Tesamorelin vs CJC-1295
Research Comparison

Research Overview

Tesamorelin and CJC-1295 are both synthetic analogs of growth hormone-releasing hormone (GHRH), the hypothalamic peptide that signals the pituitary to release growth hormone (GH). Tesamorelin keeps all 44 residues of human GHRH and adds a trans-3-hexenoyl group at the amino terminus (Ferdinandi et al., 2007). CJC-1295 keeps the first 29 residues with four substitutions and, in its drug affinity complex (DAC) form, adds a lysine whose maleimide group bonds to serum albumin (Jetté et al., 2005).

Their research records differ as much as their structures, so tesamorelin vs CJC-1295 is about evidence as much as chemistry. Disguised Alpha supplies tesamorelin (5MG or 10MG), CJC-1295 No DAC (10MG) and CJC-1295 with DAC (5MG) as lyophilized powders for laboratory research use only.

Structure and Class

Native GHRH is fragile: plasma clips its first two residues, leaving a fragment with under one thousandth of the activity, and intact GHRH(1-44) disappeared with a half-life of 6.8 minutes in healthy volunteers (Frohman et al., 1986).

Tesamorelin's trans-3-hexenoyl group on tyrosine 1 made the peptide resistant to dipeptidyl aminopeptidase-IV and slowed its breakdown in rat, dog and human plasma (Ferdinandi et al., 2007); the rest is native GHRH(1-44) amide, including asparagine 8 and methionine 27. Product page identity: C221H366N72O67S, 5135.86 g/mol.

CJC-1295 shortens the chain to residues 1 to 29 and substitutes D-alanine at 2, glutamine at 8, alanine at 15 and leucine at 27, with an amidated C-terminus; the named compound adds a C-terminal lysine carrying a 3-maleimidopropionamide group (Jetté et al., 2005). In healthy men, D-alanine at position 2 alone roughly halved clearance of the 1-29 fragment and lengthened its disappearance half-time from 4.3 to 6.7 minutes (Soule et al., 1994). No DAC: C152H252N44O42, 3367.9 g/mol. With DAC: C165H269N47O46, 3647.06 g/mol on the product page in PubChem.

Because the CJC-1295 name covers both forms, identify material by formula, molecular weight and the identity printed on the lot certificate.

Side by Side

Research Context: Tesamorelin

Developed as TH9507, tesamorelin raised plasma GH and IGF-1 in pigs, rats and dogs on daily repeat exposure; its apparent elimination half-life in dogs was 21 to 45 minutes, and reversible adverse findings in dogs were attributed to sustained supraphysiological GH and IGF-1 (Ferdinandi et al., 2007). Models: pigs, rats and dogs.

In 13 healthy men studied across two weeks of once-daily exposure, it increased mean overnight GH, GH peak area and basal secretion and raised IGF-I, and the authors concluded it augments basal and pulsatile secretion (Stanley et al., 2011). A 2026 review lists a human half-life of about 26 to 38 minutes (Dominikowski et al., 2026). Model: healthy men.

The first phase 3 trial, in 412 adults with HIV and abdominal fat accumulation, reported a 15.2% decrease in visceral adipose tissue on CT over 26 weeks against a 5.0% increase with placebo; adverse events did not differ significantly between groups, though more tesamorelin participants withdrew because of one (Falutz et al., 2007). In November 2010 the FDA approved a pharmaceutical tesamorelin product for one indication, excess abdominal fat in HIV-infected adults with lipodystrophy (Grunfeld et al., 2011). That approval covers that drug product only; Disguised Alpha's tesamorelin is research material, not that product.

Research Context: CJC-1295

In the original study, albumin conjugates of three maleimido derivatives resisted dipeptidylpeptidase-IV and stayed active in cultured rat pituitary cells; in rats, CJC-1295 quadrupled GH area under the curve over two hours versus the unmodified fragment and remained in plasma beyond 72 hours (Jetté et al., 2005). Models: rat cells and rats.

Human data exist only for the DAC form. In two randomized, placebo-controlled, ascending-amount trials in healthy adults, one exposure raised mean GH two to ten fold for six days or more and IGF-I 1.5 to three fold for 9 to 11 days; the estimated half-life was 5.8 to 8.1 days (Teichman et al., 2006). Overnight sampling a week after one exposure found GH pulse frequency and magnitude unaltered while trough GH rose 7.5 fold (Ionescu and Frohman, 2006). Model: healthy adults.

