It depends on the case; there is no single guideline.
Effect by goal · level of evidence
Physical performance in women
no clear effectModeratemeta-analysis (AAA)
Meta-analysis: the menstrual cycle phase has, on average, a small and inconsistent effect on physical performance (a slight tendency toward worse performance in the early follicular phase). It is better to individualize than to apply a fixed rule.
Physical performance in women — no clear effect (Moderate, meta-analysis). Meta-analysis: the menstrual cycle phase has, on average, a small and inconsistent effect on physical performance (a slight tendency to be worse in the early follicular phase). It is better to individualize than to apply a fixed rule. 32661839
Information, not medical advice. Prescription drugs require a doctor.
Information, not medical advice. Scientific evidence reflects the quality of the studies.