TL;DR
CJC-1295 + Ipamorelin. A 3–5× GH pulse. The stack the whole peptide clinic market prescribes.
What is it? CJC-1295 (no DAC, the modified GRF 1-29 form) plus Ipamorelin. Subq, bedtime, fasted. 8–12 week cycles. Aims to amplify endogenous GH rather than administer exogenous hGH.
What does it do? Two inputs on the same pituitary somatotroph: CJC-1295 hits GHRH receptors, Ipamorelin hits ghrelin receptors (GHSR-1a). Dual agonism yields a GH pulse 3–5× larger than either alone. Hepatic IGF-1 rises 12–24 hours later.
Does the evidence hold up? No stack-specific RCT. Individual Phase 2 data: Teichman 2006 (CJC-1295 DAC, not the no-DAC form), Raun 1998 (Ipamorelin selectivity), Gobburu 1999 (Ipamorelin PK/PD). The dual-input pituitary physiology is standard endocrinology.
Who uses it? Adults 35+ in the compounding and research-peptide world targeting body composition, sleep, and recovery. Typically 8–12 week cycles.
Bottom line? Real pituitary physiology backs the combo. The stack itself has no RCT.
What It Is
The GH Stack is a community term for the combination of CJC-1295 (no DAC, the short-acting Modified GRF 1-29 form) with Ipamorelin, administered together subcutaneously at bedtime on an empty stomach. The protocol has been the dominant community approach to pituitary-mediated growth-hormone amplification since approximately 2010, when both compounds reached the North American research-peptide market in reliable form. Its theoretical basis is standard anterior-pituitary endocrinology: GH release from somatotroph cells requires two independent ligand signals — GHRH at GHRH receptors and a ghrelin-receptor agonist at GHSR-1a — to produce a maximal GH pulse. Administering a GHRH analog and a ghrelin-receptor agonist together provides both inputs simultaneously.
CJC-1295 (no DAC) — also sold as Modified GRF 1-29 — is a 29-amino-acid GHRH(1-29) analog with four substitutions (D-Ala², Gln⁸, Ala¹⁵, Leu²⁷) conferring resistance to DPP-IV cleavage. Half-life is approximately 30 minutes — long enough to produce a substantial GH pulse, short enough to preserve the pulsatile architecture of endogenous GH secretion. "No DAC" distinguishes it from the DAC-conjugated version (CJC-1295 with DAC), which has a multi-day half-life and produces sustained GH elevation rather than pulses. For the GH Stack, the no-DAC form is strongly preferred — the goal is pulse amplification, not flat chronic GH elevation.
Ipamorelin is a selective pentapeptide growth-hormone secretagogue that agonizes the growth hormone secretagogue receptor 1a (GHSR-1a, the ghrelin receptor) with minimal effects on cortisol and prolactin at therapeutic doses. This selectivity distinguishes it from earlier GHRPs (GHRP-6, GHRP-2, hexarelin), which elevate cortisol and/or prolactin alongside their GH effect. Half-life is approximately 2 hours. For chronic or repeated-cycle use, Ipamorelin is the cleanest GHRP because of its receptor selectivity.
The combination is sold in the research-peptide market either as two separate vials (the community standard, because the 100 mcg CJC + 200–300 mcg Ipamorelin asymmetric ratio does not match 1:1 pre-blends well) or as a 1:1 pre-blend (typically 5 mg / 5 mg), which forces symmetric dosing. Neither component is FDA-approved. Both were on the FDA Category 2 Bulk Drug Substances list as of early 2025; the HHS Secretary Robert F. Kennedy Jr. announcement in February 2026 signaled intent to reclassify approximately 14 of 19 Category 2 peptides back to Category 1, but formal FDA implementation has not been issued as of April 2026. Both are WADA-banned (S2 — peptide hormones, growth factors, related substances and mimetics).
Mechanism of Action
- Dual-receptor synergy — CJC-1295 binds GHRH receptors (class-B GPCR, Gαs-coupled, adenylate cyclase / cAMP / PKA cascade). Ipamorelin binds GHSR-1a (class-A GPCR, Gαq-coupled, phospholipase C / IP3 / Ca²⁺ cascade). Different G-protein pathways converging on the same somatotroph GH-releasing machinery. The pulse produced by both ligands together is substantially larger than either alone.
