Downregulation

Also known as “desensitization”

Last updated August 2026

When repeated stimulation makes cells reduce their receptors or responsiveness, blunting a peptide’s effect over time. A reason cycling and dose breaks are discussed.

Downregulation is the biological reason a steady, unbroken dose can seem to lose effect over weeks: cells respond by trimming their receptors or dialing down sensitivity. It is the mechanism most often cited to justify cycling or scheduled breaks, though how quickly it sets in varies by peptide and target. It is a slower process than tachyphylaxis, which describes a much more rapid drop in response.

Educational reference only — not medical advice. Always follow the guidance of a qualified healthcare professional.