For Consumers >

This site provides technical and program information for veterinarians and farmers. If you are a consumer looking for general information, please visit the IMPROVEST® (gonadotropin releasing factor analogdiphtheria toxoid conjugate) Consumer Resource Center.

When it comes to growing the pork chain, experience the Intact Impact with IMPROVEST®. It works like an immunization, using the pig's immune system to naturally and temporarily reduce odor-causing compounds. You get the full benefits of intact males' growth and feed efficiency, without the downside, as well as more pork and more profit.1 All thanks to the Intact Impact.


IMPROVEST® is an FDA-approved veterinary prescription product that is a safe and effective alternative to physical castration to manage unpleasant aromas that can occur when cooking pork from some male pigs. It’s a protein compound that works like an immunization to temporarily protect against off-odors in pork. Its related global brand, IMPROVAC®, has been used successfully by farmers in other countries for more than 10 years.


A panel of economists estimated the impact of immunological castration (IC) vs physical castration (PC).1
They concluded that:

  • IC barrows generate a potential increase of $5.32/head in net income (after product plus administration costs of $5.00/head).
  • This value is comprised of benefits due to:
    • Cessation of physical castration (direct cost savings, fixed-costs dilution, increase in profit from saved pigs).
    • Increased revenue (heavier carcasses, higher average premium due to reduction in weight variation).
    • Feed savings (heavier pigs with less feed).
  • The average optimal carcass weight for IC barrows is 10-12 lb heavier on live-weight basis (4-6 lb in carcass weight) over PC barrows when both are finished to their respective, different optimal carcass weight.
  • For packers, the expected estimated net total return from IC barrows averages $5.04/carcass.
  • These benefits from IMPROVEST® are consistent in multiple marketing scenarios, even in challenging market situations when optimal carcass weights are reduced.

To learn more about IMPROVEST® economics, click here >

As male pigs mature, their bodies naturally produce substances that can cause an off-odor to be released when the pork is cooked. While the odor creates no safety issue, nearly 50% of consumers2, especially women, are sensitive to these unpleasant smells. These odors need to be controlled to ensure a high quality eating experience. Traditionally, farmers have physically castrated male pigs to control these off-odors.

To learn more about off-odor and its control, click here >

Important Safety Information:

Pregnant women should not administer IMPROVEST®. Women of childbearing age should exercise extreme caution when administering this product. Exercise special care to prevent accidental self-injection because of negative effects on reproductive physiology in both men and women. However, there is no risk associated with consuming pork from animals administered this product. IMPROVEST® should not be used in female pigs, barrows, or male pigs intended for breeding. Please see Brief Summary of Prescribing Information.

For more information, please see the full Prescribing Information.

1. Buhr BL, Hurley T, Tonsor G, Zering K, DiPietre D. Comprehensive economic analysis of Improvest adoption by the US pork industry. Am Assoc Swine Vet. 2014, 201-206.
2. Gilbert A, Wysocki C. The Smell Survey. National Geographic. 1987;172:4,514-525.

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