If a woman's estrogen level plummets during menopause, and estrogen enhances the effects of oxytocin, it seems likely that her enjoyment of all the benefits of oxytocin will suffer. While the balance of risks and benefits of hormone replacement therapy remains unclear, there is clear evidence that HRT increases oxytocin after The Pause.
A study led by Kathy Light at the University of North Carolina, found that women taking estrogen replacement therapy had higher levels of an oxytocin precursor in their blood, leading to lower blood pressure under stress.
Studies of ovariectomised rats by Kirsten Uvnas-Moberg were convincing enough that she left her post as a professor at Stockholm's Karolinska Institute to found a company to develop oxytocin-based treatments for menopausal symptoms.
The "menopausal" rats had higher insulin levels and higher blood sugar. Lower levels of cortisol and growth hormone meant they had less energy. They also gained more weight than untreated rats. Five days of oxytocin treatments reversed these effects, normalizing insulin levels; the rats treated with oxytocin for ten days didn't gain as much weight, eating the same amounts of food as the fatties did.
Some of that weight gain could be down to hormonal changes in appetite, also due to less oxytocin running through the veins. Researchers at the University of Pittsburgh found that mice without the oxytocin-producing gene had a sweet tooth, consuming a lot more sweetened water than normal mouse kept under the same conditions. They also hankered after salt -- bring on the potato chips!
But rats in Uvnas-Moberg's lab that got estrogen along with oxytocin fared even better. They had lower levels of stress hormones and higher levels of growth hormones than rats that got oxytocin alone.
The body of a menopausal woman may not be able to make the most of her everyday supply of oxytocin. HRT could boost its effects, but, whether or not she goes that route, there are plenty of strategies to naturally boost the oxytocin response.