Individual differences in self-reported difficulty sleeping across the menstrual cycle

Menstrual Cycle Variations in Wearable-Detected Finger Temperature and Heart Rate, But Not in Sleep Metrics, in Young and Midlife Individuals

Most studies about the menstrual cycle are laboratory-based, in small samples, with infrequent sampling, and limited to young individuals. Here, we use wearable and diary-based data to investigate menstrual phase and age effects on finger temperature, sleep, heart rate (HR), physical activity, physical symptoms, and mood. A total of 116 healthy females, without menstrual disorders, were enrolled: 67 young (18-35 years, reproductive stage) and 53 midlife (42-55 years, late reproductive to menopause transition). Over one menstrual cycle, participants wore Oura ring Gen2 to detect finger temperature, HR, heart rate variability (root mean square of successive differences between normal heartbeats [RMSSD]), steps, and sleep. They used luteinizing hormone (LH) kits and daily rated sleep, mood, and physical symptoms. A cosinor rhythm analysis was applied to detect menstrual oscillations in temperature. The effect of menstrual cycle phase and group on all other variables was assessed using hierarchical linear models. Finger temperature followed an oscillatory trend indicative of ovulatory cycles in 96 participants. In the midlife group, the temperature rhythm's mesor was higher, but period, amplitude, and number of days between menses and acrophase were similar in both groups. In those with oscillatory temperatures, HR was lowest during menses in both groups. In the young group only, RMSSD was lower in the late-luteal phase than during menses. Overall, RMSSD was lower, and number of daily steps was higher, in the midlife group. No significant menstrual cycle changes were detected in wearable-derived or self-reported measures of sleep efficiency, duration, wake-after-sleep onset, sleep onset latency, or sleep quality. Mood positivity was higher around ovulation, and physical symptoms manifested during menses. Temperature and HR changed across the menstrual cycle; however, sleep measures remained stable in these healthy young and midlife individuals. Further work should investigate over longer periods whether individual- or cluster-specific sleep changes exist, and if a buffering mechanism protects sleep from physiological changes across the menstrual cycle.

Early Life Trauma, Emotion Dysregulation and Hormonal Sensitivity Across Female Reproductive Life Events

PURPOSE OF REVIEW

To explore the relationship between early life trauma, hormonal sensitivity, and psychiatric disorders across female-reproductive life events, with a focus on the neurobiological mechanisms.

RECENT FINDINGS

Childhood trauma significantly increases the risk of subsequent mood disorders during periods of intense hormonal fluctuation such as premenstrual, pregnancy, postpartum, and perimenopause. Neurobiological changes resulting from early trauma influence emotion regulation, which emerges as a key predisposing, exacerbating, and perpetuating factor to hormonal sensitivity and subsequent psychiatric symptoms. We identified altered stress response and allopregnanolone imbalance, bias in cognitive processing of emotions, neuroimage correlates and sleep disturbances as potential underlying neurobiological mechanisms. This review integrates cumulative findings supporting a theoretical framework linking early life trauma to hormonal sensitivity and mood disorders. We propose that some women might be more susceptible to such hormonal fluctuations because of emotion dysregulation following significant early life trauma.

Feasibility Study on Menstrual Cycles With Fitbit Device (FEMFIT): Prospective Observational Cohort Study

BACKGROUND

Despite its importance to women's reproductive health and its impact on women's daily lives, the menstrual cycle, its regulation, and its impact on health remain poorly understood. As conventional clinical trials rely on infrequent in-person assessments, digital studies with wearable devices enable the collection of longitudinal subjective and objective measures.

OBJECTIVE

The study aims to explore the technical feasibility of collecting combined wearable and digital questionnaire data and its potential for gaining biological insights into the menstrual cycle.

METHODS

This prospective observational cohort study was conducted online over 12 weeks. A total of 42 cisgender women were recruited by their local gynecologist in Berlin, Germany, and given a Fitbit Inspire 2 device and access to a study app with digital questionnaires. Statistical analysis included descriptive statistics on user behavior and retention, as well as a comparative analysis of symptoms from the digital questionnaires with metrics from the sensor devices at different phases of the menstrual cycle.

