Tesamorelin vs CJC-1295
Tesamorelin and CJC-1295 are both synthetic analogues of human growth hormone-releasing hormone acting at the same pituitary receptor, which is why they are set against each other so often. Their positions in the literature are not equivalent. Tesamorelin was evaluated in multicentre randomised placebo-controlled trials with visceral adipose tissue as the primary endpoint and holds a marketing authorisation for HIV-associated lipodystrophy. CJC-1295 is two molecules under one name, a DAC-conjugated form that binds circulating albumin and a non-DAC form more accurately called modified GRF(1-29); its human record is a small set of phase I and phase II studies conducted between 2005 and 2009, all with the DAC form. One published experiment did administer both, but it was an anti-doping method-development study that injected each compound into rats to establish how long it remained detectable in plasma. Nothing has compared what the two compounds do.
They have been compared directly.
One published experiment administered both compounds, and it measured detectability rather than effect. Knoop and colleagues injected each of four growth hormone-releasing hormones, sermorelin, CJC-1293, CJC-1295 and tesamorelin, intravenously into rats, one compound per animal, and sampled plasma at two, four and eight hours in order to validate an immunoaffinity purification and mass spectrometry method for doping control. All four intact substances were detected at two hours, and tesamorelin, CJC-1295 and CJC-1293 were still identified at four and eight hours, while no anticipated metabolite was confirmed in the rodent samples. Nothing about growth hormone release, body composition or any other physiological endpoint was measured, so the study establishes a comparative detection window and nothing more. Every other publication that engages both compounds is either an anti-doping assay in which they appear as spiked reference analytes in urine, plasma or blood, or a narrative review that catalogues them within the GHRH analogue class. No trial has compared their effects in humans.
The 19 studies that tested both
- 01Animal in vivo2016
Qualitative identification of growth hormone-releasing hormones in human plasma by means of immunoaffinity purification and LC-HRMS/MS
Knoop A, et al. · Analytical and Bioanalytical Chemistry · anti-doping method validation with a rat elimination study; four GHRH analogues including tesamorelin and CJC-1295 administered intravenously, one compound per animal, plasma sampled at 2, 4 and 8 hours, plus an in vitro plasma stability arm and one human sermorelin sample
Each of the four analogues was administered intravenously to rats and plasma was screened for the intact drug and for anticipated metabolites. All four intact substances were detected two hours after dosing, and tesamorelin, CJC-1295 and CJC-1293 were also identified at four and eight hours, whereas sermorelin was not. No anticipated metabolite was confirmed in the rodent samples. The measured endpoint was analytical detectability for doping control; no pharmacological or physiological variable was recorded.
- 02In vitro2026
Analysis of growth hormone releasing hormone and its analogs in urine using nano liquid chromatography coupled with quadrupole/orbitrap mass spectrometry
Uçaktürk E, Nemutlu E · Journal of Pharmaceutical and Biomedical Analysis · human urine, analytical method development; both compounds handled as spiked reference analytes
A nano-LC quadrupole/Orbitrap mass spectrometry method was developed and validated for GHRH and its synthetic analogues, including sermorelin, tesamorelin and CJC-1295, in urine. Sample preparation combining ultrafiltration and solid-phase extraction achieved limits of detection at or below 0.5 ng/mL. Neither compound was administered.
- 03In vitro2024
Chromatographic-mass spectrometric analysis of peptidic analytes (2-10 kDa) in doping control urine samples
Thomas A, Walpurgis K, Thevis M · Journal of Mass Spectrometry · human doping control urine, multi-analyte initial testing procedure; both compounds included as target analytes
A single extraction and detection procedure was established for prohibited peptides of 2 to 10 kDa in urine, covering the growth hormone-releasing hormones sermorelin, CJC-1295 and tesamorelin together with their metabolites, alongside insulins, IGF-I analogues, synacthen, gonadorelin and mechano growth factors. Proof of principle was demonstrated on post-administration samples for insulins and gonadorelin rather than for either GHRH analogue.
