Side-by-side · Research reference

CJC-1295 (no DAC)vsHGH 191AA

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-REVIEWED0/75 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

HGH 191AA

Recombinant hGH · FDA-Approved

0.024–0.034 mg/kg/dayPediatric GHD dose

2–4 hoursPlasma half-life

191 AASequence length

SQ · Daily · Evening preferred

01Mechanism of Action

Parameter

CJC-1295 (no DAC)

HGH 191AA

Primary target

Pituitary GHRH receptorTeichman 2006

Growth hormone receptor (GHR) — JAK2/STAT5 pathway

Pathway

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

GHR activation → JAK2/STAT5 → liver IGF-1 synthesis + direct metabolic effects

Downstream effect

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

Linear growth, lipolysis, protein synthesis, nitrogen retention, carbohydrate metabolism modulation

Feedback intact?

Yes — short pulse preserves somatostatin negative feedbackIonescu 2006

No — exogenous GH bypasses hypothalamic-pituitary axis, suppresses endogenous pulsatility

Origin

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

Recombinant DNA technology — 191 AA, identical to pituitary hGH, no methionyl residue

Antibody development

Not reported in short-term studies

Rare — <2% develop binding antibodies, typically non-neutralizing

02Dosage Protocols

Parameter

CJC-1295 (no DAC)

HGH 191AA

Standard dose

100 mcg per injectionTeichman 2006

Often paired with ipamorelin in same syringe.

—

Frequency

1–2× daily (pre-sleep ± morning)

Once daily, typically evening

Evening administration mimics physiological GH pulse.

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.

FDA-approved / decades of RCT data

Duration

8–12 weeks on / 4 off (anecdotal)

Years (children until epiphyseal closure); indefinite (adult GHD)

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.

—

Pediatric GHD

—

0.024–0.034 mg/kg/day SQ

6–7× per week dosing typical. Brand-specific ranges.

Adult GHD

—

0.004–0.016 mg/kg/day SQ

Start low, titrate based on IGF-1 levels.

Turner syndrome

—

0.045–0.050 mg/kg/day SQ

Idiopathic short stature

—

0.037 mg/kg/day SQ

AIDS wasting

—

0.1 mg/kg/day SQ (high-dose)

Short-term indication. Monitor glucose.

Monitoring

—

IGF-1, glucose, thyroid function, bone age (children)

03Metabolic / Fat Loss Evidence

Parameter

CJC-1295 (no DAC)

HGH 191AA

Primary fat target

—

Visceral and subcutaneous adipose tissue

Mechanism

—

Lipolysis via hormone-sensitive lipase activation, FFA oxidation

Effect on lean mass

—

Significant lean mass increase (protein synthesis, nitrogen retention)

Insulin sensitivity

—

Acute insulin resistance (anti-insulin effect); chronic neutral-to-improved via fat loss

IGF-1 elevation

—

Dose-dependent, significant — primary anabolic mediator

Glucose metabolism

—

Hyperglycemia risk, especially high doses (AIDS wasting)

Body composition

—

↓ fat mass, ↑ lean mass, ↑ bone mineral density (children)

Clinical context

—

FDA-approved for AIDS wasting (cachexia). Off-label use for body recomposition lacks long-term safety data.

04Side Effects & Safety

Parameter

CJC-1295 (no DAC)

HGH 191AA

Injection site reaction

Erythema, mild pruritus

Lipohypertrophy, lipoatrophy, erythema (rotate sites)

Flushing / headache

Common transient effect

—

Cortisol elevation

Minimal at standard doses

—

Prolactin elevation

Minimal

—

Glucose intolerance

Possible at high cumulative doses

Hyperglycemia, new-onset diabetes (anti-insulin effect)

IGF-1 elevation

Dose-dependent; monitor with chronic use

—

Cancer risk

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

Contraindicated in active malignancy. Theoretical risk in cancer survivors (controversial).

