CJC-1295

CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH), the brain signal that tells the pituitary gland to release growth hormone (GH). It is a 30-amino-acid, four-substitution derivative of GHRH's first 29 amino acids, with an engineered lysine at the tail that carries a reactive maleimide group ³. That tail is the core design trick: after subcutaneous injection it latches onto serum albumin, the most abundant protein in blood, forming a stable 'drug affinity complex' (DAC) that resists the enzymes which normally clear GHRH within minutes ³.

The result is a releasing peptide with a half-life of 5.8–8.1 days. A single dose raises GH 2- to 10-fold for six or more days, and insulin-like growth factor 1 (IGF-1) 1.5- to 3-fold for 9–11 days ¹. Because the signal is the body's own releasing hormone rather than injected GH, the natural pulse rhythm is largely preserved ².

Where it comes from

CJC-1295 emerged from a search for GHRH derivatives that could bioconjugate to albumin. Among three candidates, it was selected for stability against dipeptidyl peptidase-IV (DPP-IV), the enzyme that clips native GHRH apart, and for plasma persistence beyond 72 hours in rats ³. Two placebo-controlled Phase 1 trials in healthy adults followed in 2006 ¹. By 2009 authorities were already identifying the compound in a seized illicit preparation ¹³, and anti-doping laboratories built dedicated detection methods through 2010–2019 ⁵.

What it is studied for

The controlled human literature covers one thing thoroughly: pharmacokinetics and pharmacodynamics, meaning how long the drug lasts and which hormones it raises. It does not establish clinical benefit. Sports-medicine reviews confirm there are no human efficacy trials for muscle, recovery, or body-composition outcomes ⁸. One naming caution: 'CJC-1295 without DAC' is a different, short-acting product (Mod GRF 1-29) cleared in minutes and dosed several times daily; the trial data and most of this page describe the long-acting DAC form ⁷. CJC-1295 itself is not FDA-approved; the approved long-acting GHRH analog in the class is tesamorelin ⁹.

CJC-1295 amplifies the body's own growth hormone (GH) output rather than replacing it. GH release is normally driven by growth hormone-releasing hormone (GHRH), a short-lived signal that acts on growth-hormone-producing cells (somatotrophs) in the anterior pituitary. Native GHRH is destroyed within minutes by an enzyme called dipeptidyl peptidase-IV (DPP-IV), which clips a specific bond in its peptide chain ¹. CJC-1295 is built on the first 29 amino acids of GHRH with four substitutions that block that clip ¹.

The fifth modification is the defining one: a maleimide arm on a C-terminal lysine binds covalently to serum albumin within minutes of injection, forming the drug affinity complex that gives the long-acting form its 'DAC' name ³. A small peptide tethered to albumin inherits albumin's slow clearance, which is how the half-life stretches from minutes-scale GHRH to 5.8–8.1 days ¹. The albumin-bound peptide still activates the GHRH receptor on pituitary somatotrophs, triggering a chemical cascade inside those cells that increases GH production and pushes stored GH into the bloodstream ¹. The resulting GH tells the liver to make insulin-like growth factor 1 (IGF-1), and most downstream anabolic and tissue-repair signaling is attributed to IGF-1 pathways ¹.

A key finding from the human trials is what does not happen: continuous receptor stimulation does not flatten the natural rhythm. One week after a single 60 or 90 µg/kg dose, GH pulse frequency and size were unchanged, while the baseline between pulses rose 7.5-fold and IGF-1 was up 45% ². In other words, the compound deepens the valley between pulses rather than sharpening the peaks.

