Peptide basics
There is no evidence comparison to make between these two
On this page
Neither compound has a registered human trial naming it as an intervention. Both counts are zero.
IGF-1 LR3 has 10 indexed publications. IGF-1 DES has none that our phrase search finds.
Neither has an FDA-approved product. A related molecule, mecasermin, is approved — but it is a different thing.
So there is no evidential basis for preferring one over the other, and any source that offers one is not drawing on the public record.
This page reports what registered human evidence exists for two IGF-1 analogues. The answer is none for both. Nothing here is a recommendation and no dose, schedule or route appears.
What the record holds
For IGF-1 LR3 the registry returns no study that administered it to human participants. For IGF-1 DES the same. Both compounds therefore have no phase, no enrolment and no posted result.12
The literature is nearly as thin. IGF-1 LR3 has 10 indexed publications over ten years; our phrase search for IGF-1 DES finds none, which usually indicates a compound whose name varies too much to match reliably rather than one nobody has ever written about.12
The approved relative is not a substitute
Mecasermin is an approved recombinant IGF-1 product with a regulatory record behind it. It is sometimes invoked in discussions of these analogues, and it should not be: an approval attaches to a specific molecule and a specific product.3
LR3 and DES are deliberately modified versions built to behave differently from native IGF-1. That is the point of making them, and it is also exactly why evidence about the unmodified molecule does not transfer.3
Why publish an empty comparison
Because the comparison is made constantly elsewhere, in detail, with confident distinctions about how each behaves. Someone searching for it deserves to find the actual state of the record rather than only the confident version.12
An empty record is a finding. It does not mean the compounds do nothing; it means nobody has run the study that would tell you, and that no amount of forum consensus substitutes for one.12
Common questions
Are there animal studies?
There is animal and laboratory work on IGF-1 analogues generally. It establishes mechanism and cannot establish what happens in people, which is what a trial is for.
Why does IGF-1 DES show zero publications?
Most likely a naming problem — the compound is written several ways and a phrase search matches none of them consistently. A zero here means no public record found, not proof of none.
Does the FDA approval of mecasermin make these safer?
No. Approvals do not extend to modified versions of a molecule, and the modifications are precisely what make these different compounds.
Sources
- RegulatoryClinicalTrials.gov search — intervention: IGF-1 LR3U.S. National Library of Medicine, 2026clinicaltrials.gov/search?intr=IGF-1+LR3 ↗↩ Back to text
- RegulatoryClinicalTrials.gov search — intervention: IGF-1 DESU.S. National Library of Medicine, 2026clinicaltrials.gov/search?intr=IGF-1+DES ↗↩ Back to text
- RegulatoryDrugs@FDA — mecasermin approval recordU.S. Food and Drug Administration, 2026www.accessdata.fda.gov/scripts/cder/daf/ ↗↩ Back to text