💪 Growth Factors & Muscle Building
15 peptides in this category
CJC-1295
CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH), designed with a longer half-life to support prolonged GH secretion in research settings. It is studied for its pharmacokinetic improvements over natural GHRH, especially when combined with GHRP peptides. The DAC modification allows for extended half-life and reduced injection frequency while significantly elevating IGF-1 levels.
Standard dose (no DAC / Mod GRF 1-29): 100 mcg SQ per injection, 2–3x daily. Best timing: 30 min before meals or at bedtime. Common protocol: 5 days on, 2 days off in 8–12 week cycles. Often combined with a GHRP (Ipamorelin, GHRP-2, or GHRP-6) for synergistic GH release.
CJC-1295 with DAC
CJC-1295 with DAC (Drug Affinity Complex) is a long-acting growth hormone-releasing hormone (GHRH) analog. The DAC modification extends its half-life to 6–8 days by binding to serum albumin, enabling once or twice-weekly dosing instead of the multiple daily injections required by the no-DAC version (Mod GRF 1-29). It produces sustained, non-pulsatile GH elevation.
Standard dose: 600 mcg SQ 1–2x weekly (spaced 3–4 days apart). Range: 300–1000 mcg per injection. Start low (300 mcg) and titrate up based on tolerance. Cycle: 8–12 weeks on, 4 weeks off. The extended half-life (~8 days) from the DAC modification allows weekly dosing vs. the 2–3x daily required for CJC-1295 no DAC.
Follistatin 344
Follistatin 344 (FS344) is a potent myostatin inhibitor that promotes muscle hypertrophy and strength by suppressing GDF-8 and activin pathways. It is explored in gene and peptide therapies for muscle-wasting diseases and performance enhancement. Human safety and regulatory pathways are still under evaluation.
1 mg/kg SubQ once weekly for 4–6 weeks. Some protocols use 1–2 mg SubQ every 3–4 days depending on muscle gain goals.
Frag 176-191
Frag 176-191 is a synthetic peptide fragment derived from the C-terminal region of human growth hormone (hGH). It has been studied in preclinical models for its ability to modulate fat metabolism without the insulin or IGF-1 signaling typically associated with full-length hGH. It is not considered anabolic but is of interest for its targeted lipolytic properties in laboratory research.
500 mcg SubQ 1–2x daily (preferably fasted in AM and/or pre-bed). Cycle for 4–8 weeks.
GDF-8 (Myostatin Inhibitor)
GDF-8, also known as Myostatin, is a negative regulator of muscle growth. Inhibiting GDF-8 through peptide analogs or propeptides has shown promise in increasing muscle mass and preventing muscle wasting in conditions like muscular dystrophy and cachexia. Though animal studies are promising, translation to human therapies has been limited by safety and delivery challenges.
Typical dosing ranges from 50–200 mcg SubQ 1–2x weekly for 6–12 week cycles. Clinical protocol still experimental.
GHRP-2
GHRP-2 is a potent growth hormone secretagogue that stimulates the natural release of GH via the ghrelin receptor. It has been evaluated in preclinical and limited human research for its endocrine and appetite-regulating effects. It supports GH-IGF-1 axis activation with minimal prolactin or cortisol impact at moderate doses.
Standard dose: 100–300 mcg SQ 1–2x daily. Best administered 30 min before meals or at bedtime to coincide with natural GH pulse patterns. Use in 6–12 week cycles, followed by 2–4 week break to reset receptor sensitivity. Often stacked with CJC-1295 (no DAC) or GHRP-6.
GHRP-6
GHRP-6 is a growth hormone-releasing hexapeptide that mimics ghrelin to stimulate the pituitary gland. It is studied in both preclinical and clinical settings for its GH-promoting and appetite-stimulating properties; commonly stacked with CJC-1295 for synergistic GH release.
200 mcg SubQ 1–2x daily, or 30 mcg intranasal 1–2x daily. Best used in 8–12 week cycles.
