Does Lactose-Free Milk Have Hormones?

December 28, 2025 •

3 min read

Over 68% of the world's population has some degree of lactose malabsorption, making lactose-free milk a popular choice for many. But a common question that arises for health-conscious consumers is, "Does lactose-free milk have hormones?". The short answer is yes, but not in the way many people assume. The longer, more nuanced answer involves understanding the distinction between naturally occurring hormones and synthetic additions.

Quick Summary

All cow's milk naturally contains small amounts of hormones, including sex hormones and growth hormones. Since lactose-free milk is still dairy milk, it contains these same natural hormones. It is not different from conventional milk in this regard, though labeling may indicate if synthetic rBST was avoided.

Key Points

Natural Hormones: All cow's milk, including lactose-free, contains naturally occurring hormones like estrogen and progesterone, a product of the cow's biology.
Synthetic Hormones: The presence of synthetic hormones, such as rBST, is a separate issue; many dairy companies voluntarily avoid using them and label their products accordingly.
Processing Does Not Remove Hormones: The process of making milk lactose-free involves adding the enzyme lactase to break down sugar, not removing or affecting the hormonal content.
Labels Need Interpretation: Phrases like 'rBST-free' indicate the absence of synthetic hormones, but not of all natural hormones.
Plant-Based Alternatives: For a truly hormone-free option, plant-based milks are the only choice, though some like soy contain naturally occurring phytoestrogens.
Safety Consensus: Major health organizations and regulatory bodies generally agree that milk from cows treated with rBST is safe for human consumption, though some debate remains.

All Milk, Including Lactose-Free, Contains Natural Hormones

It is a fundamental biological fact that all animal-based food products, including milk, naturally contain hormones. These are naturally occurring chemical messengers, such as estrogen and progesterone, which are present in cows' bodies and, consequently, their milk. This is completely normal and is a result of the cow's natural biological processes, particularly during pregnancy, when hormone levels are higher. Lactose-free milk is produced by adding the enzyme lactase to regular dairy milk to break down the lactose (milk sugar), and this process does not remove or alter the inherent hormonal content. Therefore, claiming that lactose-free milk is entirely hormone-free would be misleading.

The Controversial Story of Synthetic Growth Hormones (rBST)

The primary source of confusion regarding hormones in milk often stems from the use of recombinant bovine somatotropin (rBST), a synthetic growth hormone. Developed to increase milk production in cows, rBST's use has been highly debated and has led to consumer concerns over its potential effects on human health, although regulatory bodies like the FDA have deemed milk from treated cows safe. Importantly, many dairy farms have voluntarily phased out the use of rBST, and milk from cows not treated with it is often labeled as such. This labeling, however, does not mean the milk is free of all hormones, only that it is free of supplemental synthetic hormones.

Labeling and What It Tells You

When shopping for milk, the labeling can be a crucial guide, but it requires careful interpretation. Labels like "rBST-free" or "no artificial growth hormones" refer specifically to the synthetic rBST and do not mean the product is completely hormone-free. For those who wish to avoid synthetic hormones, seeking milk with these labels is the correct approach. Additionally, organic milk is, by USDA regulation, produced without the use of synthetic growth hormones.

How is Lactose-Free Milk Made?

The process of creating lactose-free milk involves the addition of the enzyme lactase. This enzyme breaks down lactose into two simpler, more digestible sugars: glucose and galactose. This process is purely about breaking down a sugar and has no impact on the protein structure or hormonal content of the milk itself. The milk is first pasteurized, and then lactase is added to it, after which it is re-pasteurized and packaged. Sometimes, ultra-filtration is used to remove some lactose before the lactase is added, which can result in a less sweet taste.

The Different Faces of Hormones: Animal Milk vs. Plant-Based

For those seeking a truly hormone-free beverage, plant-based alternatives are the answer. Unlike dairy milk, these products do not originate from animals and therefore contain no animal-derived hormones. However, it is important to note that plant-based milks may contain phytoestrogens, which are compounds that can mimic estrogen in the body, although their effects on human health are still being studied.

Comparison of Lactose-Free and Plant-Based Milk Hormones


Feature	Lactose-Free Cow's Milk	Plant-Based Milks (Soy, Almond, etc.)
Origin	Derived from dairy cows	Derived from plants (e.g., soybeans, almonds)
Natural Hormones	Contains naturally occurring bovine hormones (estrogen, progesterone)	Contains no bovine hormones
Synthetic Hormones (rBST)	May be from cows not treated with rBST (check label)	Not applicable
Phytoestrogens	Minimal to none	Can contain phytoestrogens (e.g., soy milk)
Processing	Lactase enzyme added to break down lactose	Processes vary by type, may involve soaking, grinding, and filtering
Hormonal Impact on Humans	Ingestion of bovine hormones from milk is not proven to significantly alter human hormone levels.	Effects of phytoestrogens from sources like soy are widely debated and require more research.

Conclusion: Understanding the Full Picture

In conclusion, lactose-free milk does contain hormones, just like regular dairy milk, because it comes from dairy cows. The confusion typically arises from the distinction between naturally occurring hormones and synthetic ones like rBST. While many companies now offer milk from cows not treated with rBST, it's crucial for consumers to understand that no dairy product can be completely hormone-free. For a truly hormone-free beverage, plant-based alternatives are the only option, though these can come with their own set of considerations, such as the presence of phytoestrogens. Making an informed choice depends on understanding these key differences and prioritizing what is most important for your personal health and dietary needs. For further research on the nuances of hormones in dairy, you can explore academic studies on the topic.

Frequently Asked Questions

There is no difference in the hormonal content between lactose-free and regular cow's milk, as both are sourced from dairy cows and naturally contain hormones. The only difference is the addition of the enzyme lactase to break down the milk sugar, lactose.

No, they are not. 'rBST-free' means the milk comes from cows not treated with recombinant bovine somatotropin, a synthetic hormone. However, it will still contain naturally occurring hormones, so it is not truly 'hormone-free'.

No, pasteurization does not significantly affect the steroid hormone levels (like estrogen) in milk. Studies have shown that even ultra-high-temperature (UHT) pasteurization does not degrade these hormones.

Organic milk and conventional milk (including its lactose-free version) can have comparable levels of naturally occurring hormones. The key difference is that organic milk standards prohibit the use of supplemental synthetic growth hormones like rBST.

Cow's milk naturally contains small amounts of various steroid hormones, including estrogen and progesterone, which are part of the cow's reproductive and metabolic cycles.

Yes, major health organizations have stated that the small amounts of hormones naturally present in milk are safe for human consumption and do not significantly affect human hormone levels, as they are largely broken down during digestion.

Plant-based milks, such as almond or oat milk, contain no animal-derived hormones. However, some, like soy milk, contain phytoestrogens, which are plant-based compounds with estrogen-like effects. The health impacts of these are still debated and are different from animal hormones.