- 04In vitro2023
Cationic exchange SPE combined with triple quadrupole UHPLC-MS/MS for detection of GHRHs in urine samples
Cristea CD, et al. · Analytical Biochemistry · human urine, anti-doping screening method; both compounds fortified into urine as reference standards
Weak cation exchange solid-phase extraction coupled to triple quadrupole UHPLC-MS/MS detected four synthetic GHRH analogues including tesamorelin and CJC-1295, alongside the endogenous releasing hormone, at limits of detection as low as 0.2 ng/mL. The validated approach was reported as suitable for routine anti-doping laboratory screening.
- 05In vitro2022
Probing for peptidic drugs (2-10 kDa) in doping control blood samples
Thomas A, et al. · Analytical Science Advances · doping control blood samples, generic mixed-mode solid-phase extraction; both compounds included as target analytes
A generic sample preparation for blood was shown to co-extract sermorelin, CJC-1295 and tesamorelin together with insulins, IGF-I analogues and mechano growth factors at criteria meeting World Anti-Doping Agency requirements. Proof of principle was provided by post-administration samples for synthetic insulin analogues; the GHRH analogues were present as spiked reference material.
- 06In vitro2022
An antibody-free, ultrafiltration-based assay for the detection of growth hormone-releasing hormones in urine at low pg/mL concentrations using nanoLC-HRMS/MS
Coppieters G, et al. · Journal of Pharmaceutical and Biomedical Analysis · human urine, antibody-free enrichment; both compounds spiked as analytes
An ultrafiltration-based preconcentration step replaced immunoaffinity purification and achieved detection limits of approximately 5 to 25 pg/mL for GHRH analogues including tesamorelin and CJC-1295 by nanoLC-HRMS/MS. Recoveries were improved relative to immunoaffinity workflows at reduced operational cost.
- 07In vitro2021
Advances in the detection of growth hormone releasing hormone synthetic analogs
Memdouh S, et al. · Drug Testing and Analysis · in vitro metabolism study; sermorelin, tesamorelin, CJC-1295 and the drug affinity complex variant treated as four distinct analytes
Nineteen major in vitro metabolites were identified and synthesised across the four GHRH analogues, with CJC-1295 and its drug affinity complex variant handled separately. The resulting LC-MS/MS methods addressed the absence of metabolism data for unapproved synthetic GHRH variants in urine analysis. The compounds were incubated rather than administered.
- 08In vitro2020
Comparison of magnetic bead surface functionalities for the immunopurification of growth hormone-releasing hormones prior to liquid chromatography-high resolution mass spectrometry
Pont L, et al. · Journal of Chromatography A · human urine, comparison of magnetic bead supports and affinity chemistries; both compounds present as spiked analytes
Magnetic beads with different supports, binding capacities and affinity chemistries were compared for immunopurification of the releasing hormone and its analogues sermorelin, tesamorelin and CJC-1295 before quadrupole-Orbitrap analysis. The optimised method was fully validated, with a limit of detection of 0.2 ng/mL and a limit of identification of 0.5 ng/mL.
- 09In vitro2015
Expanded test method for peptides >2 kDa employing immunoaffinity purification and LC-HRMS/MS
Thomas A, et al. · Drug Testing and Analysis · human blood and urine, combined initial test method; both compounds listed among the growth hormone-releasing hormones covered
An immunoaffinity purification and LC-HRMS/MS procedure was extended to bioactive peptides above 2 kDa, listing sermorelin, CJC-1293, CJC-1295 and tesamorelin among the growth hormone-releasing hormones covered alongside insulins, synthetic ACTH, IGF-I and mechano growth factors. Proof of principle came from administration study samples for insulins and synacthen, not for the GHRH analogues.
- 10Review2026
The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration
Dominikowski A, et al. · Frontiers in Endocrinology · narrative review of peptides acting on the GH-IGF-1 axis; both compounds discussed, neither administered
The review surveyed unregulated peptides marketed as research compounds that act on the GH-IGF-1 axis, including GHRH analogues such as tesamorelin and CJC-1295, and proposed a clinically oriented assessment algorithm for evaluating patients who self-administer them. The authors documented substantial uncertainty in the efficacy and safety data available for the unapproved compounds in the group.
