Questions and Answers - Hormonal Growth Promoters

What is the issue?

The use of hormonal growth promoters in beef cattle is an issue which has sparked much debate around the world. They are approved for use in Canada and the United States (US), however, the use of hormonal growth promoters is banned in the European Union (EU).

Public concerns about the use of hormonal growth promoters relate to questions about their impact on human health; in particular, whether these compounds may be cancer-causing and could adversely affect human health. Scientific research to date has not demonstrated that food products from animals treated with these hormonal growth promoters pose a threat to human health.

What are hormonal growth promoters?

Hormonal growth promoters are naturally occurring or synthetic products. They are approved for use in beef cattle. The effect of hormonal growth promoters (HGPs) is to increase lean tissue growth. Fat deposition is reduced and since fat is so energy dense, food conversion efficiency is increased. The result is a healthier product which is produced at a lower cost to the consumer.

What is the growth hormone (somatotropin)?

The growth hormone (somatotropin) is a naturally occurring substance in both humans and animals. It is responsible for skeletal, organ and cell growth.

What is Recombinant bovine somatotropin (rBST)?

Recombinant bovine somatotropin (rBST) is a synthetic version of the naturally occurring growth hormone somatotropin. It is approved for use in the US to increase the production of milk in dairy cattle. However, it is not approved for sale in Canada.

Why is rBST not approved for use in Canada?

rBST was reviewed by Health Canada in the 1990's. Although it was determined that it did not pose a health risk to humans, there were animal health concerns, and therefore it was never approved for sale in Canada.

Which products are approved in Canada?

There are six hormonal growth promoters approved in Canada for use in beef cattle: three natural - progesterone, testosterone and estradiol-17ß; and three synthetic - trenbolone acetate (TBA), zeranol and melengestrol acetate (MGA). Hormonal growth promoters are not approved for use in any species other than beef cattle.

How are they administered to the animals?

All HGPs are administered as subcutaneous implants (behind the ear), except for melengestrol acetate (MGA) which is supplied as a feed additive.

For more information on the veterinary drug approval process, please refer to our Web site at:

For information on the monitoring of residues in foods derived from animals, please refer to the  Canadian Food Inspection Agency's Web site at:

How can I keep up-to-date on this issue?

As new data on hormonal growth promoters become available, Health Canada will continue to provide information on our Web site.

Contact us:

Veterinary Drugs Directorate
Telephone: 613-321-4239

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