PinnyPeptide

ACE-031 vs IGF-1 LR3

Side-by-side comparison: effects, dosing ranges, side effects, regulatory status, and reconstitution.

Peptide A

ACE-031

Muscle Growth

Soluble myostatin / activin trap — recombinant decoy of the activin IIB receptor.

Peptide B

IGF-1 LR3

Muscle Growth

Long-acting IGF-1 analog with reduced binding-protein affinity for sustained signaling.

Typical vial

1 mg

Typical dose

Per kg dosing mcg

Half-life

~10-15 days (Fc-fusion)

FDA status

Not FDA approved. Clinical development halted in 2011 after …

Typical vial

1 mg

Typical dose

20-50 mcg

Half-life

~20-30 hours

FDA status

Not FDA approved. Native recombinant rhIGF-1 (mecasermin/Inc…

ACE-031 effects

  • Inhibits myostatin and related TGF-β superfamily ligands
  • Rapid increases in lean muscle mass in clinical trials
  • Increased thigh muscle volume by MRI
  • Increased serum markers of muscle growth
  • Reduced fat mass in some trial subjects

IGF-1 LR3 effects

  • Sustained IGF-1 receptor activation (20-30 hour half-life)
  • Muscle cell hyperplasia (increased cell number, not just size)
  • Anabolic signaling via PI3K-Akt-mTOR pathway
  • Improved nutrient partitioning toward muscle
  • Enhanced recovery from training-induced damage

ACE-031 side effects

  • Capillary leak (gum bleeds, nosebleeds, telangiectasias) — clinical trial finding
  • Injection-site reactions
  • Headache
  • Potential off-target effects on vasculature and bone
  • Limited long-term safety data

IGF-1 LR3 side effects

  • Hypoglycemia (real risk — IGF-1 has insulin-like activity)
  • Joint pain and stiffness
  • Carpal tunnel-like symptoms
  • Lethargy / lightheadedness from glucose drops
  • Possible tumor-promoting effects (theoretical, dose-dependent)
  • Localized lipohypertrophy or muscle asymmetry with site injection

ACE-031 dosing ranges

Research / muscle volume increase

0.5-3 mg/kg · IV or SubQ every 2-4 weeks · Per protocol

IGF-1 LR3 dosing ranges

Research / muscle hypertrophy

20-50 mcg · Once daily (SubQ or IM), pre- or post-workout · 30-50 days per cycle

Site-specific injection (research)

20-40 mcg per site · Into trained muscle, post-workout · 30-50 days per cycle

Full ACE-031 guide → Full IGF-1 LR3 guide →

ACE-031 vs IGF-1 LR3 — common questions

What is the difference between ACE-031 and IGF-1 LR3?

ACE-031: Soluble myostatin / activin trap — recombinant decoy of the activin IIB receptor. Typical dose Per kg dosing mcg. IGF-1 LR3: Long-acting IGF-1 analog with reduced binding-protein affinity for sustained signaling. Typical dose 20-50 mcg. Both fall under the Muscle Growth category.

Can you stack ACE-031 and IGF-1 LR3?

Stacking ACE-031 with IGF-1 LR3 is a protocol-design question best raised with a clinician — it depends on your goal, current bloodwork, and whether both peptides target overlapping mechanisms. Both peptides should be tracked independently with separate injection sites and timing. PinnyPeptide supports multi-peptide stacks with automatic injection site rotation.

Which is dosed more frequently, ACE-031 or IGF-1 LR3?

ACE-031 is typically dosed: IV or SubQ every 2-4 weeks for Research / muscle volume increase. IGF-1 LR3 is typically dosed: Once daily (SubQ or IM), pre- or post-workout for Research / muscle hypertrophy; Into trained muscle, post-workout for Site-specific injection (research).

Are ACE-031 and IGF-1 LR3 FDA approved?

ACE-031: Not FDA approved. Clinical development halted in 2011 after capillary leak observations. IGF-1 LR3: Not FDA approved. Native recombinant rhIGF-1 (mecasermin/Increlex) is FDA approved for severe primary IGF-1 deficiency in children, but IGF-1 LR3 itself is not.

Related peptide comparisons

ace-031 vs b7-33ace-031 vs follistatinace-031 vs gdf-8-95ace-031 vs igf-1-desb7-33 vs igf-1-lr3cjc-1295 vs igf-1-lr3

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