Overview
This guide summarises commonly discussed protocols in the research peptide literature and community. Nothing here constitutes medical advice. All peptides discussed are for research and educational purposes only. Doses and cycles described reflect what appears in published studies and established research contexts — not recommendations for human use.
Researchers should always consult primary literature for the specific compound they are studying, as protocols vary significantly between peptide classes.
General Principles
Start Low, Go Slow
In research settings, the standard approach is to begin at the lower end of the dose range and titrate upward only if well tolerated. This minimises adverse effects and allows identification of the minimum effective dose.
Cycle Length and Time Off
Most research peptide protocols follow a cycle-and-recovery pattern:
- Typical cycle: 4–12 weeks, depending on the compound class
- Time off: At least equal to the cycle length (e.g., 8 weeks on, 8 weeks off)
- Rationale: Receptor downregulation, tachyphylaxis, and allowing endogenous systems to reset
Administration Routes
- Subcutaneous (SC) injection — most common for GLP-1 agonists, growth hormone secretagogues, and healing peptides. Typically administered into abdominal subcutaneous tissue.
- Intramuscular (IM) injection — less common; used for some compounds where deeper tissue delivery is desired.
- Intranasal — used for cognitive peptides such as Semax and Selank, which are designed for nasal absorption.
- Oral — limited bioavailability for most peptides; some formulations (e.g., oral semaglutide) use absorption enhancers.
Reconstitution
Most research peptides arrive as lyophilised powder and must be reconstituted with bacteriostatic water before use. See our Reconstitution and Storage Guide for full details.
GLP-1 and Multi-Incretin Agonists (Fat Loss / Metabolic)
This class includes semaglutide, tirzepatide, liraglutide, retatrutide, orforglipron, and others.
Titration Approach
GLP-1 receptor agonists follow a gradual dose-escalation protocol to mitigate gastrointestinal side effects (nausea, vomiting, diarrhoea). Published clinical trials consistently use this approach:
- Semaglutide (based on STEP trials): Starting dose 0.25 mg once weekly SC, escalating every 4 weeks through 0.5 mg, 1.0 mg, 1.7 mg, to maintenance 2.4 mg.¹
- Tirzepatide (based on SURMOUNT trials): Starting dose 2.5 mg once weekly SC, increasing by 2.5 mg every 4 weeks to a maximum of 15 mg.²
- Liraglutide (based on SCALE trials): Starting dose 0.6 mg daily SC, escalating weekly through 1.2 mg, 1.8 mg, 2.4 mg, to 3.0 mg daily.³
Cycle Length
In clinical trials, these compounds are typically studied over 68–72 weeks. In research contexts, shorter observation periods of 12–24 weeks are common.
Key Considerations
- Gastrointestinal effects are dose-dependent and most pronounced during escalation
- Titrating too quickly increases adverse event rates significantly
- Discontinuation rates in clinical trials range from 5–15%, primarily due to GI effects
Growth Hormone Secretagogues
This class includes GHRP-2, GHRP-6, ipamorelin, hexarelin, CJC-1295, and sermorelin.
Typical Research Dose Ranges
- CJC-1295 (with DAC): 1–2 mg once weekly SC; CJC-1295 (without DAC / Modified GRF 1-29): 100–300 mcg 1–3 times daily SC⁴
- Ipamorelin: 100–300 mcg 1–3 times daily SC⁵
- GHRP-2: 100–300 mcg 1–3 times daily SC⁶
- GHRP-6: 100–300 mcg 1–3 times daily SC⁶
- Hexarelin: 100 mcg 1–3 times daily SC⁷
- Sermorelin: 0.5–1.0 mg daily SC at bedtime⁸
Stacking
GHRPs (e.g., ipamorelin, GHRP-2) are commonly combined with GHRH analogues (e.g., CJC-1295 without DAC) in research settings, as they act via complementary pathways to amplify growth hormone release. The combination is often referred to as a "pulse" protocol, administered 1–3 times daily.
Timing
- Administered on an empty stomach (2–3 hours after eating), as insulin and somatostatin suppress GH release
- Bedtime administration is common to align with natural GH pulse timing
- Avoid food for 20–30 minutes post-administration
Cycle Length
- Typical: 4–12 weeks on, followed by 4 weeks off
- Longer cycles (12+ weeks) increase risk of receptor desensitisation
- GHRP-6 and hexarelin show more rapid desensitisation than ipamorelin
Healing Peptides
BPC-157
- Commonly discussed dose: 250–500 mcg 1–2 times daily SC or IM⁹
- Cycle length: 2–4 weeks, with a 2-week break before repeating if needed
- Note: BPC-157 remains an experimental compound with no human clinical trials. All evidence is preclinical (animal models).¹⁰
TB-500 (Thymosin Beta-4)
- Commonly discussed dose: 2.0–5.0 mg per week, divided into 1–2 administrations SC¹¹
- Loading phase: 4–6 weeks at the higher end
- Maintenance phase: 4–6 weeks at a reduced dose (1–2 mg/week)
- Cycle length: 8–12 weeks total, followed by 4+ weeks off
- Note: Evidence is primarily from animal and in vitro studies
Cognitive Peptides
Semax
- Route: Intranasal
- Commonly discussed dose: 300–600 mcg per day, divided into 2–3 administrations
- Cycle length: 3–14 days on, 1–3 weeks off
- Note: Semax is approved in Russia for clinical use but has limited Western clinical literature¹²
Selank
- Route: Intranasal
- Commonly discussed dose: 250–900 mcg per day, divided into 2–3 administrations