Hexarelin
Hexarelin is a potent growth hormone secretagogue peptide that stimulates GH release via ghrelin receptor binding. It is studied in animal models and human research for its robust GH stimulation and potential cardiovascular effects. Although effective, long-term continuous use may lead to GH axis desensitization.
Standard dose: 1 mcg/kg SQ daily (typically ~50–100 mcg for most adults). Literature: 100 mcg SQ 1–2x daily in limited human studies. Protocol: 5 days on, 2 days off or daily for 8–12 weeks with equal time off to prevent GH receptor desensitization.
IGF-1 DES
IGF-1 DES is a truncated, highly active form of IGF-1 with enhanced potency at muscle sites due to its low affinity for IGFBPs. It is studied for its potent anabolic signaling in muscle cells, especially during acute injury or mechanical overload in preclinical models.
50 mcg/kg SubQ daily post-workout or at localized injury sites for 4–6 weeks.
IGF-1 LR3
IGF-1 LR3 is a long-acting analog of insulin-like growth factor-1 engineered for enhanced bioavailability and prolonged action. It binds IGF-1 receptors in muscle and bone to stimulate anabolic growth, repair, and recovery. It is studied for its role in cell proliferation, muscle growth, and tissue regeneration in animal models and in vitro systems.
Typical dose: 50 mcg daily SubQ post-workout or in the morning. Cycle 4–6 weeks on, followed by 4 weeks off.
Ipamorelin
Ipamorelin is a highly selective GHRP with minimal side effects compared to earlier growth hormone secretagogues. It boosts natural GH secretion while avoiding significant stimulation of cortisol or prolactin. It has been investigated in both in vitro models and animal research for anti-aging, muscle recovery, and fat-loss protocols.
Standard dose: 200 mcg SQ at bedtime or 200–300 mcg up to 3x/day. Protocol: 5 nights on, 2 nights off, in 8–12 week cycles followed by equal off time. Often combined with CJC-1295 (no DAC) for synergistic GH release.
MGF (Mechano Growth Factor)
MGF (Mechano Growth Factor) is an IGF-1 splice variant upregulated in muscle post-injury or resistance training. It activates muscle satellite cells, facilitating localized tissue repair and hypertrophy. PEGylated forms are used to extend its half-life and improve delivery. It has been studied in vitro and in animal models for its role in muscle regeneration and tissue growth signaling.
200–400 mcg SubQ or IM, 2–3x weekly post-workout. Cycle length: 6–12 weeks with time off.
MK-677 (Ibutamoren)
MK-677 (Ibutamoren) is a long-acting, orally active ghrelin mimetic that stimulates the secretion of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) by binding to the GHS-R1a receptor. It has been studied in preclinical and clinical research for its potential to support GH/IGF-1 axis signaling, muscle mass retention, and metabolic regulation in aging and disease models.
20 mg oral daily, typically taken before bed for optimal GH and sleep effects. Cycle 8–12 weeks with optional breaks.
PEG MGF
PEG MGF is a PEGylated variant of Mechano Growth Factor, a splice form of IGF-1 expressed in muscle post-exercise. PEGylation significantly prolongs its half-life, making it more effective for sustained muscle repair and hypertrophy. It has been studied for its role in muscle recovery and hypertrophy in rodent models.
Standard dose: 200 mcg SubQ 2–3 times weekly post-exercise. Cycle duration typically 6–12 weeks.
Sermorelin
Sermorelin is a synthetic GHRH analog that stimulates the pituitary to release natural growth hormone, offering a safer and more physiologic alternative to direct GH therapy. Commonly used in adults with GH deficiency, it supports sleep, fat metabolism, recovery, and muscle tone.
Standard dose: 1–2 mcg/kg SQ daily at bedtime (typically 100–300 mcg for most adults). Clinical range: 100–500 mcg/day in research settings. Inject nightly to mimic natural GH rhythm. Cycle: 8–12 weeks on, 4 weeks off.