Side-by-side · Research reference

CJC-1295 (no DAC)vsGonadorelin

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 1HUMAN-REVIEWED15/51 cited

BFDA-ApprovedHUMAN-REVIEWED7/61 cited

CJC-1295 (no DAC)

Short-acting GHRH · No DAC variant

100 mcgPer doseTeichman 2006

~30 minHalf-lifeIonescu 2006

Phase 1Evidence levelTeichman 2006 Sigalos 2018

SQ · Pre-sleep · 1–2×/day

Gonadorelin

GnRH Analogue · Diagnostic & Therapeutic

90 minPulsatile interval

73%Ovulation restorationTadesse 2026

2–4 minPlasma half-life

IV / SQ · Pulsatile Pump (Therapeutic) · Single Bolus (Diagnostic)

01Mechanism of Action

Parameter

CJC-1295 (no DAC)

Gonadorelin

Primary target

Pituitary GHRH receptorTeichman 2006

GnRH receptors on anterior pituitary gonadotropes

Pathway

GHRH-R → Gαs → cAMP → PKA → GH vesicle exocytosisTeichman 2006

GnRH → Pituitary gonadotrope → LH/FSH secretion → Gonadal steroidogenesisSharma 2026

Downstream effect

Pulsatile GH release matching physiological pattern; subsequent IGF-1 elevationIonescu 2006

Pulsatile LH/FSH release stimulates testicular testosterone or ovarian estradiol/progesterone synthesis; initiates folliculogenesis and spermatogenesisRobin 2026 Sharma 2026

Feedback intact?

Yes — short pulse preserves somatostatin negative feedbackIonescu 2006

Yes — pulsatile delivery preserves negative feedback loops; continuous exposure desensitizes receptors

Origin

Modified human GRF 1-29 with four substitutions (D-Ala²/Gln⁸/Ala¹⁵/Leu²⁷) for protease resistanceTeichman 2006

Synthetic decapeptide (pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2) identical to native hypothalamic GnRH

Antibody development

Not reported in short-term studies

—

02Dosage Protocols

Parameter

CJC-1295 (no DAC)

Gonadorelin

Standard dose

100 mcg per injectionTeichman 2006

Often paired with ipamorelin in same syringe.

—

Frequency

1–2× daily (pre-sleep ± morning)

—

Lower / starter dose

50 mcg per dose

—

Evidence basis

Phase 1 (CJC-1295 with DAC); analog dataTeichman 2006 Ionescu 2006

No-DAC variant is less studied directly; PK extrapolated from native GHRH.

RCT / Expert consensus

Duration

8–12 weeks on / 4 off (anecdotal)

Continuous until pregnancy achieved or fertility goals met

3–6 month courses typical for ovulation induction.

Reconstitution

Bacteriostatic water

—

Timing

Pre-sleep + fasted preferred

—

Half-life

~30 minIonescu 2006

Short pulse vs CJC-1295-DAC (~8 days). Choose no-DAC for pulsatile, DAC for sustained.

2–4 minutes (plasma)

Necessitates frequent pulsatile administration.

Diagnostic test (pituitary function)

—

100 mcg IV or SQ bolus

Measure baseline LH/FSH, then 30/60/90 min post-injection. Normal response: LH ≥2× baseline.

Therapeutic (hypothalamic hypogonadism)

—

5–20 mcg IV bolus every 90–120 minutes

Requires portable pulsatile pump. Dose individualized to achieve normal gonadotropin pulsatility.Robin 2026

Pulsatile interval

—

90 minutes (females) · 120 minutes (males)

Mimics physiological GnRH pulse frequency.

Route

—

IV preferred (therapeutic) · SQ acceptable (diagnostic)

Alternative protocols

—

Exogenous gonadotropins (hCG/hMG) often preferred due to convenience vs pump requirement

03Metabolic / Fat Loss Evidence

Parameter

CJC-1295 (no DAC)

Gonadorelin

Fat loss mechanism

—

None — gonadorelin acts exclusively on reproductive axis

Indirect metabolic effects

—

Restoration of sex hormones may normalize body composition in hypogonadal states

Effect mediated by downstream testosterone/estradiol, not GnRH itself.