- Cycle length: 5–10 days on, followed by a break of at least equal length
Dihexa
- Route: Subcutaneous or oral (sublingual)
- Commonly discussed dose: 5–10 mg daily
- Note: Dihexa is an experimental nootropic with only preclinical evidence. No human trials have been published.¹³
Longevity and Mitochondrial Peptides
MOTS-c
- Commonly discussed dose: 5–10 mg once weekly SC
- Cycle length: 4–8 weeks on, 4 weeks off
- Note: Evidence is primarily from in vitro and animal studies¹⁴
Epitalon
- Route: Subcutaneous
- Commonly discussed dose: 5–10 mg daily for 10–20 days
- Cycle length: 10–20 days, repeated after 3–6 months
- Note: Limited human data; primarily from Russian research¹⁵
5-Amino-1MQ
- Commonly discussed dose: 25–50 mg daily
- Note: Experimental; evidence is preclinical¹⁶
Skin and Hair Peptides
GHK-Cu (Copper Tripeptide-1)
- Topical: Used in skincare formulations at concentrations of 0.05–3%
- Subcutaneous: 1.5–5 mg daily, 5 days on / 2 days off
- Cycle length: 4–12 weeks
- Note: Has substantial in vitro and some clinical evidence for wound healing and skin repair¹⁷
Blood Work Recommendations
Monitoring blood work is essential in any peptide research protocol. Key markers vary by compound class:
| Compound Class | Key Markers |
|---|---|
| GLP-1 / Metabolic | HbA1c, fasting glucose, lipid panel, liver enzymes, amylase/lipase |
| Growth Hormone Secretagogues | IGF-1, GH, fasting glucose, insulin, thyroid panel |
| Healing Peptides | Inflammatory markers (CRP), complete blood count |
| Cognitive Peptides | Baseline cognitive assessment, cortisol |
See our Blood Work Interpretation Guide for detailed guidance.
Important Cautions
- Receptor desensitisation — Prolonged use without breaks reduces efficacy. This is well-documented for GHRPs and is the rationale for cycling.
- Individual variability — Responses vary significantly based on genetics, body composition, age, and sex. What works in one research subject may not translate.
- Drug interactions — GLP-1 agonists delay gastric emptying, which can affect absorption of oral medications. GH secretagogues may interact with glucocorticoids and thyroid medications.
- Quality matters — Only use peptides from vendors that provide Certificates of Analysis (COAs) from third-party laboratories. See our Vendor Vetting Guide.
UK Legal Context
Most research peptides are legal to purchase and possess in the UK for research purposes. They are not licensed medicines and must not be sold or marketed for human consumption. Growth hormone and related secretagogues fall under additional regulatory scrutiny — see our UK Legal Status Guide for full details.
References
- Wilding JPH, et al. "Once-Weekly Semaglutide in Adults with Overweight or Obesity." New England Journal of Medicine, 2021. DOI: 10.1056/NEJMoa2032183
- Jastreboff AM, et al. "Tirzepatide Once Weekly for the Treatment of Obesity." New England Journal of Medicine, 2022. DOI: 10.1056/NEJMoa2206038
- Pi-Sunyer X, et al. "A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management." New England Journal of Medicine, 2015. DOI: 10.1056/NEJMoa1411892
- Teichman SL, et al. "Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults." Journal of Clinical Endocrinology & Metabolism, 2006. DOI: 10.1210/jc.2005-1536
- Raun K, et al. "Ipamorelin, the first selective growth hormone secretagogue." European Journal of Endocrinology, 1998. DOI: 10.1530/eje.0.1390532
- Bowers CY, et al. "Structure-activity relationships of the GHRP/GHS class of peptides." Endocrine, 2001. PMID: 11762978
- Muccioli G, et al. "Hexarelin, a growth hormone secretagogue, exerts cardioprotective effects." Journal of Endocrinology, 2001. PMID: 11773080
- Mericq V, et al. "Changes in growth hormone (GH) pulse frequency and GH responsiveness to GHRH in growth hormone-deficient (GHD) children treated with GHRH." Journal of Clinical Endocrinology & Metabolism, 1997. PMID: 9328351
- Sikiric P, et al. "Brain-gut axis and pentadecapeptide BPC 157: theoretical and practical implications." Journal of Physiology and Pharmacology, 2015. PMID: 26786845
- Sikiric P, et al. "Stable gastric pentadecapeptide BPC 157 as a tool for preventing organ damage." Current Pharmaceutical Design, 2018. DOI: 10.2174/1381612824666180620111842
- Goldstein AL, et al. "Thymosin Beta4: a new approach to treating damaged hearts." Future Cardiology, 2010. PMID: 20001806
- Inozemtseva LS, et al. "Semax and Proglylam in treatment of acute optic neuritis." Neuroscience and Behavioral Physiology, 2008. PMID: 18259563
- Wright JW, et al. "Dihexa (N-hexanoic-Tyr-Ile-(6) aminohexanoic amide) is a potent cognition-enhancing peptide." ACS Chemical Neuroscience, 2017. DOI: 10.1021/acschemneuro.6b00336
- Lee C, et al. "The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance." Cell Metabolism, 2015. DOI: 10.1016/j.cmet.2015.02.009
- Khavinson VK, et al. "Peptide regulation of aging." Bulletin of Experimental Biology and Medicine, 2002. PMID: 12459942
- George J, et al. "NNMT inhibitor 5-amino-1MQ attenuates lipopolysaccharide-induced inflammatory response." Biochemical and Biophysical Research Communications, 2020. DOI: 10.1016/j.bbrc.2020.07.041
- Pickart L, et al. "GHK-Cu: A Human Copper-Binding Peptide with Biologic and Therapeutic Actions." Antioxidants & Redox Signaling, 2021. DOI: 10.1089/ars.2020.9102