Side-by-side · Research reference

GHRP-2vsSS-31

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

APhase 2Reviewed15/42 cited

BPhase 3Reviewed9/43 cited

GHRP-2

Hexapeptide GHRP · Phase 2 (clinical diagnostic)

100–300 mcgPer doseBowers 1990

Phase 2Evidence levelBowers 1990 Sigalos 2018

~30 minHalf-lifeMalagón 1999

SQ · Multiple sites · 1–3×/day

SS-31

Cardiolipin-binding · Mitochondrial protective

40 mgDaily doseSzeto 2014

Phase 3Evidence levelSzilagyi 2009 Szeto 2014

~3 hrHalf-life

SQ · Abdomen · Once daily

01Mechanism of Action

Parameter

GHRP-2

SS-31

Primary target

Ghrelin receptor (GHS-R1a) on anterior pituitaryBowers 1990

Cardiolipin in inner mitochondrial membraneSzeto 2014

Pathway

GHS-R1a → Gαq → Ca²⁺ → GH vesicle exocytosisBowers 2002

Cardiolipin binding → cristae stabilisation → ETC integrity → reduced ROS + preserved ATP synthesisSzeto 2014 Szilagyi 2009

Downstream effect

Strong GH pulse + IGF-1 elevation; appetite increase via ghrelin agonismBowers 2002

Mitochondrial bioenergetic preservation; cardio-, neuro-, and reno-protective effects in animal + clinical studiesSzeto 2014

Feedback intact?

Yes, with somatostatin feedback active

—

Origin

Synthetic hexapeptide; developed by Bowers/Tulane group in the 1980sBowers 1990

Synthetic tetrapeptide D-Arg-Dmt-Lys-Phe-NH₂; cell-permeable, mitochondrial-selectiveSzeto 2014

Antibody development

—

02Dosage Protocols

Parameter

GHRP-2

SS-31

Standard dose

100–300 mcg per injectionBowers 1990

40 mg / day SQ (clinical trials)Szeto 2014

Anecdotal community range 5-10 mg/day. Phase 3 trials use 40 mg.

Frequency

1–3× per day

Once daily

Lower / starter dose

50 mcg per dose

5 mg / day (anecdotal)

Evidence basis

Phase 2 + clinical diagnostic useBowers 1990

Multiple Phase 3 trials (Barth, AMD, ischemia-reperfusion)Szeto 2014 Szilagyi 2009

Duration

8–12 weeks on / 4 off (anecdotal)

Indefinite for mitochondrial disease; cycled for healthspan use

Reconstitution

Bacteriostatic water

Timing

Pre-sleep + fasted preferred

Morning fasted preferred; pre-workout for exercise-induced mitochondrial stress

Half-life

~30 minMalagón 1999

~3 h plasma; tissue uptake longer

04Side Effects & Safety

Parameter

GHRP-2

SS-31

Cortisol elevation

Mild but measurableBowers 1990

—

Prolactin elevation

Mild but measurable

—

Hunger

Strong appetite increase

—

Injection site reaction

Mild erythema

Erythema, mild pruritus

IGF-1 elevation

Strong; monitor with chronic high-dose use

—

Cancer risk

Contraindicated in active malignancy

—

Pregnancy / OB

Avoid

Avoid — insufficient data

GI symptoms

—

Nausea (uncommon)

Headache

—

Reported in some Phase 3 trials

Cardiovascular

—

Cardio-protective in studies; no signal of harm

Long-term safety

—

Phase 3 data over 24+ months; no major safety signalsSzeto 2014

Absolute Contraindications

GHRP-2

·Active malignancy
·Pregnancy / breastfeeding

SS-31

·Pregnancy / breastfeeding
·Hypersensitivity to peptide

Relative Contraindications

GHRP-2

·Untreated diabetes

SS-31

·None established

05Administration Protocol

Parameter

GHRP-2

SS-31

1. Reconstitution

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL.

Add bacteriostatic water per label. Light-protected handling.

2. Injection site

SQ — abdomen or thigh. Rotate sites.

3. Timing

Pre-sleep + fasted preferred.

Morning fasted; pre-workout for exercise-augmented mitochondrial stress.

4. Storage

Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.

Lyophilised: refrigerate, light-protected. Reconstituted: refrigerate ≤30 days.

5. Needle

29–31G, 4–8 mm insulin syringe.

06Stack Synergy

GHRP-2

+ CJC-1295 (no DAC)

Strong

View CJC-1295 (no DAC) →

GHRP-2 + CJC-1295-no-DAC is a higher-amplitude alternative to the ipamorelin + CJC-1295 stack. GHRP-2 produces a stronger pulse but with cortisol + prolactin signal — choose when maximum GH amplitude is the goal and the side-effect tolerance is acceptable.

GHRP-2: 100–200 mcg SQ · pre-sleep
CJC-1295 (no DAC): 100 mcg SQ · same injection
Primary benefit: High-amplitude GH pulse, body composition

Bowers 1990 Teichman 2006

SS-31

+ MOTS-c

Moderate

View MOTS-c →

SS-31 and MOTS-c address mitochondrial decline through complementary axes. SS-31 protects existing mitochondrial structure (cardiolipin binding, cristae stabilisation). MOTS-c upregulates AMPK/PGC-1α, triggering biogenesis of new mitochondria. Together they pair preservation with renewal — anecdotally favoured in healthspan and post-cardio-event recovery protocols.

SS-31: 5–10 mg SQ · daily morning
MOTS-c: 5 mg SQ · 2× per week pre-workout
Primary benefit: Mitochondrial preservation + biogenesis