RESULTS

The average time spent in the study was 63.3 (SD 33.0) days with 9 of the 42 individuals dropping out within 2 weeks of the start of the study. We collected partial data from 114 ovulatory cycles, encompassing 33 participants, and obtained complete data from a total of 50 cycles. Participants reported a total of 2468 symptoms in the daily questionnaires administered during the luteal phase and menses. Despite difficulties with data completeness, the combined questionnaire and sensor data collection was technically feasible and provided interesting biological insights. We observed an increased heart rate in the mid and end luteal phase compared with menses and participants with severe premenstrual syndrome walked substantially fewer steps (average daily steps 10,283, SD 6277) during the luteal phase and menses compared with participants with no or low premenstrual syndrome (mean 11,694, SD 6458).

CONCLUSIONS

We demonstrate the feasibility of using an app-based approach to collect combined wearable device and questionnaire data on menstrual cycles. Dropouts in the early weeks of the study indicated that engagement efforts would need to be improved for larger studies. Despite the challenges of collecting wearable data on consecutive days, the data collected provided valuable biological insights, suggesting that the use of questionnaires in conjunction with wearable data may provide a more complete understanding of the menstrual cycle and its impact on daily life. The biological findings should motivate further research into understanding the relationship between the menstrual cycle and objective physiological measurements from sensor devices.

The Effects of Hormonal Contraceptives on the Sleep of Women of Reproductive Age

Research about the effects of hormonal contraceptives on sleep has been performed but is subjected to important levels of methodological heterogeneity. Hormonal contraceptives impact sleep, but the direction of this association is not clear. Most studies describe a negative sleep profile among contraceptive users, including increased sleepiness, insomnia symptoms, decreased sleep efficiency, and a reduced overall sleep quality. Hormonal intrauterine contraceptives are associated with less negative effects. More research on the field, especially randomized controlled trials, is needed to increase the level and certainty of evidence about the effects of hormonal contraceptives on sleep.

The Menstrual Cycle and Sleep

Aspects of sleep change across the menstrual cycle in some women. Poorer sleep quality in the premenstrual phase and menstruation is common in women with premenstrual symptoms or painful menstrual cramps. Although objective sleep continuity remains unchanged across the regular, asymptomatic menstrual cycle, activity in the sleep electroencephalogram varies, with a prominent increase in sleep spindle activity in the postovulatory luteal phase, when progesterone is present, relative to the follicular phase. Menstrual cycle phase, reproductive stage, and menstrual-related disorders should be considered when assessing women's sleep complaints.

The Relationship Between Mood and Sleep in Different Female Reproductive States

Mood and sleep are tightly interrelated. Mood and sleep symptoms and disorders are more common in women than in men and often associated with reproductive events. This article reviews the current literature on the reciprocal relationships between mood and sleep across reproductive phases in women, such as menstrual cycle and related disorders, pregnancy, climacteric, and use of hormonal contraception and hormone replacement therapy. Mood and sleep symptoms seem to covary in relation to physiologic and pathologic reproductive conditions, although the relationship seems more clear for subjective than objective sleep.

Good sleep is a mood buffer for young women during menses

STUDY OBJECTIVES

We sought to elucidate the interaction between sleep and mood considering menstrual cycle phase (menses and non-menses portions of the cycle) in 72 healthy young women (18-33 years) with natural, regular menstrual cycles and without menstrual-associated disorders. This work fills a gap in literature of examining mood in context of sleep and menstrual cycle jointly, rather than individually.

METHODS

Daily subjective measures of sleep and mood, and date of menses were remotely, digitally collected over a 2-month period. Each morning, participants rated their sleep on the previous night, and each evening participants rated the extent of positive and negative mood for that day. Objective sleep was tracked with a wearable (ŌURA ring) during month 2 of the study. Time-lag cross-correlation and mixed linear models were used to analyze the significance and directionality of the sleep-mood relationship, and how the interaction between menstrual cycle status and sleep impacted mood levels.

RESULTS

We found that menstrual status alone did not impact mood. However, subjective sleep quality and menstrual status interacted to impact positive mood (p < .05). After a night of perceived poor sleep quality, participants reported lower positive mood during menses compared to non-menses portions of the cycle, while after a night of perceived good sleep quality participants reported equivalent levels of positive mood across the cycle.

CONCLUSIONS

We suggest that the perception of good sleep quality acts as a mood equalizer, with good sleep providing a protective buffer to positive mood across the menstrual cycle.

Menstrual cycle-driven vs noncyclical daily changes in sexual desire

BACKGROUND

Past research on the association between sexual desire and the menstrual cycle has provided inconclusive results and has not considered the potential influence of psychological and physical changes that are frequently associated with the menstrual cycle.

