MK-677 side effects on TikTok: what the studies actually say

What did @antrasena7 actually say?

The transcript from this video is largely incoherent, which makes direct quoting impossible for most of it. What we can work with is the written caption, which claims MK-677's two most common side effects are increased appetite and water retention. The creator attributes the hunger effect to ghrelin and the water retention to elevated IGF-1, and specifies that the swelling is "bukan lemak, tapi cairan" (not fat, but fluid). These are the actual checkable claims here. The verbal content of the video, based on the transcript provided, does not yield coherent statements worth analyzing.

So we are fact-checking the caption, not the spoken content. That is worth being transparent about up front.

Does the science back this up?

On the hunger side, yes, the mechanism is real. MK-677 is a ghrelin mimetic, meaning it binds to the ghrelin receptor (GHSR-1a) and stimulates growth hormone secretion. Ghrelin is well-established as an orexigenic hormone. Increased appetite is one of the most consistently reported effects in the clinical literature. Chapman et al. (1996, Journal of Clinical Endocrinology and Metabolism) documented significant increases in appetite in their early dose-escalation work with MK-677 in healthy adults.

Water retention is also real and mechanistically plausible. IGF-1 promotes sodium and water reabsorption in the kidneys. When MK-677 raises GH and downstream IGF-1, mild edema, particularly in the extremities, is a predictable result. Svensson et al. (1998, Journal of Clinical Endocrinology and Metabolism) reported edema as a dose-dependent side effect in studies with MK-677 in adults with GH deficiency. The "not fat, but fluid" distinction is technically correct, though it is worth noting that distinguishing the two subjectively is harder than the caption implies.

What did they get wrong (or right)?

Credit where it is due: the two side effects listed are genuinely the most commonly reported in trials, and the mechanistic explanations are directionally accurate. Most content about MK-677 on social media either ignores side effects entirely or dramatically overstates benefits, so naming the downsides is a reasonable move.

What is missing, and this is a significant omission, is any mention of the more serious risks. MK-677 has been shown to worsen insulin sensitivity. Nass et al. (2008, Annals of Internal Medicine) found that two years of MK-677 use in older adults significantly increased fasting glucose and HbA1c levels. For anyone with prediabetes or metabolic syndrome, this is not a footnote. It is arguably the most clinically relevant risk.

The caption also frames these effects as manageable inconveniences without noting that MK-677 is not approved by any major regulatory body for human use outside of clinical trials. Presenting it as a clean compound with two mild, easily explained side effects is, at best, incomplete framing.

What should you actually know?

MK-677 has real pharmacological activity. It raises GH and IGF-1 measurably, which is why it has attracted research attention in sarcopenia, GH deficiency, and catabolic conditions. But "pharmacologically active" also means it carries real risks that go beyond bloating and hunger.

The insulin resistance signal from the literature is not subtle. The two-year RCT by Nass et al. is the longest controlled human trial available, and the glucose findings should be part of any honest conversation about this compound. People with family histories of diabetes, anyone already managing blood sugar, or individuals who are overweight are in a different risk category than a lean, healthy young adult.

Water retention may also be a proxy for IGF-1 levels running higher than intended. Without lab monitoring, users have no way to know where their IGF-1 actually lands. Chronically elevated IGF-1 has associations with certain cancer risks in epidemiological literature, though causality from supplementation specifically has not been established.

MK-677 is also not a legally approved therapeutic in most countries. Sourcing, purity, and dosing accuracy outside of a supervised clinical context are genuine variables that no amount of TikTok education resolves.