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Growth Hormone Axis
The first 29 amino acids of natural GHRH. FDA-approved as Geref until it was withdrawn in 2008.
Growth Hormone Axis
A long-acting lab version of IGF-1, the hormone growth hormone works through.
Sermorelin is not FDA-approved and rated 4/5 for evidence; IGF-1 LR3 is not FDA-approved and rated 1/5. Sermorelin has more human evidence behind it. Both are banned in sport by WADA. Both are used for growth hormone axis goals.
| Compare | Sermorelin The first 29 amino acids of natural GHRH. FDA-approved as Geref until it was withdrawn in 2008. | IGF-1 LR3 A long-acting lab version of IGF-1, the hormone growth hormone works through. |
|---|---|---|
| Category | Growth Hormone Axis | Growth Hormone Axis |
| Evidence | 4/5Human trials supported its former approval for pediatric GH deficiency. Evidence for adult anti-aging use is small and older. | 1/5Developed as a cell-culture reagent. No human clinical trials of LR3. Human data exists only for the approved native IGF-1 drug (mecasermin), a different product. |
| FDA status | Formerly FDA-approved (Geref) — discontinued 2008 | Not FDA-approved |
| WADA (sport) | Banned | Banned |
| Also known as | Geref, GRF 1-29 NH2, Sermorelin acetate | Long R3 IGF-1, Long Arg3 IGF-1, LR3-IGF-1 |
| How it works | Binds the GHRH receptor on the pituitary, triggering a short pulse of growth hormone and a rise in IGF-1. The body's normal feedback (somatostatin) still applies, so levels stay within a more natural range than injected GH. | Activates the IGF-1 receptor, which drives cell growth, protein building and glucose uptake. Because it largely escapes IGF-binding proteins, more of it stays free and active than with native IGF-1. |
| Half-life | About 10–20 minutes; the GH pulse lasts a few hours | Longer than native IGF-1 (often quoted as about 20–30 hours); not well studied in humans |
| Commonly reported doses |
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| Route | Subcutaneous | Subcutaneous or intramuscular |
| Good once mixed | ~21 days in the fridge | ~21 days in the fridge |
| Top side effects |
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| Lowest research-listing price per mg | $3.60 (10 mg vial, 40% off) | $41.99 (1 mg vial, 40% off) |
| Latest lab purity | 99.41% (lot SER0002) | 99.03% (lot IGF0002) |
Want a third? Add another peptide. Doses are commonly reported ranges, not recommendations.
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Sermorelin is not FDA-approved and rated 4/5 for evidence; IGF-1 LR3 is not FDA-approved and rated 1/5. Sermorelin has more human evidence behind it. Both are banned in sport by WADA. Both are used for growth hormone axis goals.
Sermorelin: Formerly FDA-approved (Geref) — discontinued 2008. IGF-1 LR3: Not FDA-approved. Regulations change, so confirm with the FDA.
Sermorelin is rated 4 out of 5: Human trials supported its former approval for pediatric GH deficiency. Evidence for adult anti-aging use is small and older. IGF-1 LR3 is rated 1 out of 5: Developed as a cell-culture reagent. No human clinical trials of LR3. Human data exists only for the approved native IGF-1 drug (mecasermin), a different product. The scale is explained on our methodology page.
Sermorelin is banned by WADA, by name or as part of a named class. IGF-1 LR3 is banned by WADA, by name or as part of a named class.