Comparison
Two modified IGF-1 analogs sold for muscle growth with no human evidence between them.
LR3 is the long-acting version used daily; DES is the shorter, more potent version used around workouts. Neither has human trials, and both carry real hypoglycemia risk by mechanism.
IGF-1 LR3 has an extended half-life from its modifications, so community schedules use about 20 to 50 mcg once daily. IGF-1 DES lacks the first three amino acids, binds less to binding proteins, acts shorter and more locally, and is used around 50 to 100 mcg split into trained muscles around workouts.
No. The approved IGF-1 drug (mecasermin) is plain IGF-1 for severe primary deficiency; the LR3 and DES modifications popular in bodybuilding have no human clinical literature at all. Hypoglycemia is the dominant acute risk because these are potent insulin-like molecules.
Both are unapproved for any marketed use and prohibited in sport under the WADA growth-factor category. Vials sold under these names are unverified research-market material.
| Dimension | IGF-1 LR3 | IGF-1 DES |
|---|---|---|
| Overall evidence grade | E | E |
| Evidence label | Evidence unclear | Evidence unclear |
| Regulatory status | Not FDA-approved for listed uses | Not FDA-approved for listed uses |
| Editorial confidence | Low confidence | Low confidence |
| Efficacy | 0/5 not mapped | 0/5 not mapped |
| Safety | 0/5 not mapped | 0/5 not mapped |
| Regulatory risk | 3/5 moderate | 3/5 moderate |
| Product quality risk | 3/5 moderate | 3/5 moderate |
| Primary claim categories | Muscle growth and performance | Muscle growth and performance |
WADA. The 2026 Prohibited List 2026.
Accessed 2026-06-08.
WADA states that S0 non-approved substances are prohibited at all times when they have no current approval by a governmental regulatory health authority for human therapeutic use.