Vince
Super Moderator
The relationship between the concentrations of melatonin and prolactin over the 24-h cycle has been investigated in a group of young men at three times in the year. Melatonin and prolactin showed a significant positive correlation (P less than 0.001) for all times during the 24-h period but with a greater contribution from concentrations during the nocturnal period, when both hormones were elevated. The positive correlation for nocturnal concentrations was evident in February and March (P less than 0.01) but was of greatest significance in June (P less than 0.001). In blood samples taken at 15-min intervals during the morning (0800-1200) and evening (2000-2400), melatonin and prolactin concentrations were not significantly correlated. Melatonin concentrations increased before prolactin during the evening and decreased before prolactin in the morning. Oral administration of 6 mg melatonin significantly stimulated prolactin release above concentrations measured after placebo administration, in both the morning (P less than 0.05) and evening (P less than 0.01) time periods; the prolactin response being greater in the evening. These results provide evidence for melatonin controlling the nocturnal increase of prolactin via its ability to stimulate prolactin release.But there's not long-term safety data, so people doing this are simply experimenting. They are also extrapolating from the benefits of normal levels over low levels. It's like saying that if 100 mg of testosterone per week makes hypogonadal men feel better then 1,000 mg per week must be 10 times better. The evidence for cancer prevention is deemed inconclusive, though there are positive associations in unblinded studies.[R]
Additionally, anyone thinking about mega-dosing should read up on the link between melatonin and prolactin.