Will Oat Milk Give You Too Much Estrogen?

There are estrogen compounds in it, but that’s ignoring a vital part of the story

Sam Westreich, PhD
Sharing Science
Published in
6 min readMar 3, 2022


a woman in ecstasy, clutching a glass of milk to her chest.
Milk — it’s amazing with cookies, but is it filled with hormones? Photo by engin akyurt on Unsplash

Before plant-based meat options became more commonplace in stores, there were plenty of options for faux milks. For those who either are lactose intolerant, or simply want to make choices to cause less suffering for cows, there are other milk options.

Almond milk, soy milk, oat milk… it turns out that a lot of plant products can be made into a substance that is at least somewhat similar to milk.

But not everyone is on board with plant-based milks. One commonly expressed concern is that these plant milks are rumored to contain estrogen compounds, which could have hormonal changes in the drinker.

I get it, fellas. We all want to feel confident in our masculinity. And there are fears that taking in estrogen may lead to hormone imbalances, challenges with muscle building, fertility, and other concerns.

But do plant-based milks really contain estrogen? And does consuming that estrogen provoke any effects in the drinker?

Let’s get a deep, long drink… of knowledge.

Estrogen is a class, not a compound

When we usually talk about estrogen, we’re usually, actually talking about a specific compound called estradiol. Estradiol is the predominant estrogen hormone that is expressed in women during puberty, and it’s highest both in terms of overall level, and level of activity that it drives.

But there are other types of estrogen. These include estrone, estriol, and estetrol, all compounds with slightly different molecular structures — and different effects.

In pregnancy, estriol is the predominant form of estrogen, and after menopause, estrone takes over. The fourth estrogen type found in people, estetrol, is only produced during pregnancy.

Estrogens aren’t just in human women. They’re also in men, although at lower concentrations than in women. Estrogens are synthesized in all vertebrates, as well as some insects. And going even further than that, there are phytoestrogens, estrogen-like compounds that are present in plants.



Sam Westreich, PhD
Sharing Science

PhD in genetics, bioinformatician, scientist at a Silicon Valley startup. Microbiome is the secret of biology that we’ve overlooked.