What hormones are added to beef?

December 23, 2025 •

3 min read

According to the USDA and FDA, six specific hormones are approved for growth promotion in beef cattle. These can be natural or synthetic and are used to increase growth efficiency and produce leaner beef. Consumers often have questions about what hormones are added to beef, their safety, and the regulations surrounding their use.

Quick Summary

An overview of the six natural and synthetic hormones approved for beef production, detailing their purpose, administration, and regulatory oversight by bodies like the FDA.

Key Points

Six Approved Hormones: The FDA has approved six hormones for beef cattle growth: estradiol, progesterone, testosterone, and their synthetic counterparts, zeranol, trenbolone acetate, and melengestrol acetate (MGA).
Purpose is Efficiency: These hormones increase growth rate and improve feed efficiency, allowing cattle to reach market weight faster with less feed.
Strict Regulation: In the U.S., the FDA and USDA regulate and monitor the use of these hormones, setting strict safety standards for residues in meat.
Low Human Exposure: The amount of hormone residue in treated beef is extremely low, significantly less than hormones produced naturally by the human body or found in other common foods.
Method of Delivery: Most growth hormones are delivered via a slow-release implant in the animal's ear, which is discarded during processing.
Organic vs. Conventional: Labels like "No Added Hormones" or "Organic" indicate the animal was not given additional hormones, but all beef naturally contains hormones.
EU Ban: The European Union bans the use and import of growth-promoting hormones in cattle due to differing safety conclusions and consumer perception.

The use of growth-promoting hormones in beef production is a practice widely adopted in countries like the United States, Canada, and Australia, but banned in the European Union. These hormones are administered to increase the rate of growth and improve feed efficiency, which ultimately impacts the cost of beef production. Understanding the types of hormones, how they are used, and how they are regulated is key for any consumer.

The Six Hormones Approved for Beef Production

In the U.S., the Food and Drug Administration (FDA) has approved six steroid hormones for use in cattle to promote growth. These hormones can be categorized into natural and synthetic compounds.

Natural Hormones

Naturally produced by cattle, these include estradiol, progesterone, and testosterone. These are female and male sex hormones involved in growth and reproduction.

Synthetic Hormones

These are synthetic versions of natural hormones. They include Zeranol (an estrogen-like compound), Trenbolone Acetate (TBA, an androgen similar to testosterone), and Melengestrol Acetate (MGA, a progestin feed additive). These also promote growth and efficiency.

How Hormones Are Administered

Except for MGA, which is a feed additive, the other five hormones are given via time-release implants. These small pellets are placed under the skin on the animal's ear and slowly release the hormone over a period of time. The ear is discarded during processing. MGA is strictly controlled as a feed additive.

Regulation and Safety

Growth hormones are extensively regulated to ensure safety. In the U.S., the FDA and USDA are involved. The FDA requires extensive testing before approval, and the USDA's FSIS monitors meat for residues. Studies consistently find minimal hormone residues, with estrogenic activity from implanted beef being insignificant compared to hormones in other foods or produced by the human body.

Comparison of Beef Production Methods


Feature	Conventional Beef	"No Added Hormones" / Organic Beef
Added Hormones	Yes, often used for growth promotion.	No, growth-promoting hormones are prohibited.
Growth Rate	Increased and faster.	Natural.
Feed Efficiency	Improved.	Not reliant on hormone-enhanced efficiency.
Naturally Occurring Hormones	Yes, all beef contains natural hormones.	Yes, all beef contains natural hormones.
Estrogenic Activity	Slightly higher, but still minimal.	Minimal, from natural hormones.
Labeling	Standard beef labeling.	Labeled "No Added Hormones," "Raised Without Hormones," or "Organic".

Understanding the Impact on Human Health

Scientific evidence suggests a negligible effect on human health from consuming treated beef. This is due to low residue levels and the fact that humans produce much higher amounts of these hormones. The estrogenic activity in a serving of implanted beef is minimal compared to foods like eggs or tofu. Hormones are also broken down during cooking and digestion. Regulatory agencies in countries permitting their use generally consider approved hormone treatments safe.

Conclusion

The six hormones added to conventional beef are estradiol, progesterone, testosterone, zeranol, trenbolone acetate, and melengestrol acetate. They increase growth and efficiency and are regulated by agencies like the FDA. Administration is typically via ear implants or feed additives, with minimal residues in the final product. Labels like "No Added Hormones" and "Organic" offer alternatives for consumers. All beef contains natural hormones, and regulatory standards deem the residue levels in treated beef to be safe. For more information, the FDA provides guidance on Steroid Hormone Implants Used for Growth in Food-Producing Animals.

Frequently Asked Questions

The six approved hormones are the natural hormones estradiol, progesterone, and testosterone, and the synthetic hormones zeranol, trenbolone acetate, and melengestrol acetate (MGA).

Regulatory bodies like the FDA have determined that meat from animals treated with approved growth hormones is safe for human consumption. The amount of hormone residue is very low and not considered a health risk.

The level of estrogenic activity in a serving of hormone-treated beef is minuscule compared to the activity found in other common foods like eggs or tofu.

Most growth hormones are administered through a small, time-release implant placed under the skin in the animal's ear, which is discarded at slaughter. MGA is added to the feed.

The term "hormone-free" is misleading, as all living things naturally contain hormones. "No added hormones" is a regulated label indicating no extra growth hormones were administered to the animal.

Hormones are used to promote faster growth and improve feed efficiency, allowing cattle to reach market weight sooner and more efficiently.

The EU bans the use and import of growth-promoting hormones in cattle due to different conclusions about consumer health risks and a generally higher level of consumer concern about the practice.