- Pulse preservation — Short-half-life pair (CJC no-DAC ~30 min; Ipamorelin ~2 h) produces a GH pulse that rises and clears, mimicking physiologic secretion. DAC-modified CJC or recombinant hGH produce flat elevated GH that downregulates endogenous regulatory feedback.
- Ipamorelin selectivity — Minimal cortisol and prolactin elevation distinguishes Ipamorelin from GHRP-6 and hexarelin. This is the principal reason Ipamorelin is the long-term-use choice in this stack (Raun 1998, Eur J Endocrinol; PMID 9849822).
- Somatostatin timing — Endogenous somatostatin (the GH brake) drops during slow-wave sleep and after fasting. Bedtime fasted dosing aligns the stack with natural physiologic windows where somatostatin is already low, maximizing pulse size.
- Downstream IGF-1 — The GH pulse drives hepatic IGF-1 synthesis with a ~12–24 h delay. IGF-1 is the effector for most of the body-composition and recovery outcomes (lean mass gain, modest fat loss, improved recovery from training).
- Sleep architecture — Endogenous GH pulses cluster during slow-wave sleep. The stack may deepen slow-wave sleep in responders. Subjective "best sleep in years" reports are common and consistent with the mechanism.
- Not tachyphylactic at typical doses — Both components at standard community doses do not produce rapid receptor desensitization over an 8–12 week cycle. The 5-on/2-off weekly pattern and inter-cycle washouts provide additional insurance against receptor downregulation.
- What it does not do — Does not directly supply exogenous GH; pituitary function must be reasonably intact. Users with pituitary insufficiency (prior surgery, empty sella, hypophysitis) are non-responders. Does not engage androgen, insulin, or other anabolic axes directly.
What the Research Shows
There is no stack-level RCT of CJC-1295 (no DAC) + Ipamorelin in combination. The published evidence is at the component level.
- CJC-1295 (DAC version) Phase 2 pharmacodynamics — Teichman et al. 2006 (J Clin Endocrinol Metab; PMID 16352683) — the DAC-modified version of CJC-1295 produced sustained elevation of GH and IGF-1 in healthy adults. Note: this is the DAC form, not the no-DAC form used in the GH Stack; the translation to the no-DAC version is inferential.
- CJC-1295 pulse preservation — Ionescu & Frohman 2006 (J Clin Endocrinol Metab; PMID 16982668) — pulsatile GH secretion persists during continuous stimulation by CJC-1295. Supports the mechanistic claim that GHRH analogs amplify rather than flatten the GH pulse architecture.
- Ipamorelin discovery and selectivity (Raun 1998) — Eur J Endocrinol (PMID 9849822). First characterization of Ipamorelin as a selective GHSR-1a agonist with minimal cortisol and prolactin elevation. The foundational paper for Ipamorelin's place in this stack.
- Ipamorelin human PK/PD (Gobburu 1999) — Pharm Res (PMID 10496657). Pharmacokinetic-pharmacodynamic modeling in human volunteers. Established dose-response for GH release and the ~2-hour half-life.
- CJC-1295 normalization in GHRH-knockout mouse (Alba 2006) — Am J Physiol Endocrinol Metab (PMID 16895898). Demonstrated that CJC-1295 can restore normal growth in GHRH-deficient animals.
- Sermorelin and related GHRH analogs (Walker 2006) — Clin Interv Aging (PMID 18046908). Context for the broader GHRH-analog approach to adult GH insufficiency.
- Pulsatile GHRP-2 infusion (Bowers 2004) — J Clin Endocrinol Metab (PMID 15126555). Sustained elevation of pulsatile GH and IGF-1 secretion in older adults with a different GHRP. Provides class context.
- MK-677 (oral GH secretagogue, related class) — Svensson et al. 1998 (J Clin Endocrinol Metab; PMID 9467542). Two-month MK-677 increased GH, IGF-1, fat-free mass, and energy expenditure in obese subjects. A class-relevant longer-duration study.
