Last updated: May 18, 2026
GH-stimulating peptides
CJC-1295 + Ipamorelin stack
The most-studied combination. Stimulates pulsatile GH release, elevating IGF-1 by ~50-100% with consistent dosing. Body composition effects are gradual.
Sermorelin
GHRH (1-29) analog. Similar GH-elevation effect but shorter half-life and more frequent dosing needed.
Tesamorelin
FDA-approved GHRH analog (for HIV lipodystrophy). Studied off-label for body composition effects in other populations.
IGF-1 family peptides
IGF-1 LR3
Long-acting analog of IGF-1 with R3 substitution and 13-amino-acid extension. Half-life ~30 hours. Most direct anabolic effects of any peptide. Sub-Q research dosing 50-100 mcg post-workout.
IGF-1 DES (1-3)
Truncated 67-amino-acid form. Localized action, very short half-life. Used for localized muscle development.
MGF (Mechano Growth Factor) / PEG-MGF
IGF-1Ec splice variant produced in response to mechanical loading. PEGylated version (PEG-MGF) has extended half-life for systemic dosing.
Myostatin inhibitors
Follistatin 344
Binds and neutralizes myostatin and activin A — both negative regulators of muscle growth. Animal models show dramatic muscle growth; human evidence limited.
YK-11
Not a peptide but often discussed alongside — a SARM/myostatin modulator. Mentioned for context only.
Recovery peptides (indirect effect)
BPC-157
Not directly anabolic but accelerates recovery, which permits higher training volume.
TB-500
Tissue repair peptide. Pairs with BPC-157 for recovery protocols.
Realistic effects
Peptides studied for muscle growth produce gradual effects over 8-12+ weeks. Most published research shows modest changes in body composition rather than the rapid effects associated with anabolic-androgenic steroids. Strength gains are typically smaller than equivalent anabolic interventions.
Which peptide is “best” for muscle growth?<br />
IGF-1 LR3 has the most direct anabolic effect. GH-stimulating stacks (CJC-1295/Ipamorelin) work indirectly via elevated GH/IGF-1. Follistatin is theoretically powerful but has limited human evidence.
Can peptides replace steroids?<br />
No. Effect sizes are substantially smaller than anabolic-androgenic steroids in controlled trials. Peptides also have different mechanisms and risk profiles.
How long until results?<br />
4-8 weeks for measurable changes in body composition with consistent dosing. 12+ weeks for substantial visible changes.
Are these peptides WADA-banned?<br />
Yes — virtually all GH-stimulating peptides, IGF-1 analogs, and myostatin inhibitors are WADA-banned for competitive athletes.