Does Sheep Milk Contain Estrogen? Unpacking the Science

January 13, 2026 •

3 min read

A 2019 review published in the journal News-Medical.Net identified estrogen as one of the key hormones found naturally in milk from all mammals, including sheep. This means that, yes, sheep milk does contain estrogen, alongside other natural hormones like progesterone. However, the presence of these hormones is a normal biological occurrence, not a cause for concern in typical dietary consumption.

Quick Summary

Sheep milk naturally contains small, safe amounts of estrogen and other hormones, similar to milk from other mammals, including cows and humans. These hormones are digested and do not remain active in the body. The health benefits of sheep milk's rich nutrient profile generally outweigh any hormonal concerns related to its minimal, natural hormone content.

Key Points

Natural Presence: All milk from mammals, including sheep, naturally contains small amounts of hormones, including estrogen.
Low Concentrations: The levels of estrogen and other hormones in sheep milk are low and not considered a health risk for most adults.
Efficient Digestion: The human digestive system effectively breaks down these hormones, preventing them from being absorbed in their active form.
Superior Nutrition: Sheep milk is richer in protein, fat, calcium, and B vitamins than cow milk, offering significant nutritional benefits.
A2 Protein Advantage: Containing only the A2 beta-casein protein, sheep milk is often easier to digest for individuals with cow milk sensitivities.
Bioactive Compounds: Sheep milk is a good source of beneficial compounds like CLA and MCTs, which contribute to its health-promoting properties.

The Biological Reality: Hormones in All Milk

All milk produced by mammals, including sheep, goats, cows, and humans, contains naturally occurring hormones. This is an essential aspect of mammalian physiology, as hormones like estrogen and progesterone play crucial roles in reproduction and lactation. The presence of estrogen in sheep milk is not an anomaly but a biological certainty rooted in the ewe's reproductive cycle. The levels of these hormones can vary depending on factors such as the ewe's age, breed, and stage of lactation, but they remain at very low concentrations.

Are the Hormones in Sheep Milk a Health Concern?

For most people, the trace amounts of natural hormones in sheep milk do not pose a health risk. The human digestive system is highly efficient at breaking down and neutralizing these hormones before they can be absorbed in their active form. A comprehensive review published in the journal Nutrients concluded that estrogen levels in milk are generally too low to affect adult health, though more research on potential effects in infants and children is warranted. It's also important to distinguish between naturally occurring hormones and synthetic hormonal growth promotants, which are often heavily regulated or banned in many countries' dairy industries.

Sheep Milk vs. Cow Milk: A Nutritional and Hormonal Comparison

When considering dairy sources, many people compare sheep milk and cow milk. While both contain natural hormones, their overall nutritional profiles and digestibility differ significantly. Sheep milk is often promoted as a nutrient-dense alternative with a different protein structure and smaller fat globules, which some find easier to digest than cow milk.

Nutritional Comparison: Sheep Milk vs. Cow Milk (per 100g)


Nutrient	Sheep Milk (approx.)	Cow Milk (approx.)	Key Difference
Protein	5.4g	3.2g	Sheep milk has significantly more protein.
Fat	7g	3.9g	Sheep milk has a higher fat content, with smaller, more easily digestible fat globules.
Calcium	197.5mg	112mg	Sheep milk contains notably more calcium.
B Vitamins	Higher levels of B12 and B2	Lower levels	Sheep milk is a richer source of certain B vitamins.
Lactose	Slightly lower total content	Slightly higher total content	While still present, many with lactose sensitivity report better tolerance for sheep milk due to its different protein structure.

The A1 vs. A2 Protein Distinction

One key factor contributing to sheep milk's superior digestibility for some people is its protein composition. Standard cow milk often contains both A1 and A2 beta-casein proteins. The A1 protein has been linked to digestive discomfort in some individuals, leading to symptoms similar to lactose intolerance. Sheep milk, however, contains only the A2 beta-casein protein, making it a potentially gentler alternative for those with sensitivities.

Bioactive Compounds and Health Benefits

Beyond its fundamental macronutrients, sheep milk is packed with various bioactive compounds that offer additional health-promoting properties.

Conjugated Linoleic Acid (CLA): Sheep milk has a higher concentration of CLA compared to cow's and goat's milk. This fatty acid has been linked to several health benefits, including potential anticancer properties and support for the immune system.
Medium-Chain Fatty Acids (MCTs): The higher levels of MCTs in sheep milk are more easily metabolized by the body, providing a quick source of energy and contributing to a feeling of fullness.
Immunoglobulins and Nucleotides: Bioactive peptides and immunoglobulins in sheep milk may have antibacterial, antiviral, and anti-inflammatory effects.
Vitamins and Minerals: Sheep milk is an excellent source of essential vitamins like B12, riboflavin, and calcium, which are crucial for bone health and neurological function.

Conclusion: Making an Informed Choice

In conclusion, the claim that sheep milk contains estrogen is accurate, but it is a natural, normal biological phenomenon. The small amounts of estrogen present in sheep milk are typically broken down by the digestive system and are not considered a health risk for the average adult. When deciding between different types of milk, it's more beneficial to focus on the overall nutritional profile and how your body tolerates the milk rather than fixating on the presence of natural hormones. For those seeking a highly digestible, nutrient-dense alternative to cow's milk, sheep milk presents a compelling option with a rich array of vitamins, minerals, and bioactive compounds. As always, individuals with specific health concerns, particularly hormone-sensitive conditions, should consult a medical professional.

Dairy.com.au provides a straightforward explanation of natural hormones in dairy, affirming their presence in milk from all mammals.

Frequently Asked Questions

No, for the majority of people, the natural, low concentrations of estrogen in sheep milk are not considered harmful. The digestive system effectively breaks down and deactivates these hormones before they can be absorbed into the body in active form.

Yes, all milk from mammalian species, including sheep, cows, goats, and humans, contains naturally occurring hormones like estrogen and progesterone as part of their biological function.

Both sheep and cow milk contain natural hormones. The key difference lies in other factors, such as sheep milk's higher concentration of certain nutrients and the presence of only the A2 beta-casein protein, which makes it more digestible for some people.

Yes, dairy products like cheese and yogurt derived from sheep milk will still contain these natural hormones. However, the digestive process and breakdown during processing minimize any potential effects on the consumer.

Sheep milk is often easier to digest for some individuals because its protein structure contains only the A2 beta-casein protein, unlike the A1 protein found in many types of cow milk that can cause discomfort.

While hormones can sometimes become more concentrated in certain processed products like higher-fat cheeses, they are still broken down during digestion and not absorbed in their active state.

While not a concern for most, individuals with hormone-sensitive health conditions should consult with a doctor or endocrinologist. It is a good practice for anyone with medical concerns to seek professional advice regarding their diet.