- Ghrelin-system integration (Veldhuis & Bowers 2010) — Int J Pept (PMID 20798846). Synthesis of the ghrelin/GHSR system's role in GH regulation.
- Body-composition context in hypogonadal men (Sinha 2020) — Transl Androl Urol (PMID 32257854). GH secretagogues in the context of modern body-composition optimization in hypogonadal males.
- No published stack RCT — There is no randomized controlled trial of the specific CJC-1295 (no DAC) + Ipamorelin combination at community-standard doses in healthy adults.
Evidence Summary
The individual components have solid Phase 1/2 evidence. The synergy claim is well-supported by pituitary endocrinology but not by a dedicated combination-RCT. The community-standard doses (100 mcg CJC + 200–300 mcg Ipamorelin) sit within the dose ranges used in individual-compound trials. The bedtime-fasted protocol reflects the pituitary-somatostatin biology. The effect size is real and typically smaller than what users expect from recombinant hGH — that gap is intentional and preserves endogenous physiologic feedback.
Human Data
- Teichman 2006 (CJC-1295 DAC) — healthy adults — DAC-modified CJC-1295 SubQ in healthy adults. Sustained GH and IGF-1 elevation. Not the no-DAC form, but foundational pharmacology for the molecule.
- Ionescu 2006 (CJC-1295, pulsatility) — Pulsatile GH secretion preserved during CJC-1295 stimulation.
- Gobburu 1999 (Ipamorelin PK/PD) — Human healthy-volunteer PK modeling. Dose-response for GH release. Established the ~2 h half-life.
- No combination stack RCT — No human RCT of CJC (no DAC) + Ipamorelin specifically.
- Community real-world experience (uncontrolled) — Large but uncontrolled community data. IGF-1 elevation on bloodwork is the most consistent objective signal in compliant users; subjective sleep and body-composition improvements are commonly reported but heavily placebo-confounded.
- Non-responder pattern — If 4-week IGF-1 does not rise from baseline, investigate (in order): product quality, injection technique (intramuscular rather than SubQ blunts absorption), recent meal before dose, pituitary dysfunction (uncommon but real).
Dosing from the Literature
Dosing below reflects the community-standard protocol derived from component-level pharmacokinetics and pituitary-stimulation physiology. No FDA-approved dose exists for either component.
| Protocol | CJC-1295 (no DAC) | Ipamorelin | Notes |
|---|
| Standard bedtime (most common) | 100 mcg | 200 mcg | 5 days on / 2 off weekly, 8–12 weeks cycle. Bedtime fasted. |
| Higher-dose bedtime | 100 mcg | 300 mcg | For body-composition focus; more pronounced hunger and sleep effects. |
| 2× daily (AM fasted + PM) | 100 mcg per injection | 200 mcg per injection | Morning pre-training + bedtime. Requires fasted windows around both. |
| 3× daily (intensive) | 100 mcg per injection | 200 mcg per injection | AM / post-workout / bedtime. Diminishing returns per additional dose. |
| Symmetric 1:1 pre-blend | 100–300 mcg | 100–300 mcg | Forced symmetric ratio; less common community choice. |
| Cycle length | — | — | 8–12 weeks on, 4–8 weeks off. Desensitization reported beyond ~16 weeks continuous. |
Dosing Disclaimer
Bedtime fasted dosing (within 30–60 minutes of bed, at least 2 hours after the last meal) is non-negotiable for the GH stack. Insulin from a recent meal blunts the GH pulse; simple carbohydrates immediately before dosing substantially reduce pulse size. Combining both compounds in one U-100 insulin syringe is common community practice (4 units CJC + 8 units Ipamorelin at 2.5 mg/mL reconstitution = 100 mcg / 200 mcg). Always run one component at a time initially to establish tolerance before combining. Cancer screening should be current before initiation given IGF-1 mitogenicity.
