Oxytocin: benefits you didn’t know about

Javier Colomer 6 min. of reading Well-being habits Leave a comment

Let’s talk about a hormone that hardly anyone has heard of, at least in the fitness scene or health world: oxytocin.

We’re all used to hearing about growth hormone or insulin as anabolic hormones.

In the world of physiology, it might seem like everything’s been said, but nothing could be further from the truth.

What is Oxytocin?

Oxytocin is a hormone produced in cells of the hypothalamus (parvocellular and magnocellular neurons) and classically (that’s how I learned about it in med school) it’s linked to two essential physiological processes for humans:

Inducing labor
Breastfeeding (along with prolactin)

Today we’re looking at other effects of oxytocin that few know about. This post is inspired by a recent and fascinating review from Endocrine Reviews (1).

What metabolic effects does oxytocin have?

Besides its roles in labor and breastfeeding, oxytocin seems to act as a nutritional status sensor in both sexes (men and women).

It appears that OXT has an anorexigenic effect, leading to lower energy intake by acting on multiple homeostatic and neurobehavioral pathways.

Ever heard the saying “they lost their appetite, they’re in love”?

Today’s post might just explain that common phenomenon I’ve nicknamed “post-love anorexia.”

How is it produced?

Oxytocin is released in response to labor and the baby suckling at the nipple.

But there are other triggers like exercise, sex, or romantic contact that have been less studied.

What’s interesting is that available studies show weight loss due to fat mass loss, not lean mass.

Subjects increase their energy expenditure and reduce intake when exposed to high oxytocin levels.

It doesn’t stop there: oxytocin seems to be an anabolic hormone for muscle and bone.

Are we looking at the new GH?

Probably not, since its secretion pattern is much more specific, but if it could be isolated and safely administered to patients with obesity, could this be a new anti-obesity drug?

Benefits

Lipolysis

Greater fat oxidation.

Muscle anabolism

What any bodybuilder would want…

It’s also of interest for people with chronic conditions, as many develop sarcopenia over time.

We have a very interesting post about Sarcopenia. If you want to dive deeper, click on this link.

Bone anabolism

Let’s not forget bone, muscle’s close cousin, whose health is at least as important as muscle’s.

Slower gastric emptying rate, promoting fullness

It’s the same mechanism as other hormones used in obesity like GLP-1 analogs, a widely used incretin in antidiabetic and anti-obesity therapy.

If you want to know the link between Incretins and Diabetes, check out this link.

Increased insulin secretion for the same glucose load

In other words, it helps the pancreas secrete insulin when needed, potentially reducing hyperglycemia.

Changes in the microbiome

Nowadays, talking about the microbiome is talking about metabolism.

The microbiota and their metabolites have been shown to act through hundreds of different metabolic pathways.

Looks like oxytocin also influences the microbiota.

Lower calorie intake

You know, the “lover’s anorexia.”

Plus higher energy expenditure by modulating sympathetic nervous system tone.

Social effects

Oxytocin is involved in intangible and deeply human processes like empathy, affection, and love.

That’s why it’s called “the love hormone.”

Could it be used in the future to treat conditions?

That’s exactly what’s being tested:

In people with exogenous obesity (the most common);
And in patients with hypothalamic obesity (seen in some syndromes like Prader-Willi).

Several clinical trials are underway, with the administration method being one of the challenges we’re trying to solve.

Intraperitoneal, intranasal, or intravenous formulations are being studied.

Is there a way to produce it endogenously?

Yes, there are several ways, some more practical than others, to boost oxytocin secretion:

If you’re a woman:

Giving birth.
Having a baby latched on the breast.

These are the two most powerful stimuli for oxytocin release that we know of.

But also, for both sexes:

Sexual stimulation.
Affection.

Put less academically, “falling in love” seems to raise oxytocin levels in both sexes.

Conclusions

Popularly, being in love has been linked to a state of ecstasy and physiological well-being.

This is due to the secretion of a series of neuropeptides like endorphins during that beautiful period of our lives.

But interestingly, another claim about the courtship and falling in love period is “having less hunger.”

Physiology never ceases to amaze us, and this article confirms that oxytocin has systemic effects far beyond causing contractions during labor or triggering milk letdown.

Let’s hope we can soon harness these effects clinically.