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Peptide Cycling: When Breaks Matter and When They Don't

Receptor desensitization, IGF-1 drift, and how cycling logic differs between GH secretagogues, repair peptides, and GLP-1 agonists.

Why cycling exists

Continuous ghrelin-receptor stimulation downregulates receptor density, so GH secretagogues lose effect over months. Typical protocols run 8–12 weeks on with 4 weeks off.

Repair peptides are cycled for a different reason: they are used for a defined injury window, then stopped once function returns.

GLP-1 agonists are not cycled

Incretin therapies for obesity are maintenance treatments. Trial data consistently show weight regain after discontinuation, so stopping is a clinical decision rather than a protocol reset.

What to monitor across a cycle

For GH-axis peptides: IGF-1, fasting glucose, HbA1c, and blood pressure at baseline, mid-cycle, and end.

For metabolic peptides: weight trend, waist circumference, lipid panel, and any GI symptom burden.

Track subjective markers too — sleep, energy, mood — since these often shift before lab values do.