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  1. Product Safety Information

Fertagyl® (gonadorelin acetate) - Veterinarians

Dear Bovine Veterinarian:

In April 2015, FDA approved the third gonadotropin releasing hormone (GnRH) product, Fertagyl® (gonadorelin), for estrous synchrony in lactating dairy cows. Fertagyl (Abbreviated New Animal Drug Application 200-134) is a sterile injectable solution of gonadorelin acetate, and when used with Estrumate® (cloprostenol injection) as part of a synchronization regimen, the drug can be used to synchronize estrous cycles to allow for fixed time artificial insemination in lactating dairy cows. FDA wants to remind you of the benefits of using approved drugs in your practice.

Manufactured by Intervet, Inc., Fertagyl is a prescription drug available in 20 mL and 100 mL multi-dose vials. The concentration is 43 mcg gonadorelin (as gonadorelin acetate) per mL of solution. Please refer to Animal Drugs @ FDA for more information about Fertagyl.

Benefits of FDA Approval

FDA rigorously evaluates an animal drug before approving it. As part of the approval process, the drug company must prove to FDA that:

  • The drug is safe and effective for a specific use in a specific animal species. For a drug intended for use in food-producing animals, the company must also prove that food made from animals treated with the drug is safe for people to eat;
  • The manufacturing process is adequate to preserve the drug’s identity, strength, quality, and purity. The company must show that the drug can be consistently produced from batch to batch; and
  • The drug’s labeling is truthful, complete, and not misleading. The company must make sure that the labeling contains all necessary information to use the drug safely and effectively and includes the risks associated with the drug.

FDA’s role does not stop after the agency approves an animal drug. As long as the drug company markets the animal drug, the agency continues to monitor:

  • The drug’s safety and effectiveness. Sometimes, the agency’s post-approval monitoring uncovers safety and effectiveness issues that were unknown at the time of approval;
  • The manufacturing process to ensure quality and consistency are maintained from batch to batch;
  • The drug’s labeling to make sure the information remains truthful, complete, and not misleading; and
  • The company’s marketing communications related to the drug to make sure the information is truthful and not misleading.

Other Gonadorelin Products

Five gonadorelin (GnRH) products are FDA-approved to treat cystic ovaries in dairy cows, but only four are also FDA-approved for use with another drug for synchronizing estrous cycles in lactating dairy cows: GONAbreed, Factrel Injection, Fertagyl, and CYSTORELIN.

FDA-Approved GnRH Products for Use with Another Drug for Estrous Synchrony

Drug Information Factrel® Injection GONAbreed® Fertagyl® CYSTORELIN®
Manufacturer Zoetis Inc. Parnell Technologies Pty. Ltd. Intervet, Inc. Merial, Inc.
Active Ingredient gonadorelin hydrochloride gonadorelin acetate gonadorelin acetate gonadorelin diacetate tetrahydrate
For Estrous Synchrony, Use With: Lutalyse® Injection or Lutalyse® HighCon Injection (dinoprost tromethamine injection) cloprostenol sodium Estrumate® (cloprostenol injection) cloprostenol sodium
Species/Class Lactating dairy cows  Lactating dairy cows and beef cows   Lactating dairy cows Lactating dairy cows and beef cows

Other than the uses listed in the table above, it is illegal to use GnRH products in cattle with another drug for estrous synchrony.

FDA’s Center for Veterinary Medicine (CVM) is committed to promoting and protecting animal health by ensuring that safe and effective drugs are available for animals. For more information, please contact CVM’s Education & Outreach Staff at 240-402-7002 or AskCVM@fda.hhs.gov.


FDA's Center for Veterinary Medicine

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