Reconstitution & Storage
The GH stack is usually run as two separate vials. The standard community ratio (100 mcg CJC + 200–300 mcg Ipamorelin) does not fit a 1:1 pre-blend; some 5 mg / 5 mg pre-blends exist but force symmetric dosing.
| Format | Reconstitution | Concentration | Typical Dose Draw |
|---|
| CJC-1295 (no DAC) 5 mg standalone | 2 mL BAC water | 2.5 mg/mL (25 mcg per unit) | 100 mcg = 4 units (0.04 mL) |
| Ipamorelin 5 mg standalone | 2 mL BAC water | 2.5 mg/mL (25 mcg per unit) | 200 mcg = 8 units; 300 mcg = 12 units |
| Pre-blend 5 mg / 5 mg (1:1) | 2 mL BAC water | 2.5 mg/mL each (5 mg/mL total) | 4 units = 100/100; 8 units = 200/200 |
| Combined-syringe bedtime injection | Draw from both vials | — | 4 units CJC + 8 units Ipa = 100/200 (total 12 units) |
- Reconstitution technique — Inject BAC water slowly down the vial wall at 45°; swirl gently, never shake. Clear, colorless solution both vials.
- Storage (unreconstituted) — 2–8°C preferred; lyophilized peptides stable for 24+ months.
- Storage (reconstituted) — 2–8°C refrigerated; use within 21–28 days for both peptides.
- Injection sites (SubQ) — Abdomen (2 inches from navel), thigh, or upper arm. Rotate sites during the cycle.
- Timing — Bedtime (within 30–60 min of sleep) is the anchor for the single-daily protocol. Fasted ≥2 hours since the last meal.
- Inspection — Clear colorless solution. Discard if cloudy, discolored, or past BUD.
→ Use the Kalios Peptide Calculator for exact syringe units
Side Effects & Risks
Important
Neither component is FDA-approved, and both are WADA-banned (S2). Athletes on competitive testing should not use. Ask your provider about risks before starting a cycle.
- Injection site reactions — Mild erythema or induration; usually resolve within 24 hours. Rotate sites.
- Hunger (Ipamorelin) — Real ghrelin-receptor effect. Most intense in the first 30 minutes post-injection. Bedtime dosing minimizes daytime impact; some users find managing this difficult.
- Water retention — Particularly facial (puffy morning face) in weeks 1–3. Real GH effect; resolves as IGF-1 normalizes the balance, usually by week 4. Reduce dose if persistent.
- Mild carpal tunnel symptoms — Tingling / numbness in hands or feet from GH-induced fluid accumulation. Uncommon at 100/200 dosing; more common at 300/300 or above. Reduce dose.
- Transient insulin resistance — GH is mildly counter-regulatory to insulin. Small fasting glucose elevation (5–15 mg/dL) is common and clinically insignificant in healthy users. Relevant in diabetic or prediabetic users — monitor HbA1c.
- Vivid dreams, sleep changes — Usually welcomed. Some users report disrupted sleep rather than deeper sleep; dose earlier in the evening or reduce dose if this happens.
- Joint aches — Uncommon at this dose range; more common at recombinant hGH doses.
- IGF-1 elevation (intended) — The expected effect. Uncapped chronic IGF-1 elevation has theoretical cancer-promotion concerns. Target IGF-1 should stay within age-appropriate normal range, not supraphysiologic.
- Cancer concern — IGF-1 is mitogenic. Active or recent malignancy is a contraindication. Age-appropriate cancer screening should be current before starting.
- Thyroid — Ipamorelin does not meaningfully affect thyroid function at therapeutic doses, but baseline TSH and free T4 are reasonable pre-cycle labs.
- Mild cortisol elevation (Ipamorelin) — Generally minimal at therapeutic doses; clinically meaningful elevations reported only at supra-therapeutic doses.
- Pregnancy and lactation — Contraindicated.
- Pediatric use — Not appropriate outside clinical-trial settings.
- WADA prohibited — Both components banned at all times under S2. Any tested athlete faces sanction.
- Sourcing risk — Research-chemical market variability. Independent COA matters, especially for Ipamorelin given product-quality variance. CJC-1295 no-DAC can be mislabeled as DAC-modified; confirm with vendor and/or COA.
- Long-term safety — Data extend only to ~12 months of pulsatile use. Year-round continuous use is not supported and will desensitize the axis.
