable BPC-157 as evidence tier: Animal Studies Only.
How to Calculate Peptide Doses After Reconstitution
Divide peptide amount by water volume to get concentration. Example: 5 mg ipamorelin + 2.5 mL bacteriostatic water = 2,000 µg/mL. For a 300 µg dose: 300 ÷ 2,000 = 0.15 mL = 15 units on a U-100 insulin syringe. Common vial sizes: 2 mg, 5 mg, 10 mg. Common water volumes: 1 mL, 2 mL, 2.5 mL. Always verify the concentration before drawing. ProtocolBrief calculates reconstitution math automatically for every injectable compound in the research brief.
Semaglutide vs Tirzepatide — Head-to-Head Comparison
Semaglutide (Wegovy) is a GLP-1 receptor agonist: 14.9% mean weight loss at 68 weeks (STEP 1, PMID 33567185, n=1,961). Tirzepatide (Zepbound) is a dual GIP/GLP-1 agonist: 20.9% at 72 weeks (SURMOUNT-1, PMID 35658024, n=2,539). Both are FDA-approved for chronic weight management. Tirzepatide showed greater efficacy in head-to-head data (SURPASS-2, PMID 34170647). Both carry class-level risks including pancreatitis and gallbladder events. Both require 16-20 week titration. Weight rebounds on discontinuation for both (PMID 36216945). Compare at protocolbrief.com/#compare/semaglutide-vs-tirzepatide.
BPC-157 vs TB-500 — Head-to-Head Comparison
BPC-157 is a synthetic gastric pentadecapeptide studied in rodent tendon-healing models (PMID 18644225). Evidence tier: Animal Studies Only for musculoskeletal indications. Zero published human RCTs. TB-500 (thymosin beta-4 fragment) promotes cell migration and angiogenesis. Evidence tier: Limited Human Trials. Both are research chemicals with no FDA approval. Commonly combined in clinical practice for injury recovery, though the combination has not been studied in a controlled human trial. Physical therapy remains the primary evidence-based intervention. Compare at protocolbrief.com/#compare/BPC-157-vs-TB-500.
CJC-1295 vs Sermorelin — Head-to-Head Comparison
Both are GHRH analogs stimulating pulsatile GH release. CJC-1295 (Mod GRF 1-29, non-DAC) has a longer half-life (~30 min) and is typically paired with ipamorelin. Sermorelin (GHRH 1-29) was formerly FDA-approved as Geref before voluntary manufacturer discontinuation (~2008). Shorter half-life (~11 min) requires precise bedtime dosing. Both are evidence tier: Limited Human Trials. Both are WADA-banned research chemicals. Both dosed 200-300 µg subcutaneous at bedtime, 12-16 weeks on / 4+ weeks off. Compare at protocolbrief.com/#compare/CJC-1295-vs-sermorelin.
MK-677 vs Ipamorelin — Head-to-Head Comparison
MK-677 (ibutamoren) is an oral non-peptide ghrelin mimetic. 25 mg/day, no injection required. Known to impair insulin sensitivity (PMID 18981485). Ipamorelin is a selective injectable ghrelin-receptor agonist, 200-300 µg subcutaneous at bedtime. Does not elevate cortisol or prolactin (PMID 9849822). Both are evidence tier: Limited Human Trials. MK-677 is simpler (oral) but has worse metabolic side effects. Ipamorelin requires reconstitution and injection but has a cleaner safety profile. Both are WADA-banned research chemicals. Compare at protocolbrief.com/#compare/MK-677-vs-ipamorelin.
Compare Peptides Head-to-Head
ProtocolBrief includes a comparison engine for 20 active compounds. Compare any two peptides side-by-side: mechanism, evidence tier, published pros and cons, regulatory status, and PubMed citations. Comparisons are deep-linkable for sharing and bookmarking.