Research

Hormonal

Second-generation oral contraceptive pill phase (active vs. inactive) does not influence muscle protein synthesis or myofibrillar proteolysis at rest or in response to resistance exercise.

If you take second-generation birth control pills, you can train for muscle growth without worrying about your pill cycle. Your muscles build and break down protein at the same rate whether you are on the active pills or the placebo week. Focus on your training and nutrition; the pill phase does not matter for your results.

GoodRefutesHIGH confidence
Our data show that OCP phase neither influences skeletal muscle protein turnover in females and nor supports a marked procatabolic or anabolic effect.
Lauren M. Colenso‐Semple et al. · Journal of Applied Physiology · 2025

Why this rating

Randomized crossover design with stable isotope tracers and muscle biopsies, though limited by small sample size (n=12) and short duration (6 days).

Source

Oral contraceptive pill phase does not influence muscle protein synthesis or myofibrillar proteolysis at rest or in response to resistance exercise

Lauren M. Colenso‐Semple et al. · Journal of Applied Physiology · 2025

DOI 10.1152/japplphysiol.00035.2025

crossover · n=12Cited 7×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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