Secondary and longer-term actions

• Somatotroph support: in mice born without GHRH, daily CJC-1295 restored pituitary GH production and normalized growth, consistent with a trophic effect on the GH-producing cell pool ⁴. A separate mouse model tied this pathway to M3 muscarinic receptor signaling in the brain-pituitary axis ¹⁵.
• IGF-1-mediated tissue effects: musculoskeletal outcomes attributed to GH secretagogues are thought to act through IGF-1, including satellite cell activation and muscle repair, rather than through the peptide directly ¹⁶.
• Serum protein shifts: one dose changed measurable serum proteins in healthy men: apolipoprotein A1 and transthyretin isoforms decreased, while beta-hemoglobin and albumin fragments increased, with one fragment tracking IGF-1 levels linearly ¹¹.
• Endocrine risk pathways: sustained GH/IGF-1 elevation carries class-level effects: fluid retention, dysglycemia, and a biologically plausible but unproven mitogenic concern from chronically high IGF-1 ⁷.

How long it lasts

Parameter	Finding
Half-life	5.8–8.1 days 1
GH response	2- to 10-fold above baseline for 6+ days after one dose 1
IGF-1 elevation	1.5- to 3-fold for 9–11 days 1
Baseline GH at 1 week	+7.5-fold, pulses preserved 2
Cumulation	IGF-1 above baseline 28 days after repeat dosing 1

The dose-response curve appears to plateau around 60 µg/kg: 90 µg/kg produced no meaningful extra GH or IGF-1 response ².

CJC-1295's documented effects split into two groups: hormone-level changes that are well measured in controlled human studies, and downstream outcomes (body composition, recovery, performance) that remain unproven.

What is established

• Prolonged GH elevation: single subcutaneous doses raise GH 2- to 10-fold for at least six days, with IGF-1 up 1.5- to 3-fold for 9–11 days ¹.
• Preserved pulsatility: one week after a 60–90 µg/kg dose, baseline GH between pulses was 7.5-fold higher, mean GH was up 46%, and IGF-1 was up 45%, while the pulse rhythm stayed intact ².
• Cumulative rise with repeat dosing: weekly or biweekly dosing kept IGF-1 above baseline for up to 28 days after the last administration ¹.
• Growth normalization in animals: in mice born without GHRH, daily dosing for five weeks normalized body weight, length, lean mass, and subcutaneous fat; dosing every 48–72 hours was inferior ⁴.
• Muscle function in a mouse wasting model: CJC-1295 combined with ipamorelin improved maximum tetanic muscle tension in glucocorticoid-induced muscle loss ⁹.

What is not established

• No human efficacy trial tests CJC-1295 for muscle gain, fat loss, injury recovery, skin, or sleep; sports-medicine reviews state this gap directly ⁸.
• Serum protein shifts after a single dose (lower apolipoprotein A1 and transthyretin isoforms, higher albumin and hemoglobin fragments) are measurable but clinically unexplained ¹¹.
• Community-reported benefits, including lean mass, fat loss, sleep quality, and skin, rest on anecdotes and forum reports, such as a 2016 netnography of female users ¹².

Claim	Evidence	Strength
Sustained GH and IGF-1 elevation	Human RCT (PK/PD)	High 1
Growth restoration in GHRH deficiency	Mouse model	Preclinical 4
Injury or recovery benefit	None in humans	Very low 8
Fat loss, skin, and sleep claims	Community reports	Anecdotal 12

In plain terms: the hormone effect is real and reproducibly measured; the clinical benefits people attribute to it have not been confirmed in controlled research.

Every controlled human study of CJC-1295 used subcutaneous injection; no other route has published pharmacokinetic, efficacy, or tolerability data ¹. Single doses in the Phase 1/2 trials ranged from 30 to 90 µg/kg, and the best-tolerated window was 30–60 µg/kg, which for a 72.7 kg (160 lb) adult equals about 2.2–4.4 mg per injection ¹. Repeat-dose arms used weekly or biweekly injection for 28–49 days and showed a cumulative IGF-1 effect ¹.

One nuance matters for every dose discussion: 60 and 90 µg/kg produced statistically indistinguishable GH and IGF-1 responses, suggesting the response plateaus near 60 µg/kg ².