AIM

To test the strength of association between the menstrual cycle (and associated symptoms) and changes in sexual desire.

METHODS

Prospective daily reports across 2 full menstrual cycles (2 months) from a sample of female university students (n = 213), were analysed. Analyses tested for average effects of the menstrual cycle on sexual desire, individual differences in these effects, and cyclical and noncyclical associations between sexual desire and the 9 menstrual cycle-related changes. Note that data presented in the current article come from a larger study from which other reports have been published.

OUTCOMES

Target variables were (1) daily change in sexual desire and (2) daily reports of 5 psychological changes and 4 physical changes that are commonly associated with the menstrual cycle.

RESULTS

Results showed that when considering average effects across participants, the menstrual cycle was associated with a small midcycle increase in sexual desire. However, multilevel analyses showed large individual differences in how the menstrual cycle influences sexual desire. Specifically, some participants showed a midcycle increase, others a perimenstrual increase, and others no change across the menstrual cycle. Moreover, results demonstrated that psychological changes were more important for predicting sexual desire as compared with physical changes.

CLINICAL IMPLICATIONS

These results suggest that daily measurement of sexual desire across multiple menstrual cycles may be an important tool in the assessment of sexual desire among some females.

STRENGTHS AND LIMITATIONS

Strengths of this study are the daily assessment of sexual desire and all symptoms for 2 menstrual cycles and multilevel analyses that allow the study of individual differences. Limitations include limited measurement of sexual desire based on only 2 questions and the lack of measures of relationship status and sexual orientation.

CONCLUSION

Emphasis is placed on the need to apply more rigorous research methods and to abandon simplistic average-effects models that are based on outdated theories and stereotypes.

Interaction predictors of self-perception menstrual symptoms and influence of the menstrual cycle on physical performance of physically active women

OBJECTIVE

To analyze the physical performance, self-perception menstrual symptoms, of physically active eumenorrheic women with endogenous ovarian cycle in two phases of the menstrual cycle.

METHODS

Twenty-six women participated in the study (age 25.8 ± 3.9 years; height 1.64 ± 0.58 m; mass 64 ± 12.32 kg; menarche 11.69 ± 1.28 years). Assessments were performed in two phases of the menstrual cycle (MC), Early-Follicular Phase (FP) and Mid-Luteal Phase (LP), performance was assessed through total time to exhaustion (TTE), complete stages (CE), and final speed (FE), through a graded exercise test (GXT). Information on the participants' menstrual symptoms and their perceptions of the influence of MC on their performance were also collected. Data normality was assessed using the Shapiro-Wilk test. Paired analyses were conducted (t test or Wilcoxon) to examine the responses between the menstrual phases. The interaction analysis of symptom predictors was performed by multiple linear regression, with a significance level of p ≤ 0.05.

RESULTS

There was no significant difference in physical performance between the phases during the GXT in TTE (mean difference 8.50; 95% CI - 11.99 to 42; p = 0.36). During FP, women with heavy flow had shorter performance in the GXT (t = - 2.5; p = 0.01), demonstrating an r² = 0.32. In LP, for the women who reported not having the perception of the influence of the menstrual cycle on exercise, the total test time was longer (t = 2.55; p = 0.01), with an r² = 0.45.

CONCLUSION

There was no difference in physical performance between FP and LP. However, menstrual flow intensity and perception of cycle interference demonstrated a decrease in TTE.

Human circadian rhythm studies: Practical guidelines for inclusion/exclusion criteria and protocol

As interest in circadian rhythms and their effects continues to grow, there is an increasing need to perform circadian studies in humans. Although the constant routine is the gold standard for these studies, there are advantages to performing more naturalistic studies. Here, a review of protocols for such studies is provided along with sample inclusion and exclusion criteria. Sleep routines, drug use, shift work, and menstrual cycle are addressed as screening considerations. Regarding protocol, best practices for measuring melatonin, including light settings, posture, exercise, and dietary habits are described. The inclusion/exclusion recommendations and protocol guidelines are intended to reduce confounding variables in studies that do not involve the constant routine. Given practical limitations, a range of recommendations is provided from stringent to lenient. The scientific rationale behind these recommendations is discussed. However, where the science is equivocal, recommendations are based on empirical decisions made in previous studies. While not all of the recommendations listed may be practical in all research settings and with limited potential participants, the goal is to allow investigators to make well informed decisions about their screening procedures and protocol techniques and to improve rigor and reproducibility, in line with the objectives of the National Institutes of Health.

