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№ 024

IGF-1 LR3

Long-acting form of insulin-like growth factor 1. Used for muscle anabolism. Limited human safety data and a real side-effect profile — handle with discipline.

GH-axis
Evidence: Limited
Half-life
~20-30 hours
Route
Subcutaneous
Cycle
4 weeks max, well-spaced breaks
Schedule
Daily
In plain English

IGF-1 LR3 is a long-acting form of insulin-like growth factor 1. Used for muscle anabolism, but human safety data is thin and the side-effect profile (low blood sugar, organ growth concerns) is real. Treat carefully, short cycles only.

Status & legality
Natty?
Not natty

Long-acting IGF-1 analog. Universally banned in tested sport.

FDA
Not approved

Mecasermin (Increlex) approved 2005 for severe primary IGF-1 deficiency. IGF-1 LR3 specifically (research analog) is NOT FDA approved.

Compounding
Category 2

FDA flagged as significant safety risk; restricted from compounding pharmacies.

WADA
Banned (S2)
Prescribed

Increlex prescribed by pediatric endocrinology for IGF-1 deficiency. IGF-1 LR3 is not prescribed.

Who it's for

  • →Experienced users who already have GH-axis baseline
  • →Short, focused anabolism cycles

What to expect

  1. Week 1

    Pumps and fullness in trained muscle. Mild hypoglycemia risk.

  2. Week 4

    Nutrient partitioning shifts noticeably. Plateau approaching by week 4.

  3. Week 8

    Cycle endpoint already passed. Cycle off well before this point.

Dosing protocol

30-60 mcg sub-q daily, post-workout, with carbs nearby to manage hypoglycemia.

Stacks well with

Standalone for short anabolism windows

Side effects

01Hypoglycemia (low blood sugar) — eat carbs near dose
02Localized growth at injection site
03Theoretical: visceral organ growth at chronic high doses
04Headache

When NOT to use

  • ⚠Active malignancy (real concern with IGF-1)
  • ⚠Diabetic retinopathy
  • ⚠Pregnancy / nursing
  • ⚠Hypoglycemia-prone

Bloodwork to monitor

  • • Fasting glucose every 2 weeks
  • • IGF-1 baseline + at week 4

Common mistakes

  • • Running it longer than 4 weeks
  • • Dosing fasted (hypoglycemia)
  • • Stacking with insulin or insulin-sensitizers without monitoring

Educational only. User-specific dosing is between you and a qualified provider.

Frequently asked

What is IGF-1 LR3?+
IGF-1 LR3 is a long-acting form of insulin-like growth factor 1. Used for muscle anabolism, but human safety data is thin and the side-effect profile (low blood sugar, organ growth concerns) is real. Treat carefully, short cycles only.
Is IGF-1 LR3 FDA approved?+
Mecasermin (Increlex) approved 2005 for severe primary IGF-1 deficiency. IGF-1 LR3 specifically (research analog) is NOT FDA approved.
Is IGF-1 LR3 banned by WADA?+
IGF-1 LR3 is on the WADA prohibited list under Banned (S2).
Are you still natty after taking IGF-1 LR3?+
No. Long-acting IGF-1 analog. Universally banned in tested sport.
Do doctors prescribe IGF-1 LR3?+
Increlex prescribed by pediatric endocrinology for IGF-1 deficiency. IGF-1 LR3 is not prescribed.
What's the typical dose of IGF-1 LR3?+
30-60 mcg sub-q daily, post-workout, with carbs nearby to manage hypoglycemia.
What are the side effects of IGF-1 LR3?+
Common side effects include: Hypoglycemia (low blood sugar) — eat carbs near dose; Localized growth at injection site; Theoretical: visceral organ growth at chronic high doses; Headache. Less common effects and full safety details are on the entry page.
How long until IGF-1 LR3 starts working?+
Pumps and fullness in trained muscle. Mild hypoglycemia risk.