The short answer
Both raise growth hormone through the ghrelin receptor, but ipamorelin is injected 2–3 times a day, and MK-677 is a small molecule (not a peptide) taken by mouth once a day. MK-677’s effect on GH and IGF-1 lasts about a day; ipamorelin’s half-life is about 2 hours. Commonly reported: strong hunger on MK-677, and milder hunger on ipamorelin than on GHRP-6.
Side by side
| Compared | Ipamorelin | MK-677 |
|---|---|---|
| Category | Growth hormone | Growth hormone |
| Also known as | IPAM | Ibutamoren, Nutrobal, MK677, Ibutamoren Mesylate |
| What it is | Considered the 'cleanest' growth hormone stimulator: in animal studies it triggers the pituitary to release GH without raising cortisol, a side effect common with other GH peptides. | Not actually a peptide — it's a small molecule you take orally that mimics ghrelin to stimulate GH release. |
| How it works | Selective growth hormone secretagogue and ghrelin receptor agonist. In animal studies it released GH without raising cortisol or ACTH, and users report milder hunger than with GHRP-6. Considered one of the cleanest GH pulses available. | Orally active ghrelin receptor agonist and GH secretagogue. Stimulates GH and IGF-1 with little short-term effect on cortisol (a small rise over a year). Its long-lasting effect on GH and IGF-1 allows once-daily oral dosing. Significantly increases appetite and promotes deep sleep. MK-677 is a small molecule GH secretagogue, not a peptide — included because it is extremely commonly tracked alongside peptide GH protocols. |
| Commonly reported | Deeper sleep and vivid dreams first, then better recovery, skin quality and gradual body-composition changes, with milder hunger than GHRP-6. Its human data are a small GH study and phase 2 trials in surgical patients; it was never approved. | Strong hunger, especially in the first weeks; water retention with puffy hands and feet or tingling hands; and deeper sleep with vivid dreams, sometimes with morning grogginess. Once-daily dosing boosts natural GH pulses and keeps IGF-1 elevated. |
| Studied range | Research range: 200–300 mcg, starting dose 200 mcg. Studied in research — not a recommendation. | Research range: 10–25 mg, starting dose 10 mg. Studied in research — not a recommendation. |
| How often | 2–3x daily, best fasted or before bed | Daily, before bed |
| Half-life | ~2 hours (measured in healthy men, given IV) | ~24 hours (community estimate; no half-life has been published for people: in dogs it was 4–6 hours, and its effect on GH and IGF-1 lasts about a day) |
| Route | SubQ injection, IM injection | Oral |
| Typical run | Commonly 8–12 weeks on, 4 weeks off to avoid receptor desensitisation. Some run longer with breaks. | Continuous use common (oral convenience). Some cycle 3 months on / 1 month off. Long-term safety data limited. |
| Evidence | Moderate: animal studies + some human data | Moderate: animal studies + some human data |
| Common side effects | Headache, flushing, nausea, water retention, numbness/tingling | Increased appetite, water retention, lethargy, elevated fasting glucose, vivid dreams, carpal tunnel symptoms |
- Category
- IpamorelinGrowth hormone
- MK-677Growth hormone
- Also known as
- IpamorelinIPAM
- MK-677Ibutamoren, Nutrobal, MK677, Ibutamoren Mesylate
- What it is
- IpamorelinConsidered the 'cleanest' growth hormone stimulator: in animal studies it triggers the pituitary to release GH without raising cortisol, a side effect common with other GH peptides.
- MK-677Not actually a peptide — it's a small molecule you take orally that mimics ghrelin to stimulate GH release.
- How it works
- IpamorelinSelective growth hormone secretagogue and ghrelin receptor agonist. In animal studies it released GH without raising cortisol or ACTH, and users report milder hunger than with GHRP-6. Considered one of the cleanest GH pulses available.
- MK-677Orally active ghrelin receptor agonist and GH secretagogue. Stimulates GH and IGF-1 with little short-term effect on cortisol (a small rise over a year). Its long-lasting effect on GH and IGF-1 allows once-daily oral dosing. Significantly increases appetite and promotes deep sleep. MK-677 is a small molecule GH secretagogue, not a peptide — included because it is extremely commonly tracked alongside peptide GH protocols.
- Commonly reported
- IpamorelinDeeper sleep and vivid dreams first, then better recovery, skin quality and gradual body-composition changes, with milder hunger than GHRP-6. Its human data are a small GH study and phase 2 trials in surgical patients; it was never approved.