Sexual Desire in Women: Paradoxical and Nonlinear Associations with Anxiety and Depressed Mood

The aim of the present study was to expand previous findings regarding paradoxical effects of negative mood on sexual desire. This was done by considering the full range of depressed mood and anxiety symptoms and using methods that are unaffected by recall bias and that don't require participants to infer causal associations between their mood and sexual desire. A convenience sample of 213 university students completed daily questionnaires for approximately two months. Multilevel random-effects models were used to estimate average effects for the entire sample and to test for variability across participants in the associations between negative mood and sexual desire, controlling also for potential influences of the menstrual cycle. Previous findings showing that some women report decreased sexual desire and others increased sexual desire when depressed or anxious were confirmed. More importantly, for both depressed mood and anxiety, results demonstrated the presence of within-person paradoxical associations, whereby there were some women for whom both low and high levels of negative mood were associated with the same change (an increase or a decrease) in sexual desire. Related to these diverse response patterns, paradoxical associations between negative mood and sexual desire were also present at low levels of negative mood. The discussion underlines the importance of considering individual variability and multifactorial nonlinear models when studying sexual desire.

Affective Risk Associated With Menstrual Cycle Symptom Change

In the present study we test whether cyclical changes in affective symptoms of the menstrual cycle are associated with higher mean levels of those same symptoms. Using prospective daily reports across two full menstrual cycles, from two samples of female University students (n = 213; n = 163), we applied both quartic polynomial regressions and cosine regressions to model cyclical change in symptoms, and to test for mean-level differences in symptoms across the resulting trajectory patterns. Counter to prior findings, but consistent with theoretical expectations, these results show that females who experience menstrual cycle-related changes in affect (whether a perimenstrual or mid-cycle increase) are at risk for higher average levels of affective symptoms. These results suggest that the mid-cycle group should be recognized as a target for future research that is associated with increased risk for chronic negative affective symptoms.

Tracking Sleep, Temperature, Heart Rate, and Daily Symptoms Across the Menstrual Cycle with the Oura Ring in Healthy Women

Background and Objective

The ovulatory menstrual cycle is characterized by hormonal fluctuations that influence physiological systems and functioning. Multi-sensor wearable devices can be sensitive tools capturing cycle-related physiological features pertinent to women’s health research. This study used the Oura ring to track changes in sleep and related physiological features, and also tracked self-reported daily functioning and symptoms across the regular, healthy menstrual cycle.

Methods

Twenty-six healthy women (age, mean (SD): 24.4 (1.1 years)) with regular, ovulatory cycles (length, mean (SD): 28.57 (3.8 days)) were monitored across a complete menstrual cycle. Four menstrual cycle phases, reflecting different hormone milieus, were selected for analysis: menses, ovulation, mid-luteal, and late-luteal. Objective measures of sleep, sleep distal skin temperature, heart rate (HR) and vagal-mediated heart rate variability (HRV, rMSSD), derived from the Oura ring, and subjective daily diary measures (eg sleep quality, readiness) were compared across phases.

Results

Wearable-based measures of sleep continuity and sleep stages did not vary across the menstrual cycle. Women reported no menstrual cycle-related changes in perceived sleep quality or readiness and only marginally poorer mood in the midluteal phase. However, they reported moderately more physical symptoms during menses (p < 0.001). Distal skin temperature and HR, measured during sleep, showed a biphasic pattern across the menstrual cycle, with increased HR (p < 0.03) and body temperature (p < 0.001) in the mid- and late-luteal phases relative to menses and ovulation. Correspondingly, rMSSD HRV tended to be lower in the luteal phase. Further, distal skin temperature was lower during ovulation relative to menses (p = 0.05).

Conclusion

The menstrual cycle was not accompanied by significant fluctuations in objective and perceived measures of sleep or in mood, in healthy women with regular, ovulatory menstrual cycles. However, other physiological changes in skin temperature and HR were evident and may be longitudinally tracked with the Oura ring in women over multiple cycles in a natural setting.

