IGF-1 LR3 and tesamorelin are searched together because both are sold around the same promise — more of the growth-hormone axis's end product, IGF-1. They reach it by opposite routes and stand at opposite ends of the evidence. Tesamorelin is an approved drug that makes the pituitary release growth hormone, with a label, trials and a measured IGF-1 rise. IGF-1 LR3 is an engineered IGF-1 analogue that skips the pituitary entirely and has never been given to a person in a published study. This page sets the two records side by side (read 2026-10-11), shows why direct IGF-1 and a GHRH analogue pull the pituitary in different directions, and does the syringe arithmetic. It compares; it recommends neither.
The single-compound records are on the IGF-1 LR3 and tesamorelin dosage pages; tesamorelin's other comparisons include AOD-9604 vs tesamorelin and tesamorelin vs ipamorelin. The same analogue against the unlabelled, long-acting GHRH analogue is on CJC-1295 vs IGF-1 LR3.
Side by side
| IGF-1 LR3 | Tesamorelin | |
|---|---|---|
| What it is | IGF-1 analogue (Arg3, N-terminal extension) | Analogue of growth-hormone-releasing hormone |
| Where it acts | IGF-1 receptor, directly | GHRH receptor in the pituitary → GH → IGF-1 |
| Label | None anywhere | EGRIFTA WR 1.28 mg daily; EGRIFTA SV 1.4 mg daily |
| Human doses on record | None | Subcutaneous 1–2 mg daily |
| Figures circulating | 20–40 mcg a day (2026 review); 20–100 mcg (this site's chart) | Forum figure 2 mg a day (2026 review) |
| Registered trials (2026-10-11) | 0 | 24 |
| 2026 review evidence tier | D — no peer-reviewed human studies | A — RCTs in an approved indication |
| WADA 2026 | S2.3, IGF-1 analogues | S2.2.4, by name |
Opposite directions on one axis
Tesamorelin works upstream. It binds the GHRH receptor, the pituitary releases growth hormone in pulses, and the liver makes IGF-1. The size of that answer is on the EGRIFTA WR label: IGF-1 up 107 and 108 ng/mL over 26 weeks in the two pivotal trials, against −15 and +3 on placebo. The label asks for IGF-1 to be monitored because the rise is the mechanism.
IGF-1 LR3 enters at the bottom. It was built to bind the IGF binding proteins weakly and the receptor strongly, so it acts without the pituitary. The body treats rising IGF-1 as a signal to release less growth hormone, and the one controlled human measurement of that feedback is clear: in Roche's 2017 volunteer study, recombinant IGF-I at 50 mcg/kg twice daily for four days almost completely suppressed growth-hormone secretion. That study used native IGF-I, not the LR3 analogue, and no study has measured the analogue's effect on growth hormone in people. What the record supports is the direction: a GHRH analogue pushes the pituitary to release growth hormone; direct IGF-1 was observed to switch it off.
Two different glucose signals
The EGRIFTA WR label lists glucose intolerance as a warning: 5% of treated patients reached an HbA1c of 6.5% or more by week 26, against 1% on placebo, because growth hormone opposes insulin. IGF-1 acts the other way, with insulin-like effects; the 2026 review notes reports of low-blood-sugar symptoms among IGF-1 LR3 users, while describing them as largely non-clinical. The two compounds' reported metabolic signals point in opposite directions — one measured in trials, the other anecdotal.
A milligram against a few micrograms
| Amount | Ratio to 1.28 mg tesamorelin, by mass |
|---|---|
| IGF-1 LR3 20 mcg | 1 : 64 |
| IGF-1 LR3 40 mcg | 1 : 32 |
| IGF-1 LR3 100 mcg (upper chart figure) | 1 : 12.8 |
Mass is not potency: the two act on different receptors, and only tesamorelin's dose comes from a trial. The ratio matters for the syringe, because microgram amounts from a milligram vial land on very few unit marks.
Each figure as syringe units
| Amount | IGF-1 LR3 1 mg in 1 mL (1,000 mcg/mL) | IGF-1 LR3 1 mg in 2 mL (500 mcg/mL) | Tesamorelin 10 mg in 2 mL (5 mg/mL) | EGRIFTA WR (8 mg/mL) |
|---|---|---|---|---|
| 20 mcg | 2 units | 4 units | — | — |
| 40 mcg | 4 units | 8 units | — | — |
| 100 mcg | 10 units | 20 units | — | — |
| 1.28 mg | — | — | 25.6 units | 16 units (label: 0.16 mL) |
| 1.4 mg | — | — | 28 units | — |
| 2 mg | — | — | 40 units | — |
Stated as results: at 1,000 mcg/mL, 20 mcg of IGF-1 LR3 is 2 units, where a one-unit misreading is half the amount; at 5 mg/mL, 1.28 mg of tesamorelin is 25.6 units. The EGRIFTA WR figure is the label's own; the research-vial figures assume the water volume equals the final volume, which the label shows is not exactly true for a large powder mass (the tesamorelin calculator explains the difference). The 0.1 mg and 1 mg vial arithmetic works the small vials, and insulin syringe units shows how low unit counts read on each barrel.
What is not established
Nothing compares the two, combines them, or gives IGF-1 LR3 to people. Tesamorelin's evidence is in one population, adults with HIV and abdominal fat accumulation; its label calls it weight neutral and does not establish long-term cardiovascular safety. What is sold as IGF-1 LR3 has been found, in published laboratory analyses recorded on this site's IGF-1 LR3 page, to differ from the named molecule. Product and dose decisions belong with a prescriber. The compounds are covered in Medibact's IGF-1 LR3 guide and Tesamorelin guide.
Sources and dates
Opened 2026-10-11: the EGRIFTA WR label record on openFDA (set id 839334d3-8c1d-4c26-9036-2ab524a6ea75, effective 2026-07-29), sections 1–3; the 2026 review by Dominikowski et al. (PMC13322892), tables 1 and 2; the abstract of Kletzl et al. 2017 (PMID 28110155); ClinicalTrials.gov counts for tesamorelin (24) and IGF-1 LR3 (0); a PubMed search for the LR3 name forms (116 records, no human administration among those read on this site's IGF-1 LR3 page); the 2026 WADA Prohibited List in Tractatenblad 2026 no. 25, S2.2.4 and S2.3. Carried from this site's pages with their read dates: the EGRIFTA WR IGF-1 and HbA1c figures (AOD-9604 vs tesamorelin, 2026-10-07), the EGRIFTA SV dose (tesamorelin page, 2026-09-18), the IGF-1 LR3 structure and black-market analyses (IGF-1 LR3 page, 2026-09-20). Ratios and units by this site. Corrections go to the contact page.