Bloodwork & Monitoring
- Age-appropriate cancer screening (pre-initiation) — Colonoscopy, mammography, PSA, derm per age. The single most important pre-cycle step given IGF-1 mitogenicity.
- IGF-1 — Baseline, 4 weeks (pulse saturation), cycle end (peak response), and 4 weeks post-washout (confirm baseline recovery). The cleanest objective readout of stack efficacy.
- Fasting glucose and HbA1c — Baseline and 6–8 weeks. Relevant for diabetic / prediabetic users.
- Fasting insulin — Baseline; informative for insulin-sensitivity tracking during cycle.
- Basic lipid panel — Standard cardiometabolic tracking.
- Prolactin and cortisol — Baseline confirmation that Ipamorelin is not elevating these (it generally should not at therapeutic doses).
- TSH and free T4 — Baseline; thyroid function is not a prominent GH-axis concern but basic thyroid assessment is prudent.
- CBC and CMP — Baseline and periodic.
- Body composition (DXA) — Objective lean-mass and fat-mass tracking; optional but informative.
- Ophthalmologic / diabetic retinopathy screening — Relevant in diabetic users; rapid glycemic or IGF-1 changes can affect retinopathy.
Commonly Stacked With
The GHRH component of the stack. See the full profile for molecule structure, PK, and the DAC-vs-no-DAC distinction.
The ghrelin-receptor component. See the full profile for selectivity data, PK, and cycle-usability discussion.
Stabilized GRF(1-44). Stronger GHRH signal; FDA-approved for HIV-associated lipodystrophy. Used as a drop-in replacement for CJC-1295 when visceral fat reduction is the specific goal.
GRF(1-29) without the four CJC-1295 modifications. Shorter half-life, slightly weaker. Sometimes favored by prescribing clinicians due to its longer compounding-pharmacy track record in the US.
Oral GH secretagogue, long-acting. Stacks with or substitutes for Ipamorelin. Different tolerability profile (hunger and water retention worse; easier oral dosing).
Sleep hygiene, protein, resistance training
The non-pharmacologic levers. Consistent bedtime, 1.6–2.2 g/kg protein, heavy lifting 3–4× per week amplify any GH-axis intervention dramatically. These foundations matter more than the peptide layer.
→ Check compound compatibility in the Stack Builder
Regulatory Status
Current Status — April 2026
The GH Stack combines two research peptides: CJC-1295 (no DAC) and Ipamorelin. Neither is FDA-approved for any indication. Both have been classified by the FDA as Category 2 Bulk Drug Substances, ineligible for 503A/503B compounding under current rules. HHS Secretary Robert F. Kennedy Jr.'s February 2026 announcement indicated intent to reclassify approximately 14 of 19 Category 2 peptides back to Category 1; as of April 2026, no formal FDA implementation has been issued.
Both components are WADA-banned under S2 (peptide hormones, growth factors, related substances and mimetics). Detection methods are established. Any tested athlete using the stack faces sanction. Out-of-competition and in-competition prohibition applies.
See each compound's individual profile for full regulatory detail, including the commercial and regulatory history, specific Category 2 listing dates, and the pending RFK reclassification scope.
Cost & Access
Not approved for human use. Available through research-chemical suppliers for laboratory research purposes only. U.S. compounding pharmacies cannot legally compound the components under current FDA bulk-substance rules, pending the RFK Jr. reclassification.
The two-vial standard protocol (100 mcg CJC + 200 mcg Ipamorelin daily at bedtime, 5 on / 2 off, 8–12 week cycle) consumes approximately 5 mg CJC-1295 per 10 weeks and 10 mg Ipamorelin per 10 weeks. Practical vendor supply is typically 5 mg vials of each. Independent third-party COA (HPLC + mass spec) is the minimum verification standard — Ipamorelin in particular has documented product-quality variance across the research-chemical market, and CJC-1295 no-DAC is easily mislabeled as DAC-modified. Both concerns are particular to this stack and elevate sourcing discipline above most other compounds on this database.
Following any future FDA reclassification to Category 1, 503A/503B compounding access could return; the legitimate-pathway price is likely to be substantially higher than current gray-market pricing.
Estimated pricing as of April 2026. Actual costs vary by provider, location, and prescription status. Kalios does not sell compounds.
