CJC-1295 and IGF-1 LR3 are searched as alternatives, but they are not two versions of one thing. They sit at either end of the same hormonal chain: CJC-1295 tells the pituitary to release growth hormone, which then drives the liver to make IGF-1; IGF-1 LR3 is itself an IGF-1 analogue, built to reach the IGF-1 receptor directly. One of them has been injected into people in published trials, and the measured result of those trials is a rise in IGF-1. The other has never been given to a person in a published study. This page sets the two side by side by what can be checked (all sources re-read 2026-10-17) and converts the circulating figures into syringe units. It reports; it suggests no dose.
The full record for each is on CJC-1295 dosage and IGF-1 LR3 dosage; the difference between the two CJC-1295 forms is on CJC-1295 with or without DAC.
Side by side
| CJC-1295 | IGF-1 LR3 | |
|---|---|---|
| What it is | 29-amino-acid GHRH analogue; sold with DAC (albumin-binding) or without (Mod GRF 1-29) | IGF-1 analogue: arginine at position 3 plus a 13-residue N-terminal extension |
| Where it acts | GHRH receptor in the pituitary → growth hormone → IGF-1 from the liver | IGF-1 receptor, directly |
| Published human studies | Two for the DAC form (2006); none for no-DAC | None |
| 2026 review evidence tier | B with DAC; D without | D |
| Registry records (ClinicalTrials.gov, 2026-10-17) | 1, terminated (NCT00267527) | 0 |
| PubMed, title or abstract (2026-10-17) | 35 records | 3 records also naming CJC-1295; none dosing either in people together |
| Label anywhere | None | None (mecasermin, recombinant IGF-1, is a different molecule) |
| WADA 2026 | S2.2.4, by name | S2.3, "IGF-1 … and its analogues" |
Upstream and downstream
The most useful fact for comparing them is the one the CJC-1295 trials measured. In Teichman 2006, single subcutaneous doses of CJC-1295 with DAC raised mean growth hormone 2- to 10-fold for six days or more and mean IGF-1 1.5- to 3-fold for 9 to 11 days; after repeated doses IGF-1 stayed above baseline for up to 28 days. Ionescu and Frohman found that a week after 60 or 90 mcg/kg, growth-hormone pulses kept their normal frequency and size while the trough between pulses rose 7.5-fold, and mean IGF-1 was 45% higher. The two doses did not differ.
So the effect of CJC-1295 that has been measured in people is a rise in the body's own IGF-1, within the limits the liver sets. IGF-1 LR3 is designed differently: the 2025 fetal-sheep paper cited on the IGF-1 LR3 page describes it as binding the IGF binding proteins weakly and the receptor strongly, which is the reason it was made for cell culture. Whether that makes it behave like the IGF-1 rise CJC-1295 produces, or something quite different, has not been measured in a person.
The record, by form
| Form | Human dosing on record | What the 2026 review says |
|---|---|---|
| CJC-1295 with DAC | 30, 60 and 90 mcg/kg subcutaneously, single and repeated (two 2006 trials) | Tier B: phase 1 PK/PD in healthy adults, no controlled efficacy data |
| CJC-1295 without DAC | None | Tier D: "essentially uncharacterised in the peer-reviewed human literature" |
| IGF-1 LR3 | None | Tier D: "no peer-reviewed clinical studies in humans have reported the route of administration; t½ not documented" |
The review also states that FDA placed CJC-1295 in Category 2 of its bulk-substance list "due to vasodilatatory reactions and tachycardia reports"; FDA's page, opened later on 2026-10-17 (content current 2026-04-22), now lists CJC-1295 among substances previously in Category 2 whose nominations were withdrawn. At 70 kg, the trial doses of 30 to 90 mcg/kg are 2.1 to 6.3 mg per injection — at or above the whole weekly total circulating online.
