IGF-1 DES vs MK-677 (Ibutamoren)
A neutral, side-by-side comparison of two performance & growth hormone peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
IGF-1 DES
IGF-1 DES (Des(1-3)IGF-1) is the naturally occurring truncated form of IGF-1, lacking the first three N-terminal amino acids (Gly-Pro-Glu). This small structural difference produces a dramatically more potent molecule: by removing the primary IGF binding protein (IGFBP-3) attachment site, IGF-1 DES circulates in free form with approximately 10x higher potency than standard IGF-1 LR3 at equivalent doses. It acts locally in tissue rather than systemically, making it the preferred form for targeted muscle hypertrophy research.
Full profileMK-677 (Ibutamoren)
Oral non-peptide growth hormone secretagogue that mimics ghrelin to stimulate GH and IGF-1 release without injection. Long half-life (~24 hours) enables once-daily oral dosing. Widely researched for body composition, sleep quality, and IGF-1 elevation.
Full profile| IGF-1 DES | MK-677 (Ibutamoren) | |
|---|---|---|
| Category | Performance & Growth Hormone | Performance & Growth Hormone |
| Also known as | Des(1-3)IGF-1, Truncated IGF-1, DES-IGF-1 | Ibutamoren, Nutrobal, MK677, L-163,191 |
| Evidence | Research-stage | Research-stage |
| Dosing range | 50mcg–150mcg mcg, 1–2x daily, preferably post-workout | 10mg–50mg mg, once daily oral |
| Administration | Subcutaneous injection, Intramuscular injection (into target muscle for local hypertrophic effect) | Oral (capsule/liquid) |
| Key side effects | Hypoglycemia (potent insulin-like effect — have fast carbohydrates nearby), Localized muscle swelling at injection site, Jaw pain / facial bone growth at very high doses (acromegaly-like — dose-dependent), Organ enlargement at excessive doses | Water retention, Increased appetite, Elevated fasting glucose (long-term), Fatigue (initial, transient) |
| Cited sources | 2 references | 2 references |
Key differences
- Administration: IGF-1 DES — Subcutaneous injection, Intramuscular injection (into target muscle for local hypertrophic effect); MK-677 (Ibutamoren) — Oral (capsule/liquid).
- Dosing units differ: IGF-1 DES is dosed in mcg, MK-677 (Ibutamoren) in mg — they operate at different scales.
- Frequency: IGF-1 DES is typically 1–2x daily, preferably post-workout; MK-677 (Ibutamoren) is once daily oral.
How each works
IGF-1 DES
The three N-terminal amino acids of IGF-1 are the primary binding site for IGFBP-3 (IGF binding protein 3), which sequesters 75–90% of circulating IGF-1 in an inactive bound form. IGF-1 DES lacks this binding site, meaning virtually all injected peptide reaches tissue receptors as free (active) IGF-1. In skeletal muscle research, Des-IGF-1 promotes satellite cell activation, myoblast proliferation, and differentiation at lower doses than LR3. It has a shorter half-life (~20–30 minutes) than LR3 but acts more intensely — particularly at the site of injection.
MK-677 (Ibutamoren)
MK-677 binds the ghrelin receptor (GHS-R1a) to stimulate pulsatile GH release and increase circulating IGF-1. Unlike peptide GHRPs it survives oral administration. Clinical trials demonstrate significant increases in GH pulsatility and IGF-1 without suppression of the endogenous GH axis, though long-term use raises glucose metabolism concerns.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.