Commonly used protocols

Because two products share the CJC-1295 name, two community schedules exist in parallel (community protocol):

• CJC-1295 with DAC (long-acting): 2–3 mg subcutaneously once weekly, sometimes 1–2 mg twice weekly, typically 8–12 weeks on followed by 4–8 weeks off ⁷. For a 72 kg adult the weekly total lands around 28–41 µg/kg, near or below the trial doses ¹.
• CJC-1295 without DAC (Mod GRF 1-29): 100–300 µg per injection one to three times daily, fasted, often for 12–16 weeks, frequently with a secretagogue such as ipamorelin added to sharpen each pulse (community protocol) ⁷.

Animal data support regular spacing: daily dosing normalized growth in GHRH-deficient mice, while 48- to 72-hour spacing was only partially effective ⁴. That supports once-weekly spacing for the long-acting form rather than month-scale gaps.

Timing

For the DAC form, injection timing within the day matters little, because the albumin-bound reservoir supplies continuous receptor drive ¹. For the short-acting no-DAC form, timing matters more: protocols use fasted injections, typically 30–60 minutes before meals or at bedtime, since insulin and glucose after meals blunt GH output (community protocol). Bedtime dosing overlaps the body's largest natural GH pulse.

Onset, peak, and washout

• Onset: a single dose raises GH for six or more days and IGF-1 for 9–11 days ¹. Forum users report better sleep, energy, and skin within the first week, though this evidence is weak ¹².
• Peak: repeat dosing accumulates; IGF-1 stayed above baseline for up to 28 days after a course ¹.
• After stopping: with a 5.8–8.1 day half-life, near-complete washout takes roughly 30–40 days ¹. No rebound or withdrawal is documented in the human trials, but the longest controlled exposure was only 49 days ¹.

CJC-1295 is supplied as a lyophilized (freeze-dried) powder that must be dissolved before use. The standard diluent in research and community protocols is bacteriostatic water, which contains a small amount of benzyl alcohol to prevent bacterial growth; sterile saline is an acceptable alternative (community protocol). The interactive calculator below converts vial size and diluent volume into exact draw volumes.

To mix, drip the diluent slowly down the inside wall of the vial and swirl gently until the solution clears; shaking can damage the peptide (community protocol). The maleimide arm on the DAC form is moisture- and thiol-reactive, so the powder should stay sealed and dry until use, and thiol-containing diluents or reducing agents should be avoided ³. The no-DAC form dissolves the same way but lacks the reactive maleimide, so that particular concern does not apply ⁷.

Storage

• Lyophilized powder: store at about -20°C for the long term; refrigeration at 2–8°C is acceptable for shorter periods. Keep it dry and protected from light (community protocol).
• Reconstituted solution: refrigerate at 2–8°C. In-vitro stability data indicate GHRH analogs degrade in solution above 4°C ²¹. Community guidance is to discard reconstituted vials after roughly 14–30 days, and to avoid repeated freeze-thaw cycles of the solution (community protocol).

Product quality

The dominant practical risk is the product itself. Independent testing of consumer-marketed research peptides, including CJC-1295, found that 41.6–71.1% of 6,441 samples failed basic purity or abundance criteria, and 15% contained measurable endotoxin ¹⁰. Third-party HPLC and endotoxin testing are standard before first use (practitioner consensus). Filtering through a 0.22 µm filter removes bacteria but not endotoxin, so filtration cannot rescue a contaminated vial.

No formal drug-drug interaction trials exist for CJC-1295. The guidance below is derived from its mechanism, a week-long albumin-bound residence ¹, and the class-wide side effect profile of growth-hormone-axis peptides ⁷.

