Chronobiology internationalAug 1, 1996

Oral contraceptives change daily patterns of hormones, blood pressure, heart rate, skin blood flow, water loss, and skin amino acids in healthy young women

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Updated Mar 28, 2026

Abstract

Salivary melatonin was not detected in oral contraceptive (OC) users among 16 healthy women studied.

Mean systolic blood pressure was significantly higher in OC users compared to non-users (p < 0.0001).
OC users also exhibited a greater mean heart rate (p < 0.01) and increased skin blood flow (p < 0.04) than non-users.
Transepidermal water loss was higher in OC users (p < 0.02), while salivary cortisol levels were lower (p < 0.04).
Skin amino acid concentrations were reduced in OC users compared to non-users (p < 0.003).
No significant differences were found in diastolic blood pressure, grip strength, oral temperature, self-rated fatigue, or other skin variables.

Simplified

Sixteen healthy women users and nonusers of oral contraceptives (OC) volunteered to document a set of circadian rhythms. Nine were taking OC providing ethynyl estradiol (0.03-0.05 mg/24h, 21 days/month) combined with DL- or L-norgestrel or norethisterone. There was no group difference (p > 0.05) in median age (22 years), weight (57 kg), and height (162) cm). Data were obtained at fixed hours, 5 times/24h, during a 48-h span, in November. (Day activity from approximately 08:00 to approximately 23:00 h and night rest). Environmental conditions were controlled, using air-conditioned rooms of constant temperature (26 degrees +/- 0.5) and relative humidity 45% +/- 1. Both cosinor and ANOVA were used for statistical analyses. All circadian rhythms were validated with one exception: that of salivary melatonin was not detected in OC users. The 24h mean (M) exhibited group differences for certain variables: M was greater in OC than non-OC users for systolic blood pressure (p < 0.0001), heart rate (p < 0.01), skin blood flow (p < 0.04), and transepidermal water loss (p < 0.02). M was lower in OC than non-OC users in salivary cortisol (p < 0.04) and skin amino acids (p < 0.003). No group difference was detected in any other documented rhythms: diastolic blood pressure, grip strength of both hands, oral temperature, self-rated fatigue, and the skin variables of urea, lactate, triglycerides, and acid phosphatase activity.

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Oral contraceptives change daily patterns of hormones, blood pressure, heart rate, skin blood flow, water loss, and skin amino acids in healthy young women

Abstract

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