Comparison
GHRP-6 vs Metformin
Side-by-side of GHRP-6 and Metformin. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
GHRP-6
First-generation hexapeptide ghrelin-receptor agonist. Pioneered the GHS-R1a pathway in the 1980s. Produces the strongest hunger response among GHRPs and a mo.
Metformin
Metformin for longevity: biguanide mechanism of action, TAME trial status, anti-aging dosage, weight loss data, life extension evidence in non-diabetics.
Effects at a glance
GHRP-6
- •First-generation hexapeptide ghrelin-receptor agonist; foundational to the GHRP class
- •Strongest appetite stimulation of any synthetic GHRP at equivalent GH doses
- •Produces measurable cortisol and prolactin rise alongside the GH pulse
- •Anecdotal protocols use 100 to 200 mcg subcutaneously 2 to 3 times daily on an empty stomach
- •Largely superseded by ipamorelin (cleaner profile) and GHRP-2 (stronger pulse) for body-composition use
- •Banned by WADA under S2; detection methods validated in accredited labs
Metformin
- •Reduces HbA1c by ~1.0 to 1.5 percentage points in type 2 diabetes; first-line agent in major guidelines
- •DPP trial: 31% reduction in T2DM incidence in adults with prediabetes over 2.8 years
- •Suppresses hepatic gluconeogenesis via AMPK activation and complex I inhibition
- •Long-term use depletes B12; annual monitoring recommended after year 2
- •Lifespan extension in non-diabetic humans is not established; TAME trial pending
- •MASTERS trial reported blunted resistance-training hypertrophy in older adults
Side-by-side
| Attribute | GHRP-6 | Metformin |
|---|---|---|
| Category | peptide | pharmaceutical |
| Also known as | Growth Hormone Releasing Peptide 6, SKF-110679, Histidyl-D-Tryptophyl-Alanyl-Tryptophyl-D-Phenylalanyl-Lysinamide | Glucophage, Fortamet, Glumetza, dimethylbiguanide |
| Half-life (hr) ↗ | 0.5 | 6 |
| Typical dose (mg) ↗ | 0.1 | 1500 |
| Dosing frequency | 2-3x daily | 1 to 3 times daily with meals; XR once daily |
| Routes | subcutaneous, intravenous | oral |
| Onset (hr) | 0.25 | 1 |
| Peak (hr) | 0.5 | 2.5 |
| Molecular weight | 872.44 | 129.16 |
| Molecular formula | C46H56N12O6 | C4H11N5 |
| Mechanism | Hexapeptide agonist of GHS-R1a (ghrelin receptor). Suppresses hypothalamic somatostatin and stimulates pituitary somatotrophs, with strong central NPY/AgRP appetite signaling and modest cortisol and prolactin release. | Suppresses hepatic gluconeogenesis primarily via AMPK activation and complex I inhibition; modestly improves peripheral insulin sensitivity and shifts gut microbiome composition. |
| Legal status | Not FDA approved; research-use-only grey market; banned by WADA | Prescription only (FDA approved for type 2 diabetes 1994) |
| WADA status | banned | allowed |
| DEA / Rx | Not scheduled (research chemical) | Rx only (not a controlled substance) |
| Pregnancy | Insufficient data; not recommended | Category B; used in gestational diabetes and PCOS per current guidance |
| CAS | 87616-84-0 | 657-24-9 |
| PubChem CID | 9919072 | 4091 |
| Wikidata | Q5519921 | Q19484 |
Safety profile
GHRP-6
Common side effects
- intense hunger
- water retention
- vivid dreams
- head pressure or flushing
- tingling at injection site
- transient lethargy
Contraindications
- pregnancy
- active malignancy
- history of pituitary tumor
- uncontrolled diabetes
- prolactin sensitivity
Interactions
- CJC-1295: synergistic GH release; commonly co-administered(minor)
- sermorelin: additive GH release via parallel GHRH and ghrelin pathways(minor)
- insulin: sustained GH can blunt insulin sensitivity over weeks(moderate)
- corticosteroids: blunt GH response and amplify cortisol load(moderate)
Metformin
Common side effects
- nausea
- diarrhea
- abdominal discomfort
- metallic taste
- decreased appetite
- B12 depletion (long-term)
Contraindications
- eGFR below 30 mL/min/1.73m2
- acute or chronic metabolic acidosis
- severe hepatic impairment
- acute heart failure
- iodinated contrast within 48 hours
Interactions
- iodinated contrast media: renal injury risk; hold 48 hours peri-imaging(major)
- alcohol (heavy use): elevated lactic acidosis risk(major)
- cimetidine: raises metformin plasma levels via OCT2 inhibition(moderate)
- insulin and sulfonylureas: additive hypoglycemia risk in combination(moderate)
- dolutegravir: raises metformin exposure via OCT2(moderate)
Which Should You Take?
Metformin comes out ahead for most readers on the criteria we weight: 2 catalogued goals, prescription-only, oral dosing, with a Tier-A outcome catalogued. GHRP-6 is the right call when one of the conditionals below applies.
- → If your priority is growth-hormone axis, pick GHRP-6.
- → If your priority is appetite regulation, pick GHRP-6.
- → If your priority is metabolic health and glucose control, pick Metformin.
- → If your priority is healthspan extension, pick Metformin.
Edge case: If you cannot self-administer injections, Metformin is the only oral option in this pair.
Default choice: Metformin. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for GHRP-6 only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between GHRP-6 and Metformin?
GHRP-6 and Metformin differ in category (peptide vs pharmaceutical), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, GHRP-6 or Metformin?
GHRP-6 half-life is 0.5 hours; Metformin half-life is 6 hours.
Can you stack GHRP-6 with Metformin?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper