Capacity for love and labor + invitation to class exploring synergy between melatonin and oxytocin

Early life experiences can facilitate (or impede) love and labor through circadian regulatory functions

Melatonin and oxytocin support each other in labor—but what about in the rest of life?

Oxytocin, the “hug” hormone, and melatonin, the “sleep” hormone, are similarly involved in many processes of growth, resilience, and healing across the entire lifespan.

Though essential to wellbeing, oxytocin remains mysterious to us in many ways. It is a facilitator of most forms of social activity as well as health and wellness. In the context of the perinatal period, we might first think of oxytocin in terms of labor. Oxytocin is vital to the labor process.

Oxytocin has also been explored as a possible panacea for many forms of human woe¹. It is a core hormone for all mammals—and the first of the peptide hormones to be synthesized by humans in a lab. While the molecule of oxytocin itself is relatively simple, significant complications stop us from being able to easily measure and understand it in action.

Problems in the oxytocin pathways, like the melatonin pathways, not only can interfere with the labor process, but also indicate mental health, trauma, and other health issues.

However, adding synthetic versions of the hormones back doesn’t resolve these underlying problems (especially if they are stemming from a protective trauma response).

Researchers speculate about a threshold for oxytocin that may be set in early life². This threshold can make it so a person might only have a capacity to receive a certain amount of oxytocin—which could be an amount that doesn’t facilitate healthy social function.

The oxytocin system seems to be programmed in infancy with effects that may last a lifetime.

We are discovering that oxytocin (and thereby capacity for bonding, giving parental care, and other reproductive function), is regulated by the circadian rhythm. Though the exact mechanisms remain under investigation, the relationship is verified:

The circadian rhythm and the endocrine system have a bi-directional relationship, meaning strength or challenge in either system affects the other.

It makes sense that there are related issues with melatonin and oxytocin when we know that challenges to early development of the circadian rhythm also affect the development of the oxytocin system, and that both can have lifelong affects not only on wellbeing, but also on the reproductive processes³.

Disruption to circadian development in early life can lead to reproductive dysfunctions of varying levels, from challenges to puberty all the way through preterm labor, arrest of labor, recurring miscarriage, stillbirth, or complete infertility.

To finish the circadian-melatonin-oxytocin storm that can arise in labor, melatonin, is known to be a regulator of oxytocin in the uterus⁴! Doesn’t it make so much sense that labor—with it’s powerful synergy of elevated melatonin and oxytocin levels—is such a common time then for women to have hidden traumas resurface?

Melatonin receptors in the uterus sense the mother’s circulating melatonin levels to promote increased sensitivity to oxytocin in the “safest” time of day for labor onset (between sunset and dawn).

Thus, the circadian regulatory loop of melatonin and oxytocin can either facilitate a highly sensual, powerful, and even healing bonding experience in labor—or contribute to the perfect storm that leads so many down the cascade of interventions.

I invite you to explore the synergistic dynamics of melatonin and oxytocin (inside and outside of labor) in my next community class on Tuesday, November 7th at 1:00 PM Pacific.

The Synergy of Melatonin and Oxytocin, a community class for paid subscribers and guests of Brighter Days, Darker Nights:

1. Carter, C. S., Kenkel, W. M., MacLean, E. L., Wilson, S. R., Perkeybile, A. M., Yee, J. R., Ferris, C. F., Nazarloo, H. P., Porges, S. W., Davis, J. M., Connelly, J. J., & Kingsbury, M. A. (2020). Is Oxytocin "Nature's Medicine"?. Pharmacological reviews, 72(4), 829–861. https://doi.org/10.1124/pr.120.019398

2. Onaka, T., & Takayanagi, Y. (2021). The oxytocin system and early-life experience-dependent plastic changes. Journal of neuroendocrinology, 33(11), e13049. https://doi.org/10.1111/jne.13049

3. Hsu, C. N., & Tain, Y. L. (2020). Light and Circadian Signaling Pathway in Pregnancy: Programming of Adult Health and Disease. International journal of molecular sciences, 21(6), 2232. https://doi.org/10.3390/ijms21062232

4. McCarthy, R., Jungheim, E. S., Fay, J. C., Bates, K., Herzog, E. D., & England, S. K. (2019). Riding the Rhythm of Melatonin Through Pregnancy to Deliver on Time. Frontiers in endocrinology, 10, 616. https://doi.org/10.3389/fendo.2019.00616