Side-by-side · Research reference

HCGvsIpamorelin

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

AFDA-ApprovedHUMAN-REVIEWED12/52 cited

BPhase 1HUMAN-REVIEWED21/57 cited

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

Ipamorelin

Selective GHRP · Ghrelin Mimetic

200–300 mcgPer doseRaun 1998

Phase 1Evidence levelRaun 1998 Sigalos 2018

~2 hrHalf-lifeRaun 1998

SQ · Multiple sites · 1–3×/day

01Mechanism of Action

Parameter

HCG

Ipamorelin

Primary target

LH receptors on testicular Leydig cellsSchröder-Lange 2025

Ghrelin receptor (GHS-R1a) on anterior pituitaryRaun 1998

Pathway

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

GHS-R1a binding → Gαq/11 → ↑intracellular Ca²⁺ → GH vesicle exocytosisRaun 1998 Bowers 1991

Downstream effect

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

GH pulse amplification, IGF-1 elevation, recovery and lipolytic effectsBowers 2002

Feedback intact?

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

Yes — pulsatile pattern preserved; somatostatin feedback activeBowers 2002

Origin

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

Pentapeptide H-Aib-His-D-2-Nal-D-Phe-Lys-NH₂; rationally designed for ghrelin-receptor selectivityRaun 1998

Antibody development

Rare with recombinant; possible with urinary-derived formulations

Not reported in short-term studies

02Dosage Protocols

Parameter

HCG

Ipamorelin

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

—

Evidence basis

RCT / Meta-analysis / FDA-approvedKonsam 2026 Huijben 2026

Phase 1 + clinical practiceRaun 1998 Sigalos 2018

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

—

Standard dose

—

200–300 mcg per injectionRaun 1998

Anecdotal community range; clinical doses 1–3 mg IV in trials.

Frequency

—

1–3× per day

Once daily pre-sleep is most common; twice or thrice for advanced users.

Lower / starter dose

—

100 mcg per dose

Duration

—

8–12 weeks on / 4 weeks off (anecdotal)

GHS-R desensitisation reported with continuous dosing.

Reconstitution

—

Bacteriostatic water; typical 2 mL per 5 mg vial

Timing

—

Pre-sleep + fasted preferred; 30 min away from food

Half-life

—

~2 hoursRaun 1998

Longer than GHRP-6 (15 min); shorter than CJC-1295-DAC (~8 days).

04Side Effects & Safety

Parameter

HCG

Ipamorelin

Injection site reaction

Pain, erythema (mild, transient)

Mild irritation possible

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

—

Cortisol elevation

—

Negligible vs other GHRPsRaun 1998

Prolactin elevation

—

NegligibleRaun 1998

Hunger

—

Mild appetite increase via ghrelin-receptor crosstalk

GH excess (overdose)

—

Joint pain, edema, insulin resistance

IGF-1 elevation

—

Dose-dependent; monitor with chronic high-dose use

Cancer risk

—

Theoretical via GH/IGF-1 axis; contraindicated in active malignancy

Pregnancy / OB

—

Avoid

Absolute Contraindications

HCG

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

Ipamorelin

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

Relative Contraindications

HCG

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

Ipamorelin

·Untreated diabetes
·Severe insulin resistance
·Concurrent corticosteroid use (theoretical desensitisation)

05Administration Protocol

Parameter

HCG

Ipamorelin

1. Reconstitution (if lyophilized)

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.

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL. Roll gently. Solution should be clear.

2. Injection site

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

Subcutaneous, abdomen or thigh. Rotate sites. Pinch fat for shallow SQ delivery.

3. Timing

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

Pre-sleep optimal — aligns with natural GH pulse. Some protocols add a morning fasted dose.

4. Storage

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

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

5. Needle selection

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

29–31G, 4–8 mm insulin syringe.

06Stack Synergy

HCG

— no documented stacks

Ipamorelin

+ Tesamorelin

Strong

View Tesamorelin →

Ipamorelin (GHRP) + tesamorelin (GHRH analogue) is the textbook dual-axis GH stack. They activate two distinct pituitary receptors — the ghrelin receptor and the GHRH receptor — producing a synergistic GH pulse larger than either alone. Ipamorelin's selectivity (no cortisol/prolactin spike) makes it the ideal GHRP partner for long-term protocols.

Ipamorelin: 200–300 mcg SQ · pre-sleep
Tesamorelin: 2 mg SQ · same injection · pre-sleep
Primary benefit: Maximal GH pulsatility, fat loss, recovery, sleep depth

Raun 1998 Bowers 2002

+ CJC-1295 (no DAC)

Strong

View CJC-1295 (no DAC) →

CJC-1295 (no DAC) is a short-acting GHRH analogue. Combined with ipamorelin (GHRP), the pulse is amplified across both receptor systems with timing similar to native physiology. Without the DAC modification, the stack maintains sharp peaks rather than the sustained elevation seen with CJC-1295-DAC + ipamorelin.

Ipamorelin: 200–300 mcg SQ · pre-sleep
CJC-1295 (no DAC): 100 mcg SQ · same injection
Primary benefit: Pulsatile GH stimulation matching physiological pattern

Teichman 2006 Ionescu 2006