04Side Effects & Safety

Parameter

CJC-1295 (no DAC)

Gonadorelin

Injection site reaction

Erythema, mild pruritus

Erythema, irritation (pulsatile pump catheter site)

Flushing / headache

Common transient effect

—

Cortisol elevation

Minimal at standard doses

—

Prolactin elevation

Minimal

—

Glucose intolerance

Possible at high cumulative doses

—

IGF-1 elevation

Dose-dependent; monitor with chronic use

—

Cancer risk

Contraindicated in active malignancy (GH/IGF-1 axis)

—

Pregnancy / OB

Avoid

—

Headache

—

Common with bolus administration

Nausea / abdominal discomfort

—

Transient, dose-related

Ovarian hyperstimulation syndrome (OHSS)

—

Risk with ovulation induction protocols; monitor follicular development via ultrasound

Multiple gestation

—

Increased risk with fertility protocols (twins ~10–15%)

Anaphylaxis

—

Rare hypersensitivity reaction

Pump malfunction / infection

—

Mechanical failure or catheter-site infection with long-term IV pump use

Receptor desensitization

—

Continuous (non-pulsatile) exposure paradoxically suppresses gonadotropinsRobin 2026

Absolute Contraindications

CJC-1295 (no DAC)

·Active malignancy or cancer history
·Pregnancy / breastfeeding
·Disrupted hypothalamic-pituitary axis

Gonadorelin

·Pregnancy (except therapeutic infertility protocols)
·Hypersensitivity to gonadorelin or excipients
·Hormone-dependent tumors (prostate, breast) — risk of tumor stimulation via sex hormone elevation

Relative Contraindications

CJC-1295 (no DAC)

·Untreated diabetes
·Severe insulin resistance

Gonadorelin

·Ovarian cysts or PCOS (monitor for OHSS)
·Pituitary adenoma or other sellar mass (may worsen with gonadotropin surge)

05Administration Protocol

Parameter

CJC-1295 (no DAC)

Gonadorelin

1. Reconstitution

Add 2 mL bacteriostatic water to 2 mg vial → 1 mg/mL = 100 mcg per 0.1 mL. Roll gently.

Administer 100 mcg IV or SQ bolus. Draw baseline LH/FSH, then at 30, 60, 90 minutes. Normal response: LH ≥2× baseline, FSH modest rise. Blunted response suggests pituitary pathology; exaggerated response may indicate primary hypogonadism.

2. Injection site

Subcutaneous, abdomen or thigh. Rotate sites.

Requires programmable infusion pump with IV catheter. Set pulse interval to 90 min (females) or 120 min (males). Bolus dose 5–20 mcg per pulse. Pump worn continuously; catheter site rotated every 48–72 hrs to prevent infection.

3. Timing

Pre-sleep preferred. Often combined with ipamorelin in the same syringe.

Lyophilised gonadorelin reconstituted with sterile saline or provided diluent. Typically 0.8–3.2 mg dissolved in 8 mL for pump reservoir. Solution stable 7–14 days refrigerated.

4. Storage

Lyophilised: room temp, protected from light. Reconstituted: refrigerate 2–8 °C, use within 30 days.

For fertility protocols: ultrasound follicular tracking + serial estradiol/LH measurements. Adjust pulse dose to achieve mid-follicular LH 5–10 IU/L. Ovulation confirmed by progesterone rise or ultrasound.

5. Needle

29–31G, 4–8 mm insulin syringe.

Pulsatile therapy initiated at any point in cycle. Diagnostic test performed in morning (higher baseline LH). For ovulation induction, treatment begins early follicular phase.

06Stack Synergy

CJC-1295 (no DAC)

+ Ipamorelin

Strong

View Ipamorelin →

CJC-1295 (no DAC) and ipamorelin are the canonical "GHRH + GHRP" dual-axis stack at physiological timing. Both peak within 30 min and clear within 2 hours, producing a sharp, high-amplitude GH pulse closely resembling natural physiology. Preferred over the CJC-1295-DAC + ipamorelin stack when pulsatility (vs sustained elevation) is the goal.

CJC-1295 (no DAC): 100 mcg SQ · pre-sleep
Ipamorelin: 200–300 mcg SQ · same injection
Primary benefit: Pulsatile GH stimulation, recovery, body composition

Teichman 2006 Raun 1998

Gonadorelin

+ hCG (Human Chorionic Gonadotropin)

Multi-pathway

View hCG (Human Chorionic Gonadotropin) →

In hypogonadotropic hypogonadism protocols, gonadorelin restores pituitary LH/FSH pulsatility, while exogenous hCG directly stimulates Leydig cells (acting as LH mimetic) to maintain testosterone production. This dual approach ensures both central axis restoration and immediate gonadal steroidogenesis, preventing testicular atrophy during fertility treatment. hCG's longer half-life (24–36 hrs) complements gonadorelin's pulsatile short-acting profile.

Gonadorelin: 5–10 mcg IV every 120 min (pulsatile pump)
hCG: 1500–2000 IU SQ · 2–3× per week
Duration: 12–24 weeks for spermatogenesis induction
Primary benefit: Fertility restoration in hypothalamic hypogonadism with maintained testicular function