- 11Review2026
Injectable Peptides in Sports Medicine: A Structured Narrative Review of Evidence, Safety, and Antidoping Implications
Villegas Meza AD, et al. · JBJS Reviews · structured narrative review of injectable peptides published between 2020 and 2025; both compounds named, neither administered
The review classified injectable peptides into five functional classes and found that only glucagon-like peptide-1 agonists carried reproducible randomised evidence for a musculoskeletal indication. GH-axis agents including the GHRH analogues were categorised as experimental, and use was recommended to be confined to approved agents and formal research protocols.
- 12Review2026
Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance
Mendias CL, Awan TM · Sports Medicine · narrative review contrasting approved and unapproved peptide therapies; both compounds named, neither administered
The review contrasted regulator-approved peptide drugs with a parallel market of unapproved compounds used in sports medicine, covering mechanisms, safety and regulatory status. The authors reported that although animal models suggested activity for several agents, rigorous human safety data remained scarce for most unapproved peptides.
- 13Review2026
Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians
Mayfield CK, et al. · The American Journal of Sports Medicine · primer-style review of commonly encountered injectable peptides; both compounds named, neither administered
The primer described the injectable peptides most often encountered in orthopaedic and sports medicine practice, including the GHRH analogue class to which both compounds belong. It reported that human orthopaedic outcome data remained largely absent despite preclinical signals, and concluded that further safety and efficacy research was required.
- 14Review2026
Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions
Rahman OF, Lee SJ, Seeds WA · JAAOS Global Research & Reviews · narrative review of therapeutic peptides in orthopaedics; both compounds grouped as growth hormone secretagogues, neither administered
The review grouped ipamorelin, CJC-1295, tesamorelin, sermorelin and AOD-9604 together as growth hormone secretagogues described as acting through IGF-1 signalling and satellite cell repair, and set that group alongside wound-healing, recovery and neuroactive peptide classes. No distinction in evidence quality between individual members of the group was drawn.
- 15Review2026
Therapeutic Peptides in Aesthetic, Metabolic and Endocrine Conditions: Effects, Safety, Clinical Applications, and Future Perspectives
Renke G, Chinellato L · International Journal of Molecular Sciences · literature review of 106 articles on therapeutic peptides; both compounds named as GHRH analogues, neither administered
The review listed CJC-1295, sermorelin and tesamorelin together as GHRH analogues that amplify pulsatile growth hormone secretion, noting that CJC-1295 carries a drug affinity complex modification extending its half-life to roughly one week and that tesamorelin is approved for HIV-associated lipodystrophy because it reduces visceral fat. The authors concluded that further study was required before most newer peptides could be considered safe for human use.
- 16Review2015
Transmembrane signal transduction by peptide hormones via family B G protein-coupled receptors
Culhane KJ, et al. · Frontiers in Pharmacology · mechanistic review of family B G protein-coupled receptor activation; both compounds listed as drugs acting at the GHRH receptor
The review catalogued the fifteen family B G protein-coupled receptors with their endogenous ligands, associated diseases and drugs, listing tesamorelin, sermorelin and CJC-1295 together as agents acting at the growth hormone-releasing hormone receptor in dwarfism and HIV-related lipodystrophy. It addressed the structural basis of receptor activation rather than differences between the individual drugs.
- 17Review2026
Recent Developments in Capillary and Microchip Electroseparations of Peptides (2023-mid 2025)
Kašička V · Electrophoresis · review of capillary and microchip electromigration methods for peptide analysis published between 2023 and mid-2025; both compounds appear as analytes in a separation
The review reproduced a chiral capillary zone electrophoresis separation of four growth hormone-releasing hormone analogues, tesamorelin, CJC-1293, CJC-1295 and sermorelin, achieved with a dimethyl-beta-cyclodextrin selector in a lithium phosphate background electrolyte. The compounds featured as analytes in a separation method, with no biological endpoint involved.