The figures in circulation
The 2026 review tabulates self-reported online patterns, labelled as "anthropological/behavioural data" and not as doses:
| Compound | Online pattern (review, Table 2) | Per week |
|---|---|---|
| CJC-1295 with DAC | 1–2 mg a week in 1–2 injections; 8–16-week cycles | 1–2 mg |
| CJC-1295 without DAC | 100–200 mcg per injection, 1–2 times a day | 0.7–2.8 mg |
| IGF-1 LR3 | 20–40 mcg a day; 4–6 weeks on, equal time off | 0.14–0.28 mg |
By mass, the weekly CJC-1295 figures are roughly 3.6 to 14 times (with DAC) and 2.5 to 20 times (without) the weekly IGF-1 LR3 figure. That is a comparison of milligrams only: the molecules differ in size, act at different points and have different half-lives, so a milligram of one says nothing about the effect of a milligram of the other. This site's IGF-1 LR3 page records 20 to 100 mcg a day in its chart, from vendor pages read on 2026-09-18.
Both in syringe units
CJC-1295 vials are labelled 5 mg and 10 mg; IGF-1 LR3 vials 0.1 mg and 1 mg. On a U-100 syringe, units = amount ÷ concentration × 100.
| Vial and water | Concentration | mcg per unit | 20 mcg | 40 mcg | 100 mcg | 1 mg | 2 mg |
|---|---|---|---|---|---|---|---|
| IGF-1 LR3 0.1 mg in 1 mL | 100 mcg/mL | 1 | 20 units | 40 | 100 | — | — |
| IGF-1 LR3 1 mg in 1 mL | 1,000 mcg/mL | 10 | 2 units | 4 | 10 | — | — |
| IGF-1 LR3 1 mg in 2 mL | 500 mcg/mL | 5 | 4 units | 8 | 20 | — | — |
| CJC-1295 5 mg in 2 mL | 2.5 mg/mL | 25 | — | — | 4 units | 40 | 80 |
| CJC-1295 5 mg in 1 mL or 10 mg in 2 mL | 5 mg/mL | 50 | — | — | 2 units | 20 | 40 |
| CJC-1295 10 mg in 1 mL | 10 mg/mL | 100 | — | — | 1 unit | 10 | 20 |
The scales barely overlap. An IGF-1 LR3 amount at 1,000 mcg/mL sits on the first few marks of the syringe, where one unit is 10 mcg and a misread mark is a quarter of a 40 mcg amount; a CJC-1295 with DAC amount at 2.5 mg/mL fills most of the barrel. The 100 mcg column is the only place both appear: the no-DAC CJC-1295 figure and the top of the IGF-1 LR3 chart range. Other combinations are worked by the IGF-1 LR3 vial arithmetic and the CJC-1295 calculator.
What is not established
Neither compound is approved anywhere. IGF-1 LR3 and the no-DAC form of CJC-1295 have no published human study at all; the DAC form has two short studies in healthy adults and no efficacy trial. No study has given the two together, and the fact that both act on the growth-hormone–IGF-1 axis gives no basis for predicting what a combination would do. The figures in circulation are conventions without a source. Medibact's CJC-1295 guide and IGF-1 LR3 guide cover each compound. Decisions about either belong with a clinician.
Sources and dates
Opened 2026-10-17: PubMed abstracts through NCBI E-utilities for PMIDs 16352683 (Teichman 2006), 17018654 (Ionescu and Frohman 2006), 38197510 and 26382721 (doping-control methods naming both), and the PubMed counts for CJC-1295 (35) and for both together (3); the full text of Dominikowski et al., Frontiers in Endocrinology 2026 (PMID 42395176, PMC13322892), Table 1 (evidence tiers) and Table 2 (online patterns); PubChem CID 91971820 (CJC-1295, C165H269N47O46, 3,647.2); ClinicalTrials.gov v2 API searches for CJC-1295 (1 record) and IGF-1 LR3 (0); the 2026 Prohibited List text in Tractatenblad 2026 no. 25. From this site's compound pages (opened 2026-09-18 and 2026-09-20): the IGF-1 LR3 structure and the vendor figures. fda.gov did not answer on 2026-10-17. Mass and unit arithmetic by this site. Corrections go to the contact page.