- MK-677Strong hunger, especially in the first weeks; water retention with puffy hands and feet or tingling hands; and deeper sleep with vivid dreams, sometimes with morning grogginess. Once-daily dosing boosts natural GH pulses and keeps IGF-1 elevated.
- Studied range
- IpamorelinResearch range: 200–300 mcg, starting dose 200 mcg. Studied in research — not a recommendation.
- MK-677Research range: 10–25 mg, starting dose 10 mg. Studied in research — not a recommendation.
- How often
- Ipamorelin2–3x daily, best fasted or before bed
- MK-677Daily, before bed
- Half-life
- Ipamorelin~2 hours (measured in healthy men, given IV)
- MK-677~24 hours (community estimate; no half-life has been published for people: in dogs it was 4–6 hours, and its effect on GH and IGF-1 lasts about a day)
- Route
- IpamorelinSubQ injection, IM injection
- MK-677Oral
- Typical run
- IpamorelinCommonly 8–12 weeks on, 4 weeks off to avoid receptor desensitisation. Some run longer with breaks.
- MK-677Continuous use common (oral convenience). Some cycle 3 months on / 1 month off. Long-term safety data limited.
- Evidence
- IpamorelinModerate: animal studies + some human data
- MK-677Moderate: animal studies + some human data
- Common side effects
- IpamorelinHeadache, flushing, nausea, water retention, numbness/tingling
- MK-677Increased appetite, water retention, lethargy, elevated fasting glucose, vivid dreams, carpal tunnel symptoms
Typical run: Community practice — opinions vary. Not a clinical recommendation.
Week by week
Each entry’s cards by day window, as the compound pages show them. Day 1 is the day you start it.
Ipamorelin
- Day 1–14 Sleep is deepening
- Day 14–28 Recovery is noticeably faster
- Day 28–56 Body composition shifts showing up
- Day 56–84 Cycle-end + planned break
MK-677
- Day 1–14 Hunger up, sleep deeper, water on
- Day 14–56 Lean mass is climbing
- Day 56–90 Check your labs — glucose is the watch item
Together or one or the other
Ipamorelin and MK-677 are a common stack: MK-677 lists ipamorelin among its common stacks.
Community · MK-677
Orals + injectables for broader GH coverage
Common stack: MK-677's once-daily dose keeps IGF-1 up and lifts GH pulses and troughs, while injected CJC-1295 adds GHRH-receptor stimulation on top. Ipamorelin works on the same receptor as MK-677, so that pairing overlaps. Commonly reported: the side effects add up, with more water retention and hunger than either alone.
Questions people ask
How long do ipamorelin and MK-677 last?
The half-life of ipamorelin is ~2 hours (measured in healthy men, given IV). The half-life of MK-677 is ~24 hours (community estimate; no half-life has been published for people: in dogs it was 4–6 hours, and its effect on GH and IGF-1 lasts about a day).
How often are ipamorelin and MK-677 taken?
Ipamorelin: 2–3x daily, best fasted or before bed. Routes: SubQ injection, IM injection. MK-677: daily, before bed. Route: Oral.
How are ipamorelin and MK-677 dosed in research?
The research range for ipamorelin is 200–300 mcg, with a 200 mcg starting dose. The research range for MK-677 is 10–25 mg, with a 10 mg starting dose. Studied in research — not a recommendation.
What are the common side effects of ipamorelin and MK-677?
For ipamorelin, the library lists: headache, flushing, nausea, water retention, numbness/tingling. For MK-677: increased appetite, water retention, lethargy, elevated fasting glucose, vivid dreams, carpal tunnel symptoms.
Are ipamorelin and MK-677 taken together?
Ipamorelin and MK-677 are a common stack: MK-677 lists ipamorelin among its common stacks. Common stack: MK-677's once-daily dose keeps IGF-1 up and lifts GH pulses and troughs, while injected CJC-1295 adds GHRH-receptor stimulation on top. Ipamorelin works on the same receptor as MK-677, so that pairing overlaps. Commonly reported: the side effects add up, with more water retention and hunger than either alone.
Each one in full
PepVault for iPhone
Track either one in PepVault
Log every dose of ipamorelin or MK-677, with reminders on your schedule. 7 days free on the yearly plan for new subscribers.
