Do cortisol levels change throughout the menstrual cycle?
Answer: It depends.
Stress is a common complaint among anyone over the age of 12. I’m convinced puberty brings about the existence of stress, and it probably has something to do with the hormones it hurls at us. There have been anecdotes swapped among friends that periods can affect your stress levels too. I don’t find it unbelievable, but do our stress levels really change depending on which part of the menstrual cycle one is in or is the stress from the cyclic show of blood itself?
The difficult thing about stress, or rather, one of the several difficult things about it, is that it could be complicated to measure in an objective way. Self-reports give us snapshots of stress data, but may be heavily biased by the participant’s beliefs. Another way to approximate stress in a slightly more objective way is through the levels of cortisol in the body. (I say slightly since cortisol levels could be affected by our interpretations of threats and thought patterns, which could make them highly variable and vulnerable to changes in mood or situational factors) Cortisol is a hormone regarded as the main stress hormone and influences many processes in the body, including metabolism and immunity. Researchers can measure cortisol levels in blood, urine, or saliva, with saliva being the simplest collection method.
Through the measurement of cortisol levels, some researchers have found that cortisol levels do change across the menstrual cycle, with higher cortisol levels in the follicular phase compared to the luteal phase (Hamidovic et al., 2020; Kulzhanova et al., 2023; Prado et al., 2025). Cortisol levels after exercise have also been found to be higher in the follicular phase, while cognitive function (our thinking and learning) fortunately was found to remain the same throughout the cycle (Mirzaei Khalil Abadi et al., 2024). An interesting deviation from this trend comes from another research team finding that the responses to stress were higher in the luteal phase (Montero-López et al., 2018), so further research is required for any conclusive statement to be made (as usual).
Wait, what is the follicular phase again? Remember that the follicular phase is the first half of the menstrual cycle from the first day of menses (period) to ovulation (when the egg is released). The luteal phase is the second half after ovulation until menstruation occurs again, restarting the menstrual cycle. For more information, this text outlines each phase in detail.
For an even further deviation from the research above, we can look to researchers who find that there are no significant changes in cortisol levels throughout the menstrual cycle (Kanaley et al., 1992; Kayacan et al., 2021; Walker et al., 2025).
So, it really does depend… These inconsistencies could be due to differences in cortisol collection methods. Though elevated cortisol levels may indicate stress, it could also mean the body is preparing to adapt to changing hormone levels, which in turn could affect cortisol and may even differentiate responses between those who experience premenstrual syndrome (PMS) and those who do not. Stress could also be measured with something other than physiological cortisol levels, such as subjective stress reports. A research team studied the relationship between subjective and physiological stress responses across the menstrual cycle and found subjective stress reports increased with increasing cortisol levels, but only in the luteal phase – in the follicular phase, increasing cortisol corresponded to decreasing subjective stress responses (Duchesne & Pruessner, 2013).
One may not be able to conclusively say that cortisol levels vary in a regular way across the menstrual cycle, but I do think it makes sense to say that cortisol levels change throughout the cycle simply because stress exists. There are many reasons for stress, and not having clear answers is one of them.
REMEMBER: Please continue to be critical of the news, articles, and information you review. This post and site are for information purposes only. They do not provide medical advice, diagnosis, treatment or care. Please contact a qualified healthcare provider if you seek care. Thank you.
FURTHER READING: The following are the resources linked above, in order of appearance in the text:
Interactions of momentary thought content and subjective stress predict cortisol fluctuations in a daily life experience sampling study https://pmc.ncbi.nlm.nih.gov/articles/PMC6193976/
Physiology, Cortisol https://www.ncbi.nlm.nih.gov/books/NBK538239/
Cortisol Test https://my.clevelandclinic.org/health/diagnostics/22417-cortisol-test
Higher Circulating Cortisol in the Follicular vs. Luteal Phase of the Menstrual Cycle: A Meta-Analysis https://pmc.ncbi.nlm.nih.gov/articles/PMC7280552/
The cortisol levels in the follicular and luteal phases of the healthy menstruating women: a meta-analysis https://pubmed.ncbi.nlm.nih.gov/37750645/
Effects of the Menstrual Cycle Phase on Cortisol Responses to Maximum Exercise in Women With and Without Premenstrual Syndrome https://pmc.ncbi.nlm.nih.gov/articles/PMC11970578/
Effects of menstrual cycle on cognitive function, cortisol, and metabolism after a single session of aerobic exercise https://pmc.ncbi.nlm.nih.gov/articles/PMC11521275/
The relationship between the menstrual cycle and cortisol secretion: Daily and stress-invoked cortisol patterns https://pubmed.ncbi.nlm.nih.gov/29605399/
The Normal Menstrual Cycle and the Control of Ovulation https://www.ncbi.nlm.nih.gov/books/NBK279054/
Cortisol levels during prolonged exercise: the influence of menstrual phase and menstrual status https://pubmed.ncbi.nlm.nih.gov/1521947/
Cortisol Awakening Response and Heart Rate Variability in the Menstrual Cycle of Sportswomen https://pubmed.ncbi.nlm.nih.gov/32853053/
Impact of the menstrual cycle phases and time of day on markers of stress: salivary α-amylase and secretory immunoglobulin A https://pubmed.ncbi.nlm.nih.gov/39757714/
Association between subjective and cortisol stress response depends on the menstrual cycle phase https://pubmed.ncbi.nlm.nih.gov/24055042/