- 18Review2026
Annual Banned-Substance Review 18th Edition-Analytical Approaches in Human Sports Drug Testing 2024/2025
Thevis M, Kuuranne T, Geyer H · Drug Testing and Analysis · annual survey of analytical approaches in human sports drug testing, covering literature published between October 2024 and September 2025
The review listed both compounds together within the World Anti-Doping Agency category of growth hormone releasing factors, alongside CJC-1293 and sermorelin, and surveyed the detection methods published for that class during the review period. Its subject was analytical detection rather than pharmacological effect.
- 19Review2025
Annual Banned-Substance Review 17th Edition-Analytical Approaches in Human Sports Drug Testing 2023/2024
Thevis M, Kuuranne T, Geyer H · Drug Testing and Analysis · annual survey of analytical approaches in human sports drug testing, covering literature published between October 2023 and September 2024
The review grouped both compounds within the prohibited growth hormone releasing factors and summarised a urine test method reported during the period that targeted four synthetic releasing hormones, tesamorelin and CJC-1295 among them, together with the endogenous hormone. It reported that releasing factors and secretagogues continued to attract analytical attention.
Side by side.
| Tesamorelin | CJC-1295 | |
|---|---|---|
| Evidence maturity | Approved drug | Early clinical |
| Studies cited here | 15 | 16 |
| Published 2023 or later | 11 | 8 |
| Newest paper | 2026 | 2026 |
| Sequence and origin | A synthetic analogue of human growth hormone-releasing hormone carrying a hexenoyl modification on the N-terminal tyrosine residue, which slows enzymatic degradation of the peptide itself. | Built on the N-terminal 29-amino-acid fragment of the same releasing hormone, with backbone substitutions that resist dipeptidyl peptidase-IV cleavage. The DAC form adds a maleimidopropionyl linker forming a covalent complex with circulating albumin. |
| How duration of action is engineered | Through resistance to enzymatic degradation conferred by the terminal modification, with no carrier molecule involved. The compound stimulates endogenous, pulsatile growth hormone secretion. | Through albumin binding in the DAC form, reported to extend the plasma half-life to roughly one to two weeks with sustained GH and IGF-1 elevation. The non-DAC form has no carrier and a short duration comparable to sermorelin. |
| Regulatory status | Approved for HIV-associated lipodystrophy and classified in this library as an approved drug, while also prohibited in sport as a growth hormone releasing factor. | No marketing authorisation in any jurisdiction, for either form. It appears on the World Anti-Doping Agency Prohibited List, and most literature published since 2019 concerns detection rather than clinical use. |
| Size and design of the human evidence | Multicentre randomised placebo-controlled trials, including a 412-participant trial in HIV and abdominal fat accumulation and a 61-participant trial in HIV-associated fatty liver disease, with 2026 meta-analyses pooling four and five randomised trials. | A small number of phase I and phase II studies conducted between 2005 and 2009, all with the DAC-conjugated form. No peer-reviewed randomised controlled trial of the non-DAC modified GRF(1-29) form was identified. |
| Endpoints the human studies measured | Imaging and clinical measures: visceral adipose tissue, hepatic fat fraction, lean body mass, waist circumference and cognitive test performance, with adverse events recorded alongside them. | Endocrine surrogates only: growth hormone and IGF-1 concentrations, how long those elevations persisted, whether secretion remained pulsatile, and serum protein profile changes. No clinical outcome endpoint has been tested. |
| Whether the studied molecule matches the marketed one | It does. The trials that support the approval used the same analogue that carries it. | Not reliably. Essentially all human data pertain to the DAC-conjugated compound, whereas material sold and described under the CJC-1295 name frequently refers to the non-DAC modified GRF(1-29), which has no randomised human trial. |
| Where the contemporary literature sits | Clinical. Recent output includes a randomised trial in people with HIV on integrase inhibitors, two 2026 meta-analyses of the lipodystrophy trials, a published protocol for an exercise-adjunct trial, and preclinical GHRH-agonist neurobiology. | Analytical. Recent output is dominated by LC-MS/MS, nanoLC-HRMS/MS and capillary electrophoresis methods for detecting the compound in urine, plasma, blood and equine samples, plus narrative reviews of unapproved peptide use. |
| Safety signals reported | Meta-analyses of the randomised trials recorded arthralgia, myalgia and paraesthesia, higher discontinuation rates in the treatment arms, and growth hormone-related adverse effects, with glucose homeostasis and IGF-1 elevation identified as monitoring concerns. | None established either way. Long-term safety, glucose tolerance during sustained IGF-1 elevation and any clinical outcome endpoint remain unstudied for both forms, so the safety record is absent rather than reassuring. |
And what it does not.
