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GHRP-6 vs GHRP-2 side-by-side

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GHRP-6GHRP-2

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Property	GHRP-6	GHRP-2
Category	Growth Hormone	Growth Hormone
Also known as	Growth Hormone Releasing Peptide 6, SKF-110679	Growth Hormone Releasing Peptide 2, Pralmorelin, KP-102
FDA approved	No	No
Clinical status	Preclinical/investigational; source notes FDA Category 2 compounding restriction concerns Pre Preclinical I Phase I II Phase II III Phase III IV Phase IV FDA FDA approved	Approved in some countries for growth hormone deficiency diagnosis; not FDA approved and listed as FDA Category 2 restricted in the source. Pre Preclinical I Phase I II Phase II III Phase III IV Phase IV FDA FDA approved
What to expect	Appetite stimulation, muscle building, GH release	Growth hormone release, muscle gain, recovery
How it works	GHRP-6 is reported to act as an agonist at GHS-R1a, the growth hormone secretagogue receptor associated with ghrelin biology. The source links receptor activation in pituitary and hypothalamic pathways to growth hormone pulse release. It also notes that GHS-R1a involvement in NPY/AgRP appetite circuitry may contribute to GHRP-6's prominent hunger effect, and that higher doses may raise cortisol and prolactin.	GHRP-2 is reported to act at GHS-R1a, the ghrelin or growth hormone secretagogue receptor. The supplied evidence places the relevant signaling in pituitary and hypothalamic pathways and links receptor activation to a pulsatile release of growth hormone. The source also notes that appetite and other hormonal effects may still occur because the ghrelin system is involved.
Typical dosing	100-300 mcg 2-3x daily · 2-3x daily · Subcutaneous injection	100-300 mcg 2-3x daily · 2-3x daily
Research dosing	100-300 mcg per injection · 8-12 weeks · Subcutaneous injection, reported as fasted	100-300 mcg per injection · 8-12 weeks · Subcutaneous injection
Typical duration	8-12 weeks	8-12 weeks
Administration	Subcutaneous injection, reported with fasted timing	Slow intravenous injection for the approved Japanese diagnostic test; subcutaneous administration is investigational.
Timing	Reported timing: fasted morning use or before bed Source reports empty-stomach or fasted timing	Before bed or morning while fasted Empty-stomach timing reported
Evidence level	Clinical Trials	Clinical Trials
Possible side effects	Significant hunger increase (Source describes this as especially pronounced among GHRPs.) Water retention (Reported by source; severity not quantified.) Elevated cortisol levels (Source notes this concern, particularly at higher doses.) +6 more Elevated prolactin levels (Source notes this concern, particularly at higher doses.) Flushing (Reported by source; severity not quantified.) Nausea (Reported by source; severity not quantified.) Headache (Reported by source; severity not quantified.) Possible histamine release (Source advises caution for MCAS or histamine sensitivity, but does not quantify risk.) Limited long-term safety data (Source indicates long-term safety evidence is limited.)	Increased appetite (Reported as less pronounced than with GHRP-6 in the source.) Water retention Fatigue +5 more Headache Nausea Possible cortisol and prolactin elevation (Source notes this as a concern, reportedly less than with GHRP-6.) Possible histamine release (Source advises caution in the context of MCAS or histamine sensitivity.) Active malignancy contraindication (Listed as contraindicated with active malignancies in the source.)
Research summary	The supplied source describes GHRP-6 as a research tool studied in humans, mainly for laboratory or diagnostic investigation of growth hormone release rather than as a validated therapeutic intervention. It notes early research showing growth hormone release, and connects investigation of this peptide class to the later identification of ghrelin. A cited 2013 pharmacokinetic study in nine healthy men is summarized as finding very low oral bioavailability and an elimination half-life of about 2.5 hours. The source states that popular fitness-related outcome claims such as muscle gain, fat loss, and healing lack controlled human outcome-trial support, and it reiterates that GHRP-6 is not FDA or EMA approved.	The source describes the strongest human evidence for GHRP-2 as its diagnostic role rather than wellness or body-composition use. It reports phase II development and approval in Japan as pralmorelin for growth hormone deficiency testing, including pediatric short-stature contexts. It also cites a human pharmacology study in ten male volunteers where GHRP-2 and metabolite AA-3 were detected in urine after intravenous administration, with anti-doping relevance because the compound is banned in sport. The source does not present solid controlled-trial support for marketed anti-aging, recovery, or body-composition claims.
References	Source Source +1 more Source	PubMed PubMed +1 more Wiley Online Library
Full profile	View Details	View Details

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Educational use only. This information is aggregated from public research and community reports. It is not medical advice, and dosing details are descriptive, not recommendations. Always consult a qualified healthcare professional.