Symptom fluctuation over the menstrual cycle in anxiety disorders, PTSD, and OCD: a systematic review

Anxiety disorders are more prevalent and severe in women than men. Extant research suggests that the menstrual cycle modulates the severity and expression of anxiety symptoms across a range of disorders. The aims of this systematic review were to synthesise the existing literature investigating menstrual phase-related fluctuations in symptoms of anxiety disorders, and related conditions PTSD and OCD, in menstruating women, and to evaluate the methodologies used. PsycINFO and PubMed were searched through to April 2021 for studies that measured and compared symptoms of a diagnosed anxiety disorder, PTSD, or OCD, between at least two menstrual phases. Fourteen studies meeting inclusion criteria were identified. The review revealed evidence for exacerbation of a broad range of symptoms in panic disorder, PTSD, social anxiety disorder, and generalised anxiety disorder, around the weeks prior to and post menses onset, coincident with elevated but declining ovarian hormones, and low hormone levels, respectively. Effects were heterogenous between individuals and different symptom types. Key methodological weaknesses included sub-optimal and inconsistent means of defining and identifying menstrual phases, low sample representativeness, and small sample sizes. Menstrual fluctuations in anxiety symptoms appear to be a feature of anxiety disorders, PTSD, and OCD, but likely only occur in a subset of women. Future research in this field could better manage and account for such heterogeneity by using group-based trajectory modelling in larger sample sizes and using pre-screening to recruit women with known histories of menstrual fluctuation in anxiety symptoms.

Subjective sleep quality and characteristics across the menstrual cycle in women with and without Generalized Anxiety Disorder

OBJECTIVE

Past studies have found that various psychiatric symptoms fluctuate over the menstrual cycle. Sleep disturbance is a transdiagnostic feature of psychiatric conditions and is associated with several symptoms that exhibit menstrual fluctuations. Although some evidence indicates that subjective sleep quality changes over the menstrual cycle in healthy women, no studies have investigated whether sleep fluctuates over the menstrual cycle in psychiatric populations, other than premenstrual dysphoric disorder.

METHODS

The present study used a mixed between- within-groups design to compare self-reported sleep characteristics (sleep onset latency, number and duration of night-time awakenings, and total sleep time), sleep quality, insomnia symptoms, and daytime sleepiness in women with (n = 31) and without (n = 32) generalized anxiety disorder (GAD) at two time points within a single menstrual cycle - the early-follicular (low ovarian hormones) and mid-luteal (high ovarian hormones) phases.

RESULTS

Women with GAD reported lower sleep quality, more insomnia symptoms, and more daytime sleepiness (η_p² = 0.13-0.14), but comparable sleep characteristics, compared to women without GAD. In both groups, sleep variables remained stable over the menstrual phases examined. Within-person changes in estradiol and progesterone between the two menstrual phases were mostly not associated with within-person changes in sleep variables, except that larger increases in estradiol were associated with a reduction in the number of night-time awakenings from the early-follicular to mid-luteal phases (β = -0.26).

CONCLUSION

These findings indicate that subjective sleep disturbance, unlike other psychiatric symptoms, may not be modulated by the menstrual cycle and ovarian hormones during the phases examined in this study.

Evolution, the Menstrual Cycle, and Theoretical Overreach

A considerable amount of recent psychological research has attributed a variety of menstrual-cycle-related changes in social behavior to evolutionarily adaptive functions. Although these studies often draw interesting and unusual conclusions about female emotion and behavior within evolutionary theory, their significant limitations have not yet been addressed. In this article, we outline several methodological and conceptual issues related to the menstrual cycle that constitute threats to the internal validity and theoretical integrity of these studies. We recommend specific guidelines to address these issues and emphasize the need to apply more comprehensive and sophisticated theoretical structures when considering menstrual-cycle-related changes in emotion and behavior.

The Effect of Sleep Deprivation on Recognition of Ambiguous Emotional Facial Expressions in Individuals With ADHD

Objective: The present study sought to investigate whether young adults with ADHD have more difficulty recognizing emotional facial expressions compared with young adults without ADHD, and whether such a difference worsens following sleep deprivation. Method: Thirty-one young men (M = 25.6) with (n = 15) or without (n = 16) a diagnosis of ADHD were included in this study. The participants were instructed to sleep 7 hr or more each night for one week, and their sleep quality was monitored via actigraph. Subsequently, the participants were kept awake in a controlled environment for 30 hr. The participants completed a visual emotional morph task twice-at the beginning and at the end of this period. The task included presentation of interpolated face stimuli ranging from neutral facial expressions to fully emotional facial expressions of anger, sadness, or happiness, allowing for assessment of the intensity threshold for recognizing these facial emotional expressions. Results: Actigraphy data demonstrated that while the nightly sleep duration of the participants with ADHD was similar to that of participants without ADHD, their sleep efficiency was poorer. At the onset of the experiment, there were no differences in recognition thresholds between the participants with ADHD and those without ADHD. Following sleep deprivation, however, the ADHD group required clearer facial expressions to recognize the presence of angry, sad, and, to a lesser extent, happy faces. Conclusion: Among young adults with ADHD, sleep deprivation may hinder the processing of emotional facial stimuli.

