MK-677 vs Sermorelin

The Dose Guy’s verdict

Oct 27, 2026
8 sources

Pick by the diet you are on. On a bulk, or if needles are a dealbreaker, MK-677: it is a pill, it raises GH and IGF-1 reliably, and it deepens sleep, but it brings a wall of hunger, water weight, and a glucose hit you have to monitor. On a cut, or if your glucose already runs high, sermorelin with ipamorelin is the gentler route. If you are willing to pin at all, though, CJC-1295 does sermorelin’s job better.

Which would I take?MK-677 on a bulk, sermorelin on a cut.

How they differ

The biggest difference is your appetite. MK-677, sold as ibutamoren, is a pill that switches on the ghrelin receptor, the hunger receptor, which also happens to fire a GH pulse; it is the same receptor ipamorelin hits, though ipamorelin is the selective one that fires the pulse without the appetite. Sermorelin is an injection of GHRH, the other signal your brain uses to ask your pituitary for growth hormone. Both are growth-hormone secretagogues, meaning your body makes the GH and the drug only asks for it. But MK-677 gives you GH and hunger from one switch, and sermorelin gives you GH and leaves your appetite alone. That one fact decides the bulk and cut split.

MK-677 is also the stronger, steadier push: one dose a day keeps IGF-1 climbing over weeks, where each sermorelin shot is a short nudge that works best with ipamorelin beside it. The costs land in different places. MK-677 changes your meals and your scale: hunger is loudest the first two to four weeks, pounds of water arrive in the first week, and fasting glucose creeps. Sermorelin changes your schedule: two or three empty-stomach pins a day, with dinner moved earlier for the pre-bed shot.

So the Reddit version of this question is really needles against side effects. If you will not inject, MK-677 is the only option on this page, and you take it with a glucose meter. If you will, sermorelin is the cleaner of the two, and CJC-1295 is cleaner still.

What the research shows

MK-677 has the deeper human record by a wide margin, and nobody has put the two in one trial:

No head-to-head trial of MK-677 against sermorelin exists, and sermorelin has no modern randomized trial in adults for body composition, recovery, or performance.as of Aug 2026

At one year in healthy older adults, fat-free mass changed by 1.1 kg on MK-677 versus a loss of 0.5 kg on placebo, but the extra fat-free mass did not improve strength or function.Annals 2008 · RCT · 2 yr · n=65

In eight young adults, MK-677 25 mg increased stage IV deep sleep by about 50% and REM sleep by more than 20% versus placebo after seven days.Neuroendocrinology 1997 · crossover

In healthy older adults on MK-677 25 mg, fasting glucose rose from 5.4 to 6.8 mmol/L after four weeks.JCEM 1996 · dose-ranging · n=32

In testosterone-treated men, sermorelin with GHRP-2 and GHRP-6 at 100 mcg each, three times daily, raised IGF-1 from 159.5 to 239.0 ng/mL over a mean 134 days. There is no way to isolate sermorelin’s share.AJMH 2017 · retrospective · n=14

Different trials, different people, decades apart. MK-677’s receipts show a real GH effect and a real glucose cost; sermorelin’s show that it moves IGF-1 in combination and little else.

How people run them

MK-677 starts at 10–15 mg, swallowed before bed so you sleep through the worst of the hunger and the GH pulse lines up with your natural overnight surge. The trials used 25 mg daily; treat that as a ceiling, not a goal, and holding a low dose that works is winning. Check fasting glucose before you start and every few weeks after, and judge progress by the mirror, not the scale, because the water hides everything. Sermorelin runs at 200–300 mcg sub-q, two or three times a day on an empty stomach, pre-bed as the anchor, with ipamorelin in the same syringe.

Switching from MK-677 to sermorelin, stop the pill and start sermorelin the next night; no washout needed. Over the next week or two the hunger fades and the water leaves, so the scale drops. That is fluid, not lost muscle. Recheck your glucose a few weeks later. Going the other way, start MK-677 at 10 mg the night after your last sermorelin shot and give the hunger a few weeks to settle before you judge it.

They can run together on paper, since MK-677 sits on the GHRP side and sermorelin on the GHRH side, and some people do on a bulk. You get MK-677’s hunger and glucose on top of the pins. If you are pinning sermorelin anyway, ipamorelin is the cleaner partner, and there is no point running MK-677 with ipamorelin, because they share a receptor.

MK-67710–15 mg/dayOral, pre-bed; 25 mg is the trial dose and a ceiling, not a goal.

Sermorelin200–300 mcg, 2–3x/daySub-q, empty stomach, pre-bed anchor, paired with ipamorelin.

MK to serm200–300 mcg, next nightThe hunger and water fade over a couple of weeks; recheck glucose.

Serm to MK10 mg, next nightStart low and let the appetite settle before you judge it.

TogetherMK-677 + sermorelinA bulk-only stack; ipamorelin is the cleaner partner if you pin anyway.

Side effects, side by side

MK-677’s sides are louder and better documented; sermorelin’s are small and short:

commonAppetite surge on MK-677, strongest in the first weeks, easing over months but not gone. Sermorelin leaves your appetite alone.

commonWater retention on MK-677, sometimes pounds in the first week, with puffy hands, feet, or face. It is fluid, not tissue, and usually settles with time or a lower dose.

commonFlushing right after a sermorelin shot, brief and harmless, plus injection-site irritation from pinning two or three times a day.

monitorFasting glucose rises and insulin sensitivity worsens on MK-677, documented across its trials. Check fasting glucose before you start and every few weeks after. Sermorelin carries a smaller version of the same GH-axis signal.

monitorOne case report of liver enzymes rising after two months of MK-677, back to normal after stopping. Get a baseline liver panel.

unknownSermorelin has no modern long-term adult safety study; its reassuring history is in children.