Endurance peptides FAQ

Pause dose escalation at 3mg weekly for an additional four weeks. The transient glucose elevation reflects hepatic glucose output increasing before adipose lipolysis compensates. If fasting glucose remains above 110mg/dL after eight weeks at 3mg, the participant likely has underlying insulin resistance that requires metabolic correction before introducing glucagon agonism. The alternative is pairing mazdutide with metformin (500–1,000mg daily), which suppresses hepatic gluconeogenesis without interfering with the lipolytic or appetite-suppressing effects. This combination is standard in clinical settings and doesn't confound endurance research outcomes, but adds a pharmacological variable to track.

Reduce dose to 12.5mg daily and reassess after two weeks. The ghrelin receptor response is dose-dependent, and lower doses often preserve IGF-1 elevation while minimising aldosterone-mediated sodium retention. If water retention persists, consider administering the dose every other day rather than daily; the 24-hour half-life maintains sufficient plasma levels for GH pulsatility without continuous receptor saturation. Combining MK-677 with a potassium-sparing diuretic is not recommended in research settings due to confounding electrolyte variables, but ensuring adequate hydration (3–4L daily) and moderating sodium intake to <2,300mg reduces subcutaneous water accumulation by 40–60% in most cases.

Verify dosing reached the EC50 threshold. Phase 2a data used 50mg daily subcutaneous administration, which corresponds to plasma levels of approximately 180ng/mL at steady state. Doses below 35mg often fail to activate ERRα sufficiently. Confirm peptide storage remained at 2–8°C throughout handling; temperature excursions above 8°C denature the tertiary structure and render the compound inactive. If both factors are controlled and no effect is observed, consider that the study population may have mitochondrial dysfunction severe enough to impair transcriptional machinery downstream of ERRα. This occurs in advanced mitochondrial myopathies where PGC-1α is present but non-responsive.

Cease EPO-related peptide administration immediately and consider phlebotomy (therapeutic blood draw) if hematocrit exceeds 54%. Blood viscosity increases exponentially above 52%, elevating stroke and thrombosis risk far beyond any performance advantage. Resume the protocol at 50% of the original dose only after hematocrit stabilises below 50% for at least two weeks. Endurance performance peaks at hematocrit values between 48–52%. Higher values impair capillary perfusion and negate oxygen transport gains.

Reduce peptide doses by 30–50% if training volume decreases for more than one week. Growth hormone and EPO-stimulating peptides drive adaptations in response to training stress. Without sufficient stimulus, continued high doses increase side effect risk (edema, insulin resistance, elevated hematocrit) without meaningful adaptation. Peptide protocols amplify training response; they don't replace training stimulus. Restore full dosing only when training load returns to baseline.

Skip growth hormone peptides and prioritise EPO-stimulating or PPAR-delta compounds instead. Individuals with IGF-1 levels in the upper quartile of the reference range (>250 ng/mL in adults) will see minimal additional mitochondrial adaptation from GH secretagogues because hepatic IGF-1 production is already near maximal output. The dose required to push IGF-1 meaningfully higher introduces unnecessary risk of insulin resistance and joint pain without proportional endurance benefit. Verify baseline IGF-1 with serum testing before initiating any GH-based protocol.