Side-by-side · Research reference

CJC-1295 (no DAC)vsHCG

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-REVIEWED12/52 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

HCG

Glycoprotein Hormone · LH Mimetic

2,000 IUTypical dose (2×/wk)Konsam 2026 Zachariou 2026

70–90%Sperm induction rateHuijben 2026 Zachariou 2026

12–24 moTime to sperm appearanceHuijben 2026 Nariyoshi 2025

IM or SQ · 2–3×/week

01Mechanism of Action

Parameter

CJC-1295 (no DAC)

HCG

Primary target

Pituitary GHRH receptorTeichman 2006

LH receptors on testicular Leydig cellsSchröder-Lange 2025

Pathway

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

hCG → Leydig cell LH receptor → Intracellular cAMP → Steroidogenesis pathway activation → Testosterone synthesis

Downstream effect

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

Elevated intratesticular testosterone, restored spermatogenesis, virilization, secondary sex characteristic developmentKonsam 2026 Zachariou 2026

Feedback intact?

Yes — short pulse preserves somatostatin negative feedbackIonescu 2006

No — exogenous hCG bypasses hypothalamic-pituitary axis; endogenous LH remains suppressed

Origin

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

Heterodimeric glycoprotein (alpha subunit shared with LH/FSH/TSH; beta subunit confers specificity). Available as urinary-derived or recombinant formulations.

Antibody development

Not reported in short-term studies

Rare with recombinant; possible with urinary-derived formulations

02Dosage Protocols

Parameter

CJC-1295 (no DAC)

HCG

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 / Meta-analysis / FDA-approvedKonsam 2026 Huijben 2026

Duration

8–12 weeks on / 4 off (anecdotal)

—

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.

—

Hypogonadotropic hypogonadism (monotherapy)

—

2,000 IU IM/SQ 2–3×/weekKonsam 2026 Zachariou 2026

Titrate to normalize testosterone (300–1,000 ng/dL) or achieve target AMH ~7.4 ng/mL.

Combined therapy (hCG + FSH)

—

hCG 2,000 IU 2×/wk + rFSH 75 IU 3×/wkKonsam 2026 Nariyoshi 2025

Preferred for azoospermia; FSH added after initial hCG phase or from outset.

Triple therapy (experimental)

—

hCG 2,000 IU 2×/wk + rFSH 75 IU 3×/wk + testosterone 100 mg IM q2wkKonsam 2026

May accelerate virilization; reduces hCG requirements (~30% lower cumulative dose vs monotherapy).

Cryptorchidism (pediatric)

—

500–4,000 IU IM 2–3×/week for 3–6 weeks

Duration to sperm appearance

—

12–24 months (median ~18 mo)Huijben 2026 Zachariou 2026

Congenital HH may require longer treatment; acquired HH responds faster.

Route

—

Intramuscular or subcutaneousKonsam 2026

Monitoring

—

Serum testosterone, semen analysis q3–6mo, testicular ultrasound

Thickened seminiferous tubules (>300 μm) on ultrasound predict imminent sperm appearance.Nariyoshi 2025

04Side Effects & Safety

Parameter

CJC-1295 (no DAC)

HCG

Injection site reaction

Erythema, mild pruritus

Pain, erythema (mild, transient)

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

—

Gynecomastia

—

Aromatization of elevated testosterone to estradiol; dose-dependent

Testicular discomfort / Edema

—

Rapid testicular growth in hypogonadal males; usually self-limiting

Polycythemia

—

Elevated hematocrit from supraphysiological testosterone; monitor CBC

Mood / Libido changes

—

Variable; usually positive with normalization of testosterone

Acne / Oily skin

—

Androgen-mediated; dose-dependent

Prostate concerns

—

Monitor PSA in older males; hCG restores physiological testosterone (not supraphysiological)

Antibody formation

—

Rare with recombinant; possible with urinary-derived

Absolute Contraindications

CJC-1295 (no DAC)

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

HCG

·Androgen-dependent malignancy (prostate, breast cancer)
·Hypersensitivity to hCG or excipients
·Precocious puberty

Relative Contraindications

CJC-1295 (no DAC)

·Untreated diabetes
·Severe insulin resistance

HCG

·Untreated obstructive sleep apnea
·Severe cardiovascular disease (polycythemia risk)
·History of thromboembolism

05Administration Protocol

Parameter

CJC-1295 (no DAC)

HCG

1. Reconstitution

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

Add sterile water or bacteriostatic water per manufacturer instructions. Typically 1–2 mL per 5,000–10,000 IU vial. Roll gently — do not shake. Solution should be clear.

2. Injection site

Subcutaneous, abdomen or thigh. Rotate sites.

Intramuscular: ventrogluteal, vastus lateralis, or deltoid. Subcutaneous: abdomen, avoiding navel (2-inch radius). Rotate sites to prevent lipohypertrophy.

3. Timing

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

Administer 2–3 times per week. Consistent weekly schedule recommended (e.g., Monday/Thursday or Monday/Wednesday/Friday).

4. Storage

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

Lyophilized: room temperature, light-protected. Reconstituted: refrigerate 2–8 °C. Bacteriostatic water extends shelf life to ~30 days; sterile water use within 72 hours.

5. Needle

29–31G, 4–8 mm insulin syringe.

IM: 21–23G, 1–1.5 inch. SQ: 25–27G, 5/8 inch. Inject slowly (30–60 seconds for IM).

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

HCG

— no documented stacks