Medications expected to interact

• Insulin and sulfonylureas (moderate): sustained GH opposes insulin action, and dysglycemia is a documented class effect of GH-axis peptides ⁷. Elevated IGF-1 is itself insulin-sensitizing, so net glycemic effects are unpredictable; fasting glucose monitoring is the standard approach (practitioner consensus).
• Exogenous growth hormone (contraindicated): redundant pharmacology with additive IGF-1, fluid retention, and acromegalic-type effects (theoretical) ⁷.
• IGF-1 products such as mecasermin, IGF-1 LR3, or PEG-MGF (avoid): additive IGF-1 signaling compounds hypoglycemia risk and mitogenic concern (theoretical) ⁷.
• Glucocorticoids (moderate): steroids suppress the growth axis and cause muscle wasting; in mice, CJC-1295 plus ipamorelin improved muscle tension in a glucocorticoid-induced wasting model ⁹. Combined use adds hyperglycemic burden.
• Oral estrogens (moderate): oral estrogen blunts liver IGF-1 output, so the IGF-1 response may be attenuated; female users report difficulty estimating dose and cycle length for this reason ¹².
• Androgens (moderate): additive IGF-1, fluid retention, and dyslipidemia; growth-axis polypharmacy is associated with cardiovascular strain and psychiatric instability in multi-drug users ¹⁴.
• Levothyroxine (monitor): GH increases T4-to-T3 conversion and may unmask central hypothyroidism; thyroid function is rechecked after 4–6 weeks (practitioner consensus).
• Somatostatin analogues such as octreotide (antagonistic): they suppress pituitary GH release directly, opposing GHRH-receptor stimulation ⁷.
• Dopamine agonists such as cabergoline (mildly antagonistic): dopaminergic tone suppresses GH, so a blunted response is expected (practitioner consensus).
• DPP-IV inhibitors such as sitagliptin (no interaction expected): CJC-1295 is engineered to resist DPP-IV cleavage, so enzyme inhibition should not change its exposure ³.

Supplements

No supplement interaction studies exist; the following reflects community protocol and practitioner consensus.

Supplement	Why it comes up
Arginine, ornithine, glycine, glutamine blends	Additive GH release; watch for post-dose hypoglycemia (community protocol)
Alpha-GPC	Choline precursor; cholinergic tone facilitates GH release, with animal support for that pathway 15
Melatonin	Overlaps the natural nocturnal GH pulse; mild additive effect (community protocol)
Berberine, alpha-lipoic acid	Insulin sensitizers used to counter GH-driven insulin resistance (community protocol)
Alcohol	Blunts stimulated GH secretion; avoided on dosing days (practitioner consensus)

Conditions that change the calculus

Practitioner guidance treats active or recent cancer, diabetes or impaired glucose tolerance, cardiovascular disease, acromegaly or pituitary adenoma, untreated hypothyroidism or adrenal insufficiency, and pregnancy as reasons to avoid CJC-1295, grounded in IGF-1 growth signaling and the documented class effects ⁷. Elite athletes fall under WADA jurisdiction, where the compound is prohibited at all times ¹³.

Whether the body desensitizes to CJC-1295 over time is unresolved. The human trials are too short to answer it: the longest controlled exposure was 49 days ¹. What the trials do show is that the axis keeps responding, with a cumulative IGF-1 effect across repeat doses rather than a fading one ¹. Pituitary downregulation is not documented in humans, but no study has looked over the months that current research cycles span (community protocol).

In practice, community protocols treat CJC-1295 as a cycled compound (community protocol):

Protocol	On-cycle	Off-cycle
CJC-1295 with DAC	8–12 weeks, 2–3 mg once weekly	4+ weeks 7
CJC-1295 without DAC (Mod GRF 1-29)	12–16 weeks, 100 µg 1–3× daily	4+ weeks 7

Some schedules split the DAC dose to 500 µg every other day to smooth peak-related symptoms, and a minority run 5-days-on, 2-days-off micro-cycles (community protocol).

Why off-periods exist

Practitioner reasoning is practical (practitioner consensus): IGF-1 takes weeks to return to baseline after the last dose, since effects persist up to 28 days ¹; off-periods limit drift in prolactin and cortisol and the dysglycemia risk ⁷; and chronic GH/IGF-1 activation carries a biologically plausible but unproven mitogenic concern that argues against continuous exposure ⁷. Cost matters too.

Signals to pause

• IGF-1 no longer rises on the same dose; sleep and recovery benefits plateau (community protocol).
• Prolactin or cortisol drift, appetite changes, or dysglycemia ⁷.
• Fluid retention, joint or muscle aches, or persistent injection-site reactions ⁷.
• In women, persistent water retention or menstrual irregularity, as reported in forum data ¹².

