GymTok peptide claims vs. what research actually shows

What did @doriancolom actually say?

The creator made a handful of claims worth examining. He said MK-677 is not a SARM, that it works by stimulating the pituitary to release more growth hormone and IGF-1, that it makes you intensely hungry, and that it lowers insulin sensitivity. He also said it causes water retention in some users and that he would only recommend it to people who genuinely struggle to eat enough. He framed it as a modest compound, not a transformation drug.

That framing is actually more responsible than most MK-677 content on GymTok, which tends to oversell it. He was direct about the downsides and did not claim it builds muscle on its own. A few of his mechanistic explanations need some correction, though.

Does the science back this up?

Mostly yes, with one notable error in how he explained the hunger mechanism. MK-677 is a ghrelin mimetic and a growth hormone secretagogue, not a direct growth hormone or IGF-1 analog. It binds to ghrelin receptors (GHSR-1a) and triggers the pituitary to pulse growth hormone, which then drives IGF-1 production in the liver. That part he got right.

The hunger claim is well-supported. Ghrelin is sometimes called the "hunger hormone," and MK-677's agonism at ghrelin receptors does produce significant appetite stimulation. A randomized controlled trial by Svensson et al. (2000, Journal of Clinical Endocrinology and Metabolism) confirmed that MK-677 administration increased appetite and food intake in healthy adults. That tracks with what the creator described.

On insulin sensitivity: the evidence is real. Murphy et al. (1998, Journal of Clinical Endocrinology and Metabolism) found that MK-677 increased fasting blood glucose and reduced insulin sensitivity in older adults after two months of use. This is a legitimate metabolic concern, not a minor footnote.

What did they get wrong (or right)?

He said MK-677 "increases the amount of growling in your body," which appears to be a mangled attempt at saying it increases ghrelin. To be precise: MK-677 does not necessarily increase circulating ghrelin levels. It mimics ghrelin by activating the same receptor. That is a mechanistic difference that matters if you are trying to understand what the compound actually does.

He also got the insulin sensitivity direction slightly confused mid-video. He said it "lowers your insulin sensitivity" and separately said "it could raise your blood sugar because it lowers your insulin sensitivity." Both of those statements point in the same direction, so the logic is internally consistent, but the way he worded it made it sound circular. The core warning is accurate: reduced insulin sensitivity can impair muscle nutrient uptake and raises metabolic risk, particularly for people with pre-diabetes or a family history of type 2 diabetes.

What he got right: the classification correction. MK-677 is not a SARM. It is not a selective androgen receptor modulator. Calling it a growth hormone secretagogue is accurate. That distinction matters legally and physiologically.

What should you actually know?

MK-677 is an investigational compound. It has never been approved by the FDA for any indication. It is not a supplement, despite being sold that way in many online markets. Research by Nass et al. (2008, Journal of Clinical Endocrinology and Metabolism) showed it increased IGF-1 and growth hormone in older adults, but the same study noted elevated fasting glucose as a consistent side effect across the study population.

The water retention the creator describes is real and tied to increased aldosterone activity secondary to GH elevation. Some users retain several pounds of fluid, which can obscure body composition changes and affect blood pressure.

The creator's advice to only use it during a caloric surplus is pragmatically reasonable given the appetite stimulation, but it is not a clinical recommendation. Anyone considering MK-677 should have baseline bloodwork including fasting glucose, HbA1c, and IGF-1 levels, and should be monitored by a licensed clinician. This is not a compound to experiment with casually based on a TikTok video, including this one.