# Regimen and cycles

Source: https://onco.cc/terms/chemotherapy-regimen/  
OnCo record `chemotherapy-regimen` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A regimen is a named recipe of drugs, doses and timing; a cycle is one round of it, usually two to four weeks, giving normal tissues time to recover before the next. 'Six cycles of FOLFOX' means six repeats of that recipe.

## Summary

Regimens are named by acronym (R-CHOP, FOLFOX, AC-T, VRd, 7+3) or trial (the KEYNOTE-522 regimen), specify each drug's dose per body surface area or weight and its schedule (day 1, days 1-14), and are given for a defined number of cycles or until progression or intolerance. Cycle length is set by marrow recovery, so dose-dense schedules need growth factor support. Modern regimens increasingly mix chemotherapy with antibodies and immunotherapy, and fixed-duration versus continuous designs are a live question in many diseases.

## Fields

- Kind: Term
- Last checked: 2026-09-09
- Also known as: regimen; regimens; chemotherapy regimen; treatment regimen; cycles; chemotherapy cycles; cycles of chemotherapy; 21-day cycle; 28-day cycle; every 3 weeks; q3w; q2w; q4w; day 1; days 1-14; ×6 cycles; × 6; chemotherapy cycle

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Chemotherapy_regimen
- Wikipedia: https://en.wikipedia.org/wiki/Chemotherapy_regimen

## Connected records

- terms: [Dose reduction, interruption and discontinuation](https://onco.cc/terms/dose-modification/), [Dose-dense and metronomic chemotherapy](https://onco.cc/terms/dose-dense-chemotherapy/), [Doublet, triplet and quadruplet regimens](https://onco.cc/terms/doublet-triplet/), [FOLFOX, FOLFIRI, FOLFIRINOX and CAPOX](https://onco.cc/terms/folfox-family/), [R-CHOP (lymphoma chemoimmunotherapy)](https://onco.cc/terms/r-chop/)
- fronts: [Chemotherapy](https://onco.cc/fronts/chemotherapy/)

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