Pregnancy / OB

Avoid

—

Fluid retention / Edema

—

Peripheral edema, arthralgia, carpal tunnel syndrome (dose-dependent)

Intracranial hypertension

—

Benign intracranial hypertension (pseudotumor cerebri) — headache, visual changes, papilledema

Slipped capital femoral epiphysis

—

SCFE risk in children — limp, hip/knee pain (requires surgery)

Scoliosis progression

—

Rapid growth may unmask/progress scoliosis (monitor spine in children)

Hypothyroidism

—

Central hypothyroidism unmasking or worsening (monitor TSH, free T4)

Antibody formation

—

Rare (<2%), typically non-neutralizing. Loss of efficacy if neutralizing antibodies develop.

Pancreatitis

—

Rare. Higher risk in children with certain syndromes (Prader-Willi).

Gynecomastia

—

Adolescent males (physiological during puberty, may be exacerbated)

Absolute Contraindications

CJC-1295 (no DAC)

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

HGH 191AA

·Active malignancy or history of cancer (especially childhood cancer survivors with risk factors)
·Acute critical illness (post-cardiac surgery, trauma, acute respiratory failure)
·Diabetic retinopathy (active proliferative or severe non-proliferative)
·Prader-Willi syndrome with severe obesity, sleep apnea, or respiratory impairment
·Closed epiphyses (for growth indications)

Relative Contraindications

CJC-1295 (no DAC)

·Untreated diabetes
·Severe insulin resistance

HGH 191AA

·Diabetes mellitus (monitor closely, may require insulin adjustment)
·Intracranial lesions or history of intracranial hypertension
·Scoliosis (monitor curve progression)
·Untreated hypothyroidism (treat before GH initiation)
·Severe obesity (assess OSA risk, cardiovascular status)

05Administration Protocol

Parameter

CJC-1295 (no DAC)

HGH 191AA

1. Reconstitution

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

Add diluent (sterile water or bacteriostatic water per manufacturer) to vial. Swirl gently — do not shake. Solution should be clear, colorless. Concentration varies by brand (e.g., 5 mg or 10 mg per vial).

2. Injection site

Subcutaneous, abdomen or thigh. Rotate sites.

Subcutaneous — rotate sites: abdomen, thigh, buttocks, upper arm. Avoid same site within 1 cm for 2 weeks to prevent lipodystrophy.

3. Timing

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

Once daily, evening preferred (6–8 PM or pre-sleep). Mimics physiological nocturnal GH secretion. Consistency is critical.

4. Storage

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

Unreconstituted: refrigerate 2–8 °C, protect from light. Reconstituted: refrigerate, use within 14–28 days (brand-specific). Do not freeze.

5. Needle

29–31G, 4–8 mm insulin syringe.

27–31G, 4–8 mm insulin syringe or pen device. Pinch skin, 45–90° angle depending on subcutaneous thickness.

6. Monitoring

—

Baseline and periodic: IGF-1 (target age/sex-adjusted midrange), fasting glucose, HbA1c, thyroid function (TSH, free T4), bone age (children), lipid panel. Fundoscopy if headache/visual symptoms.

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

HGH 191AA

+ Ipamorelin

Moderate

View Ipamorelin →

Ipamorelin (GHRP) stimulates endogenous GH release, which is redundant when exogenous rhGH is administered. However, ipamorelin may still amplify pulsatility of remaining endogenous secretion in partial GHD or during GH dose titration. Not typically combined in standard clinical practice; more common in experimental or off-label protocols. Limited evidence for additive benefit.

HGH 191AA: Standard dose per indication
Ipamorelin: 100–200 mcg SQ · morning (if used)
Note: Monitor IGF-1 closely; avoid supraphysiological levels
Primary benefit: Theoretical enhancement of pulsatility; limited clinical rationale

+ Tesamorelin

Weak

View Tesamorelin →

Tesamorelin (GHRH analogue) stimulates endogenous GH secretion, which is unnecessary when exogenous rhGH is already provided. Combining both offers no mechanistic advantage and increases cost, side effects, and IGF-1 elevation risk. Not recommended in clinical practice.

Note: Combination not recommended — choose one GH modality
Primary benefit: None — redundant mechanisms