One experiment administered both compounds, and it was a doping-control method validation in rats that measured how long each remained detectable in plasma. It reported that tesamorelin and CJC-1295 were both still identifiable eight hours after injection while sermorelin was not, which is a statement about analytical detection windows and not about what either compound does in a body. Beyond that experiment the two evidence bases are not comparable in kind. Tesamorelin has multicentre randomised placebo-controlled trials with imaging endpoints, a marketing authorisation resting on them and continuing clinical research, although its controlled evidence sits almost entirely within HIV-associated lipodystrophy and hepatic steatosis. CJC-1295 has a handful of phase I and phase II studies from 2005 to 2009, all conducted with the DAC-conjugated form, all measuring endocrine surrogates rather than any clinical outcome, and none addressing the non-DAC form most often sold under the name. No published work compares the two on efficacy, safety or dose-response in humans.
Common questions.
- What was the one experiment that administered both compounds actually testing?
Analytical detectability. The study was an anti-doping method validation: four growth hormone-releasing hormones, including tesamorelin and CJC-1295, were injected intravenously into rats, one compound per animal, and plasma was analysed by immunoaffinity purification and mass spectrometry. All four intact substances were found two hours after dosing, and tesamorelin, CJC-1295 and CJC-1293 were still identified at four and eight hours. No growth hormone measurement, body composition measure or other physiological endpoint was taken, so the work supports no comparative claim about effect.
- Which of the two holds a marketing authorisation?
Tesamorelin. It was approved for HIV-associated lipodystrophy after multicentre randomised placebo-controlled trials that used visceral adipose tissue as the primary endpoint. CJC-1295 has no marketing authorisation in any jurisdiction, in either the DAC-conjugated or the non-DAC form, and appears on the World Anti-Doping Agency Prohibited List. That difference explains most of the asymmetry between the two literatures: one compound accumulated trials because a sponsor pursued an indication, the other accumulated detection methods because regulators pursued its misuse.
- Did the human studies of the two compounds measure the same kind of endpoint?
No, and that is the main obstacle to comparing them. The tesamorelin trials measured imaging and clinical outcomes, including visceral adipose tissue, hepatic fat fraction, lean body mass, waist circumference and cognitive test performance, in defined patient populations. The CJC-1295 studies measured endocrine surrogates only: growth hormone and IGF-1 concentrations, how long those elevations lasted, whether secretion remained pulsatile, and serum protein profile changes in healthy adults. A surrogate result and a clinical result cannot be ranked against one another.
- Why do so many anti-doping papers name both compounds?
Because growth hormone releasing factors are prohibited in sport at all times, and laboratories need one procedure that captures the whole class. Published methods therefore treat sermorelin, CJC-1293, CJC-1295 and tesamorelin as a group of target analytes, spiking them into urine, plasma or blood to validate extraction, recovery and limits of detection. Nine such papers name both compounds. Between them they establish that both can be detected at low picogram to nanogram concentrations, which says nothing at all about efficacy.
- Is the CJC-1295 sold as a research chemical the molecule that was studied in humans?
Often it is not. The phase I and phase II studies conducted between 2005 and 2009 used the DAC-conjugated compound, which binds albumin covalently and produced sustained growth hormone and IGF-1 elevation. Material sold and described under the CJC-1295 name frequently refers to the non-DAC form, more accurately called modified GRF(1-29), which retains only the backbone modifications resisting dipeptidyl peptidase-IV cleavage and has a short duration comparable to sermorelin. No peer-reviewed randomised controlled trial of that form was identified.
For research purposes only. Not for human consumption, diagnosis, treatment, or prevention of any condition. Nothing on this page is medical advice, and no comparison here should be read as a recommendation of either compound.