Marihuana effects on pituitary and gonadal hormones in women

A series of studies were carried out to assess the acute and chronic effect s of marihuana smoking on pituitary and gonadal hormone levels in women. Pl asma samples for analysis of luteinizing hormone (LH), estradiol, progester one, and prolactin were obtained from 16 women prior to and following smoki ng one marihuana cigarette that contained 1.8% THC or a l-g placebo cigaret te. A small but statistically significant decrement (p < 0.02) in LI-I leve ls was observed following marihuana smoking in contrast to placebo smoking during the luteal phase of the menstrual cycle. However, the decrease in LH probably was not biologically significant since all LH levels were within the normal range for healthy adult women. Marihuana smoking was also follow ed by a small but statistically significant decrease in prolactin levels du ring the luteal phase of the menstrual cycle, but this probably was not bio logically significant. The hormonal effects of daily marihuana smoking over 21 days were studied in 21 women who lived on a clinical research ward for 33 days. Women worked at a simple operant task to acquire marihuana cigare ttes. Each marihuana cigarette contained 1.8% Delta(9)-THC. Blood samples f or analysis of LH, estradiol, and progesterone were collected on alternate days before, during, and after marihuana smoking. Normal ovulatory menstrua l cycles were observed, and there was no evidence of a marihuana dose-relat ed suppression of ovulation or disruption of luteal phase function in women classified as heavy (6.1 +/- 1.45 cigarettes per day), moderate (2.72 +/- 0.16 cigarettes per day) or occasional (0.90 +/- 0.22 cigarettes per day) m arihuana smokers. These data indicate that smoking marihuana at the dose le vels observed for 21 days did not disrupt the menstrual cycle in healthy ad ult women.