After stopping, washout follows the half-life, about 30–40 days to near-complete clearance ¹. No rebound or withdrawal syndrome is documented, and resuming after a break typically means picking up the previous dose rather than a loading dose (community protocol).

CJC-1295 is rarely used alone in community practice; the most common partner is a growth hormone secretagogue such as ipamorelin ⁷.

Peptide combinations that come up

• CJC-1295 + ipamorelin (most common): CJC-1295 acts through the GHRH receptor, while ipamorelin acts through the ghrelin receptor (GHS-R1a), so the pair combines an elevated baseline with sharper pulses ⁷. Ipamorelin is favored for being more receptor-selective, with less prolactin and cortisol drift than older secretagogues, though prolactin and cortisol elevation is a class concern either way ⁷. In mice with glucocorticoid-induced muscle loss, the combination improved maximum muscle tension ⁹. When the short-acting no-DAC form is used, ipamorelin 200–300 µg is often stacked to add pulse amplitude on top of each injection (community protocol).
• CJC-1295 + GHRP-2, GHRP-6, or hexarelin: functionally redundant with ipamorelin and carries a higher reported prolactin and cortisol burden ⁷.
• CJC-1295 + tesamorelin or sermorelin: all three target the GHRH receptor, so combining them is redundant ⁷.
• CJC-1295 + MK-677: both drive the same GH/IGF-1 axis; the combination adds dysglycemia and fluid-retention risk, and MK-677 carries its own cautions for insulin resistance and cardiovascular effects ¹⁴.
• CJC-1295 + semaglutide or tirzepatide: a popular pairing, because GLP-1 receptor agonists blunt the glucose elevation that GH can cause. The combination itself is essentially unstudied, though the GLP-1 class holds the strongest human evidence base among peptide drugs for metabolic benefit ⁷.
• CJC-1295 + IGF-1 LR3 or PEG-MGF: additive IGF-1 signaling raises hypoglycemia and mitogenic concerns; avoided in practitioner guidance (theoretical) ⁷.
• CJC-1295 + BPC-157, TB-500, or GHK-Cu: no shared receptors; repair peptides and growth-axis peptides are commonly combined in injury-recovery protocols with no known interaction (practitioner consensus).
• CJC-1295 + AOD-9604: AOD-9604 is a GH fragment oriented toward lipolysis; the hoped-for additive fat-loss synergy is unproven (practitioner consensus).

One quality caveat applies to every stack: consumer peptide samples fail basic purity checks at high rates, and mislabeling means the actual contents of any single vial are uncertain until independently tested ¹⁰.

CJC-1295 is not approved by the FDA for any indication, and no marketing authorization is documented in any major jurisdiction ¹⁴. Clinical development stalled after the Phase 1/2 pharmacokinetic and pharmacodynamic studies: the 2006 trials measured GH and IGF-1 responses in healthy adults and showed tolerability at 30–60 µg/kg, but no pivotal trial, approval, or licensing followed ¹.

Instead, the compound circulates through gray-market channels sold as a 'research compound,' a labeling category that carries no requirement to prove safety or efficacy ¹⁸. Independent quality data explain why that matters: across 6,441 consumer-marketed peptide samples, 41.6–71.1% failed basic quality criteria and 15% showed endotoxin contamination ¹⁰. Norwegian authorities identified CJC-1295 in a seized pharmaceutical preparation as far back as 2009 ¹³, and forum intelligence has cataloged hundreds of doping suppliers offering it ²². No controlled-substance scheduling appears in the reviewed literature; legal exposure instead runs through unapproved-drug and misbranding rules plus state pharmacy law (practitioner consensus).

Sport and anti-doping

CJC-1295 is prohibited at all times, in and out of competition, under Section S2 of the World Anti-Doping Agency (WADA) Prohibited List, the class covering peptide hormones, growth factors, and their mimetics ¹³. WADA-accredited laboratories operate validated urine methods with detection limits around 0.5–1 ng/mL ¹⁹, and the albumin conjugation does not hide it: specialized immuno-PCR and immunoaffinity workflows specifically target the conjugate ⁶. Horse racing regulates the compound separately, with plasma detection confirmed below 50 pg/mL ⁵.

