Side-by-side · Research reference

CJC-1295 (no DAC)vsTirzepatide

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

APhase 1Reviewed15/51 cited

BFDA-ApprovedVerified14/45 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

Tirzepatide

GIP+GLP-1 Dual Agonist · FDA-Approved

2.5–15 mgWeekly doseZEPBOUND (tirzepatide) injecti 2023

20.9%Body-weight ↓Jastreboff 2022

~5 daysHalf-lifeZEPBOUND (tirzepatide) injecti 2023

SQ · Abdomen / thigh / arm · Once weekly

01Mechanism of Action

Parameter

CJC-1295 (no DAC)

Tirzepatide

Primary target

Pituitary GHRH receptorTeichman 2006

GIP receptor (GIPR) + GLP-1 receptor (GLP-1R)Frias 2018

Pathway

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

Dual GIPR/GLP-1R agonism → ↑insulin (glucose-dependent), ↓glucagon, ↓gastric emptying, ↓appetite, ↑energy expenditure (via GIP component)Jastreboff 2022 Frias 2018

Downstream effect

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

Profound glycemic improvement and weight reduction; cardiometabolic benefitsJastreboff 2022

Feedback intact?

Yes — short pulse preserves somatostatin negative feedbackIonescu 2006

Glucose-dependent insulin release preserves physiological feedback

Origin

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

39-AA peptide with C-20 fatty-acid acylation. Single molecule with balanced GIP + GLP-1 affinityFrias 2018

Antibody development

Not reported in short-term studies

—

02Dosage Protocols

Parameter

CJC-1295 (no DAC)

Tirzepatide

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.

FDA-approved · Phase 3 RCTs (SURMOUNT, SURPASS)Jastreboff 2022 ZEPBOUND (tirzepatide) injecti 2023

Duration

8–12 weeks on / 4 off (anecdotal)

Indefinite for chronic indication

Reconstitution

Bacteriostatic water

Pre-filled commercial pen. Research vial: bacteriostatic water per label.

Timing

Pre-sleep + fasted preferred

Once weekly, any time of day

Half-life

~30 minIonescu 2006

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

~5 days (116 h)ZEPBOUND (tirzepatide) injecti 2023

Standard dose (T2D)

—

5–15 mg / weekZEPBOUND (tirzepatide) injecti 2023

Standard dose (weight)

—

5, 10, or 15 mg / week (titrated)ZEPBOUND (tirzepatide) injecti 2023 Jastreboff 2022

Titration schedule

—

2.5 mg → +2.5 mg every 4 weeks → 15 mg max

Slower titration mitigates GI side effects.

04Side Effects & Safety

Parameter

CJC-1295 (no DAC)

Tirzepatide

Injection site reaction

Erythema, mild pruritus

Mild erythema, pruritus

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

Contraindicated

GI symptoms

—

Nausea, vomiting, diarrhea (common, dose-dependent)Jastreboff 2022

Pancreatitis risk

—

Rare; discontinue if suspectedZEPBOUND (tirzepatide) injecti 2023

Thyroid C-cell tumours

—

Boxed warning — contraindicated in MEN2 / MTC historyZEPBOUND (tirzepatide) injecti 2023

Hypoglycemia

—

Low as monotherapy; risk with sulfonylureas / insulin

Gallbladder events

—

Increased cholelithiasis

Diabetic retinopathy

—

Rapid glycemic improvement may transiently worsen

Absolute Contraindications

CJC-1295 (no DAC)

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

Tirzepatide

·MTC personal or family history; MEN2
·Pregnancy / breastfeeding
·Hypersensitivity to tirzepatide

Relative Contraindications

CJC-1295 (no DAC)

·Untreated diabetes
·Severe insulin resistance

Tirzepatide

·Severe gastroparesis
·History of pancreatitis
·Diabetic retinopathy

05Administration Protocol

Parameter

CJC-1295 (no DAC)

Tirzepatide

1. Reconstitution

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

Commercial: pre-filled pen / vial. Research lyophilised: bacteriostatic water per label.

2. Injection site

Subcutaneous, abdomen or thigh. Rotate sites.

SQ — abdomen, thigh, or upper arm. Rotate weekly.

3. Timing

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

Once weekly, same day. Day change allowed if ≥3 days separate doses.

4. Storage

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

Refrigerate 2–8 °C unopened. Room temp ≤30 °C up to 21 days after first use.

5. Needle

29–31G, 4–8 mm insulin syringe.

Pen-supplied. Research vial: 27–31G insulin syringe.

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

Tirzepatide

— no documented stacks