PeptidePros

Compare · Head-to-head

MK-677 vs MOTS-c.

Evidence, risk, regulatory flags, cost, and vendor coverage compared side by side. We don’t sell peptides — we help you choose between them.

Which should you research first?

Start with MK-677, then use the table to confirm fit.

MK-677 is the cleaner first read based on the current evidence, risk, and regulatory data stored for this pair. The right answer can still change if your goal, sport testing status, vendor constraints, or monitoring tolerance makes the other option a better fit.

Comparison next step

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01· Subject

MK-677

Oral ghrelin-receptor agonist used as a GH secretagogue in research and bodybuilding markets.

Tier Cmed-high risk

02· Subject

MOTS-c

Mitochondrial-derived peptide studied in mouse models for metabolic homeostasis and insulin sensitivity.

Tier Chigh risk

01 · At a glance

Decision factorMK-677MOTS-c
Primary fitmuscle growth & strength and longevity & anti-aging comparisonsfat loss & metabolism and longevity & anti-aging comparisons
EvidenceTier CTier C
Riskmed-highhigh
Experience leveladvancedadvanced
Budget tiermidpremium
Administration routeoralsubcutaneous

02 · Use case & timing

Decision factorMK-677MOTS-c
Goal fitMuscle Growth & Strength, Longevity & Anti-Aging, GH Axis OptimizationFat Loss & Metabolism, Longevity & Anti-Aging
What users compare it forIncreased GH/IGF-1 signaling, appetite rise, and potential lean-mass increase in some human studies.Preclinical: improved insulin sensitivity, metabolic regulation, exercise performance in mice.
Onset timelineGH rises acutely; IGF-1 and body-composition effects are tracked over weeks to months.Metabolic endpoints assessed over days to weeks in mice; exercise performance improvements after ~10 days.
Main tradeoffEvidence and product availability can still be uneven, so documentation matters more than hype.Potential upside comes with much more safety and screening caution than lower-risk alternatives.

03 · Safety & restrictions

Decision factorMK-677MOTS-c
Adverse effectsEdema, increased appetite, insulin resistance, elevated fasting glucose, joint discomfort, and possible cardiovascular safety concerns.FDA: no identified human exposure data; significant immunogenicity/characterization risks.
ContraindicationsUse caution in diabetes, insulin resistance, edema-prone states, heart failure risk, and active malignancy.No human data.
Interaction notesCombining with other GH-axis compounds increases endocrine complexity and may worsen glucose control.Unknown.
Regulatory statusNot approvedNot approved
FDA flagFDA compounding cautionFDA compounding caution
WADA statusWADA S2Status unclear

04 · Age & monitoring

Decision factorMK-677MOTS-c
Supported age ranges25-34, 35-44, 45-54No age guidance yet
Life-stage noteMost often discussed for younger and midlife adults, but metabolic and fluid-retention risks narrow the fit quickly with age.Not yet documented
Monitoring burdenhighNot specified
Follow-up cadenceMore frequent early follow-up, then reassessment every few months if continued.Not yet documented

05 · Cost & sourcing

Decision factorMK-677MOTS-c
Typical cycle costNo reliable estimate yet€33.02
Estimated monthly costNo reliable estimate yet€33.02
Cost confidenceNo estimateHigh confidence

06 · Before you buy

Decision factorMK-677MOTS-c
Tracked vendor listings0 listings3 listings
Sourcing noteNo tracked product page yet, so sourcing takes more manual review.Product format varies by listing, so double-check route, concentration, and presentation.
Stack-friendly?Usually stack-friendlyUsually stack-friendly

Sources and review notes

  1. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks - U.S. Food and Drug Administration - accessed 2026-05-15

    Used for FDA compounding-risk context and peptide safety flags.

  2. The Prohibited List - World Anti-Doping Agency - accessed 2026-05-15

    Used for athlete-facing WADA risk and peptide-class restrictions.

  3. Peptide therapeutics: current status and future directions - PubMed / Nature Reviews Drug Discovery - accessed 2026-05-15

    Used for broad peptide-therapeutics background and evidence framing.

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