Property

GHRP-6

GHRP-2

Category

Growth Hormone

Also known as

Growth Hormone Releasing Peptide 6, SKF-110679

Growth Hormone Releasing Peptide 2, Pralmorelin, KP-102

FDA approved

Clinical status

Preclinical/investigational; source notes FDA Category 2 compounding restriction concerns

Pre
Preclinical
I
Phase I
II
Phase II
III
Phase III
IV
Phase IV
FDA
FDA approved

Approved in some countries for growth hormone deficiency diagnosis; not FDA approved and listed as FDA Category 2 restricted in the source.

Pre
Preclinical
I
Phase I
II
Phase II
III
Phase III
IV
Phase IV
FDA
FDA approved

What to expect

Appetite stimulation, muscle building, GH release

Growth hormone release, muscle gain, recovery

How it works

GHRP-6 is reported to act as an agonist at GHS-R1a, the growth hormone secretagogue receptor associated with ghrelin biology. The source links receptor activation in pituitary and hypothalamic pathways to growth hormone pulse release. It also notes that GHS-R1a involvement in NPY/AgRP appetite circuitry may contribute to GHRP-6's prominent hunger effect, and that higher doses may raise cortisol and prolactin.

GHRP-2 is reported to act at GHS-R1a, the ghrelin or growth hormone secretagogue receptor. The supplied evidence places the relevant signaling in pituitary and hypothalamic pathways and links receptor activation to a pulsatile release of growth hormone. The source also notes that appetite and other hormonal effects may still occur because the ghrelin system is involved.

Typical dosing

100-300 mcg 2-3x daily · 2-3x daily · Subcutaneous injection

100-300 mcg 2-3x daily · 2-3x daily

Research dosing

100-300 mcg per injection · 8-12 weeks · Subcutaneous injection, reported as fasted

100-300 mcg per injection · 8-12 weeks · Subcutaneous injection

Typical duration

8-12 weeks

Administration

Subcutaneous injection, reported with fasted timing

Slow intravenous injection for the approved Japanese diagnostic test; subcutaneous administration is investigational.

Timing

Reported timing: fasted morning use or before bed

Source reports empty-stomach or fasted timing

Before bed or morning while fasted

Empty-stomach timing reported

Evidence level

Clinical Trials

Possible side effects

Significant hunger increase (Source describes this as especially pronounced among GHRPs.)
Water retention (Reported by source; severity not quantified.)
Elevated cortisol levels (Source notes this concern, particularly at higher doses.)

+6 more

Elevated prolactin levels (Source notes this concern, particularly at higher doses.)
Flushing (Reported by source; severity not quantified.)
Nausea (Reported by source; severity not quantified.)
Headache (Reported by source; severity not quantified.)
Possible histamine release (Source advises caution for MCAS or histamine sensitivity, but does not quantify risk.)
Limited long-term safety data (Source indicates long-term safety evidence is limited.)

Increased appetite (Reported as less pronounced than with GHRP-6 in the source.)
Water retention
Fatigue

+5 more

Headache
Nausea
Possible cortisol and prolactin elevation (Source notes this as a concern, reportedly less than with GHRP-6.)
Possible histamine release (Source advises caution in the context of MCAS or histamine sensitivity.)
Active malignancy contraindication (Listed as contraindicated with active malignancies in the source.)

Research summary

The supplied source describes GHRP-6 as a research tool studied in humans, mainly for laboratory or diagnostic investigation of growth hormone release rather than as a validated therapeutic intervention. It notes early research showing growth hormone release, and connects investigation of this peptide class to the later identification of ghrelin. A cited 2013 pharmacokinetic study in nine healthy men is summarized as finding very low oral bioavailability and an elimination half-life of about 2.5 hours. The source states that popular fitness-related outcome claims such as muscle gain, fat loss, and healing lack controlled human outcome-trial support, and it reiterates that GHRP-6 is not FDA or EMA approved.

The source describes the strongest human evidence for GHRP-2 as its diagnostic role rather than wellness or body-composition use. It reports phase II development and approval in Japan as pralmorelin for growth hormone deficiency testing, including pediatric short-stature contexts. It also cites a human pharmacology study in ten male volunteers where GHRP-2 and metabolite AA-3 were detected in urine after intravenous administration, with anti-doping relevance because the compound is banned in sport. The source does not present solid controlled-trial support for marketed anti-aging, recovery, or body-composition claims.

References

+1 more

+1 more

Full profile