Related Compounds
People researching the GH Stack often also look at these:
Potent ghrelin-receptor agonist with cardioprotective signaling but rapid receptor desensitization.
Second-generation growth hormone releasing peptide. Stronger GH pulse than ipamorelin with mild prolactin rise.
Ghrelin-receptor agonist with strong appetite-stimulating effect alongside GH release.
Recombinant human growth hormone (somatropin). 191-amino-acid protein used for GH deficiency and off-label performance.
Long-arginine-3 insulin-like growth factor 1. Extended half-life IGF-1 analogue. Anabolic and pro-hypertrophic.
Key References
- Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab. 2006;91(3):799-805. PMID: 16352683. (CJC-1295 DAC form; foundational pharmacology.)
- Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. J Clin Endocrinol Metab. 2006;91(12):4792-4797. PMID: 16982668.
- Raun K, Hansen BS, Johansen NL, Thøgersen H, Madsen K, Ankersen M, Andersen PH. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552-561. PMID: 9849822. (Ipamorelin discovery and selectivity.)
- Gobburu JV, Agersø H, Jusko WJ, Ynddal L. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. 1999;16(9):1412-1416. PMID: 10496657.
- Alba M, Fintini D, Sagazio A, Lawrence B, Castaigne JP, Frohman LA, Salvatori R. Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse. Am J Physiol Endocrinol Metab. 2006;291(6):E1290-E1294. PMID: 16895898.
- Walker RF. Sermorelin: a better approach to management of adult-onset growth hormone insufficiency? Clin Interv Aging. 2006;1(4):307-308. PMID: 18046908.
- Bowers CY, Granda R, Mohan S, Kuipers J, Baylink D, Veldhuis JD. Sustained elevation of pulsatile growth hormone (GH) secretion and insulin-like growth factor I (IGF-I) by continuous GH-releasing peptide-2 infusion in older men and women. J Clin Endocrinol Metab. 2004;89(5):2290-2300. PMID: 15126555.
- Svensson J, Lönn L, Jansson JO, Murphy G, Wyss D, Krupa D, Cerchio K, Polvino W, Gertz B, Boseaus I, Sjöström L, Bengtsson BA. Two-month treatment of obese subjects with the oral growth hormone (GH) secretagogue MK-677 increases GH secretion, fat-free mass, and energy expenditure. J Clin Endocrinol Metab. 1998;83(2):362-369. PMID: 9467542.
- Veldhuis JD, Bowers CY. Integrating GHS into the Ghrelin System. Int J Pept. 2010;2010:879503. PMID: 20798846.
- Sinha DK, Balasubramanian A, Tatem AJ, Rivera-Mirabal J, Yu J, Kovac J, Pastuszak AW, Lipshultz LI. Beyond the androgen receptor: the role of growth hormone secretagogues in the modern management of body composition in hypogonadal males. Transl Androl Urol. 2020;9(Suppl 2):S149-S159. PMID: 32257854.
- Sackmann-Sala L, Ding J, Frohman LA, Kopchick JJ. Activation of the GH/IGF-1 axis by CJC-1295, a long-acting GHRH analog, results in serum protein profile changes in normal adult subjects. Growth Horm IGF Res. 2009;19(6):471-477. PMID: 19467606.
- Johansen PB, Segard HB, Nedergaard L, Thorsted B, Raun K, Hansen BS. The growth hormone-releasing properties of ipamorelin compared to GHRP-6 in the conscious rat. Eur J Endocrinol. 1998;139:552-561. (Supportive preclinical selectivity data.)
- FDA. Bulk Drug Substances That Raise Significant Safety Risks (Category 2) — 503A / 503B Compounding. FDA.gov, updated 2025.
- HHS Secretary Robert F. Kennedy Jr. Public Statement on Peptide Reclassification, February 27, 2026. (Announcement of planned reclassification of 14 of 19 Category 2 peptides.)
- WADA. 2026 Prohibited List. Section S2 — peptide hormones, growth factors, related substances and mimetics. World Anti-Doping Agency.
Last updated: April 2026 | Profile authored by Kalios Peptides research team