The No DAC form has no peer-reviewed human studies and no reported human half-life; claims about its pulsatile action are extrapolated mainly from the unmodified 1-29 fragment (Dominikowski et al., 2026).

ClinicalTrials.gov lists one CJC-1295 study: a 12-week, placebo-controlled phase 2 trial in adults with HIV-associated visceral obesity, sponsored by the developer, ConjuChem (NCT00267527). It is listed as terminated, with a 2006 completion date and no stated reason or posted findings. Neither form has been approved by the FDA or the EMA (Dominikowski et al., 2026). An FDA page on bulk drug substances that may present significant safety risks lists CJC-1295 among former category 2 substances whose nominations were withdrawn; its entry notes serious adverse events, including increased heart rate and systemic vasodilatory reaction, and limited clinical data.

Choosing Between Them for a Research Question

Choosing tesamorelin or CJC-1295 starts with the time course a question needs. Tesamorelin is cleared in minutes, so each exposure is a discrete stimulus and sustained designs need repeated exposure. CJC-1295 with DAC is a multi-day stimulus, and IGF-I stayed above baseline up to 28 days after repeated exposure (Teichman et al., 2006), so crossover designs need washouts measured in weeks. The No DAC form suits short-exposure designs but has no measured human profile.

Tesamorelin fits questions about the full-length sequence, amino-terminal acylation or a published human reference profile; the DAC form fits sustained stimulation and albumin conjugation; the No DAC form isolates the substituted 1-29 core. Tesamorelin against No DAC changes length, four residues and the terminal protection at once, so a difference cannot be pinned to one change.

Plan arms in moles: one milligram holds about 0.19 µmol of tesamorelin, 0.30 µmol of No DAC and 0.27 µmol of the DAC form. For analytical work, one study synthesized 19 in vitro metabolites of sermorelin, tesamorelin and both CJC-1295 forms as reference materials for a urine detection method (Memdouh et al., 2021).

Handling and Storage

All three ship lyophilized, and their product pages list -20°C for the powder as shipped and 2 to 8°C after reconstitution, protected from light, with freeze/thaw cycles avoided. Let the sealed vial reach room temperature before opening, add diluent slowly down the wall, and swirl rather than shake.

Tesamorelin can cloud or gel in near-neutral, unbuffered diluents and at high concentration (see our tesamorelin gelling note), and its methionine 27 oxidizes readily, so limit air, light and oxidizers. The DAC maleimide reacts with free thiols and hydrolyzes in water over time, so keep thiol reagents, albumin and serum out of its stock unless conjugation is the experiment. Aliquot, record the lot number, and use the measured content from the COA portal, not the label mass.

Questions Researchers Ask

Tesamorelin vs CJC-1295: what is the difference?

Both are GHRH analogs. Tesamorelin is the full 44-residue hormone with an N-terminal hexenoyl group (Ferdinandi et al., 2007); CJC-1295 is a substituted 29-residue fragment, with or without an albumin-binding lysine (Jetté et al., 2005). Reported half-lives run from minutes for tesamorelin to 5.8 to 8.1 days for CJC-1295 with DAC (Teichman et al., 2006).

CJC-1295 vs tesamorelin: which has more human research?

Tesamorelin. A 2026 review placed it in tier A, with randomized trials, CJC-1295 with DAC in tier B, with phase 1 data in healthy adults, and the No DAC form in tier D, with no peer-reviewed human studies (Dominikowski et al., 2026).

Does either compound flatten pulsatile GH release?

Not where it was measured: tesamorelin raised peak area and basal secretion (Stanley et al., 2011), and CJC-1295 with DAC left pulse frequency and magnitude unchanged while raising trough levels (Ionescu and Frohman, 2006). The designs differ, and no study has measured it for the No DAC form in humans.

Are tesamorelin and CJC-1295 prohibited in sport?

Yes. The 2026 WADA Prohibited List names both as GHRH analogs under S2.2.4, in class S2, which is prohibited at all times.