Effects of Sleep Deprivation on Blood Glucose, Food Cravings, and Affect in a Non-Diabetic: An N-of-1 Randomized Pilot Study

Sleep deprivation is a prevalent and rising health concern, one with known effects on blood glucose (BG) levels, mood, and calorie consumption. However, the mechanisms by which sleep deprivation affects calorie consumption (e.g., measured via self-reported types of craved food) are unclear, and may be highly idiographic (i.e., individual-specific). Single-case or “n-of-1” randomized trials (N1RT) are useful in exploring such effects by exposing each subject to both sleep deprivation and baseline conditions, thereby characterizing effects specific to that individual. We had two objectives: (1) To test and generate individual-specific N1RT hypotheses of the effects of sleep deprivation on next-day BG level, mood, and food cravings in two non-diabetic individuals; (2) To refine and guide a future n-of-1 study design for testing and generating such idiographic hypotheses for personalized management of sleep behavior in particular, and for chronic health conditions more broadly. We initially did not find evidence for idiographic effects of sleep deprivation, but better-refined post hoc findings indicate that sleep deprivation may have increased BG fluctuations, cravings, and negative emotions. We also introduce an application of mixed-effects models and pancit plots to assess idiographic effects over time.

Associations of mental health and sleep duration with menstrual cycle irregularity: a population-based study

This study aimed to examine whether the characteristics of mental health and sleep duration, alone or in combination, are associated with menstrual cycle irregularity. This population-based, cross-sectional study analyzed the data from 4445 women aged 19-49 years, who participated in the Korea National Health and Nutrition Examination Survey 2010-2012. A structured questionnaire was used to assess mental health characteristics, sleep duration, and menstrual cycle irregularity. A multivariable logistic regression analysis was performed. High stress, depressive mood, and suicidal ideation were associated with increased risk of menstrual cycle irregularity after adjusting for confounding variables (odds ratio [95% confidence interval] = 1.33 [1.07-1.65], 1.56 [1.17-2.07], and 1.37 [1.01-1.87], respectively). Short sleep duration (≤ 5 h a day) was significantly associated with higher odds of severe menstrual cycle irregularity with menstrual interval of greater than 3 months (2.67 [1.35-5.27]). Participants with sleep duration of ≤ 5 h a day with psychological stress, depressive mood, or suicidal ideation had higher odds of menstrual cycle irregularity (1.96 [1.26-3.05], 2.86 [1.50-5.44], and 2.25 [1.18-4.29]). This study suggests positive associations of mental health problems and short sleep duration with menstrual cycle irregularity among Korean female adults. Therefore, strategies to deal with psychological stress, depressive mood, and sleep duration are needed for improving the reproductive health of women suffering from menstrual disturbances.

Menstrual cycle rhythmicity: metabolic patterns in healthy women

The menstrual cycle is an essential life rhythm governed by interacting levels of progesterone, estradiol, follicular stimulating, and luteinizing hormones. To study metabolic changes, biofluids were collected at four timepoints in the menstrual cycle from 34 healthy, premenopausal women. Serum hormones, urinary luteinizing hormone and self-reported menstrual cycle timing were used for a 5-phase cycle classification. Plasma and urine were analyzed using LC-MS and GC-MS for metabolomics and lipidomics; serum for clinical chemistries; and plasma for B vitamins using HPLC-FLD. Of 397 metabolites and micronutrients tested, 208 were significantly (p < 0.05) changed and 71 reached the FDR 0.20 threshold showing rhythmicity in neurotransmitter precursors, glutathione metabolism, the urea cycle, 4-pyridoxic acid, and 25-OH vitamin D. In total, 39 amino acids and derivatives and 18 lipid species decreased (FDR < 0.20) in the luteal phase, possibly indicative of an anabolic state during the progesterone peak and recovery during menstruation and the follicular phase. The reduced metabolite levels observed may represent a time of vulnerability to hormone related health issues such as PMS and PMDD, in the setting of a healthy, rhythmic state. These results provide a foundation for further research on cyclic differences in nutrient-related metabolites and may form the basis of novel nutrition strategies for women.