DHEA Fluctuation Across the Menstrual Cycle
DHEA levels do not fluctuate significantly with the menstrual cycle in healthy premenopausal women, showing only random variations throughout follicular and luteal phases, unlike other androgens such as testosterone and androstenedione which demonstrate clear cyclical patterns. 1
Evidence for Lack of Cyclical Variation
The most direct evidence comes from daily measurements of plasma androgens throughout complete menstrual cycles in normal ovulating women, which demonstrated that DHEA levels showed random variations during the cycle without statistically significant cyclical patterns 1. This contrasts sharply with testosterone, dihydrotestosterone, and androstenedione, all of which exhibited clear peaks during the periovulatory period and nadirs in early follicular and late luteal phases 1.
Adrenal vs. Ovarian Origin Explains Stability
The lack of menstrual cycle fluctuation in DHEA makes physiologic sense based on its source:
- DHEA is predominantly secreted by the adrenal glands (3-4 mg/day) under ACTH control, not by the ovaries 2
- The ovary secretes only 1-2 mg/day of DHEA in the follicular phase with minimal change during the periovulatory period 2
- Steroids of predominantly adrenal origin (like DHEA) do not exhibit menstrual cycle-dependent rhythmicity, while those of predominantly gonadal origin do 3
Circadian Rhythm Persists Across All Cycle Phases
While DHEA doesn't fluctuate with menstrual phase, it does maintain a consistent circadian rhythm:
- DHEA demonstrates marked circadian variation in all three phases of the menstrual cycle (follicular, periovulatory, and luteal) 3
- Morning DHEA levels remain stable across cycle phases when comparing the same time of day 3
- The circadian amplitude may decrease slightly in the luteal phase due to higher evening values, but this represents diurnal variation, not menstrual cycle-dependent changes 3
Clinical Measurement Considerations
When measuring DHEA clinically:
- Timing within the menstrual cycle is not critical for DHEA measurement, unlike estradiol or progesterone 1, 3
- Time of day matters more than cycle phase due to circadian rhythm 3
- Salivary DHEA correlates closely with plasma free DHEA in both follicular and luteal phases 4
- Reference ranges for DHEA/DHEAS are age-dependent but not menstrual phase-dependent 5
Common Clinical Pitfall
Do not confuse DHEA with other androgens when evaluating menstrual cycle effects. Testosterone and androstenedione both peak at ovulation 1, and clinicians may incorrectly assume all androgens behave similarly. The failure of some earlier studies to detect cyclical variations in other androgens was attributed to large interindividual variation, not to actual absence of cycles 1—but for DHEA specifically, the lack of cyclical variation is real and consistent.