One gap is worth noting: as of 2021, no WADA-accredited laboratory had reported a confirmed CJC-1295 finding in an athlete sample, even though admissions and intelligence indicate real-world use. Low urinary concentrations and incomplete knowledge of its metabolism are the cited reasons ²¹.

In plain terms: CJC-1295 is an unapproved injectable everywhere its status has been reviewed, and importation for personal use conflicts with medical-products law in most jurisdictions ¹⁸.

In the only placebo-controlled human trials, healthy adults receiving single or repeat subcutaneous doses for up to 49 days reported no serious adverse reactions, and the compound was best tolerated at 30–60 µg/kg ¹. That short window is the entire controlled human safety record; everything beyond it is extrapolation from the broader growth-hormone-axis peptide class ⁷.

Class-wide side effects

Because CJC-1295 raises GH and IGF-1 for days, the expected pharmacodynamic effects are often experienced as symptoms. Water retention and joint stiffness track the 7.5-fold rise in baseline GH and 45% IGF-1 rise seen after a single dose ². Across GH-axis peptides in clinical use, the documented adverse events are ⁷:

• Injection-site reactions
• Fluid retention (edema)
• Muscle and joint aches (myalgia and arthralgia)
• Prolactin and cortisol elevations
• Appetite changes
• Dysglycemia (blood glucose changes)

Flushing, transient headache, and noticeably better sleep are also common user reports; improved sleep is one of the explicitly stated reasons for use in bodybuilding forums ¹².

Metabolic and cardiovascular cautions

Signals beyond the 49-day window come from the secretagogue class rather than CJC-1295 itself. Insulin resistance, dyslipidemia, and cardiovascular strain are documented risks of sustained GH elevation ¹⁴. The related oral secretagogue MK-677 has been associated with congestive heart failure in a sports-medicine review ¹⁴; no CJC-1295-specific case is published, but the class caution carries over. Anxiety and mood changes are reported across GH secretagogues as well ¹⁴.

Theoretical and rare concerns

• Pituitary cell growth: chronic GHRH-receptor stimulation expanded the GH-producing cell pool in mice ⁴. Pituitary hyperplasia from human use is unproven but plausible.
• Mitogenic concern: chronically elevated IGF-1 growth signaling is a standard class caution ⁷.
• Immunogenicity: antibodies against the albumin-conjugated peptide could blunt efficacy or trigger hypersensitivity over long cycles (theoretical).
• Irreversibility: because the peptide binds covalently to albumin, a dosing error or accidental overdose sustains supraphysiological GH/IGF-1 for weeks and cannot be reversed quickly ¹.
• Acromegalic features: with sustained supraphysiologic IGF-1, acromegalic-type changes such as frontal bossing, acral growth, and carpal tunnel are theoretically possible.

Who should avoid it

Practitioner guidance places active or recent cancer, acromegaly or pituitary adenoma, diabetes or insulin resistance, established cardiovascular disease, and pregnancy or breastfeeding in the avoid or extreme-caution column, grounded in IGF-1 growth signaling and the class side-effect profile ⁷. Competing athletes under WADA jurisdiction face a categorical prohibition ¹³.

The product itself is a risk factor

A major confounder sits upstream of the peptide: in a 6,441-sample analysis of consumer-market peptides, 41.6–71.1% failed basic purity or abundance standards and 15% carried endotoxin ¹⁰. Flu-like symptoms or injection reactions after a new vial may reflect contaminants rather than CJC-1295.

What monitoring looks like

Typical research monitoring panels track IGF-1 as the response marker, fasting glucose and HbA1c for dysglycemia, lipids, prolactin and cortisol, and a chemistry panel for fluid balance, drawn at baseline, around week four, at the end of a cycle, and a few weeks after stopping ¹. A meaningful IGF-1 rise by week four supports both product authenticity and axis response (practitioner consensus).