What Are Bully Sticks Made Of? Beware Of Sodium Metabisulfite

What Are Bully Sticks Made Of? Beware Of Sodium Metabisulfite

The purest bully sticks are made from just raw beef pizzle (bull penis) and some water (used for thawing and cleaning).

But some bully stick manufacturers are adding a chemical preservative, sodium metabisulfite, which was deemed by the FDA to be not safe for meat products.1 The FDA states, “sulfite preservatives should not be used in meats or food recognized as being a source of vitamin B1 (thiamine or thiamin).2

Yet 3 of the 14 bully stick manufacturers we talked to in 2021 are using this chemical preservative to help reduce odor in their bully sticks.

The concern with sodium metabisulfite for the FDA and other experts we consulted with is that it destroys B1 (thiamine), an essential nutrient that brain and nervous system function is dependent upon, and can lead to other negative side effects like allergic reactions.3 According to the FDA, “...sulfite preservatives are known to destroy vitamin B1 and vitamin B1 is an essential nutrient that participates in many biochemical pathways in the human and animal body.2

Sodium Metabisulfite

Although the FDA has deemed sodium metabisulfite to be unsafe in meat products, these bully sticks are still on the market. Unsurprisingly, we have not found any bully stick retailers labeling or disclosing that their bully sticks are made with this preservative.

For the safety and well-being of all dogs, we encourage dog parents to talk to your bully stick retailers to get verification from their distributors/manufacturers that sodium metabisulfite is not being used in the production of your bully sticks.

What The Experts Say

In addition to the FDA stating that sodium metabisulfite is not safe in meat products, we consulted with experts Ronny LeJeune, certified canine nutritionist of Perfectly Rawsome, and Dr. Derek Lowe, chemist and author of In the Pipeline, to get some more insight.

Ronny LeJeune, CertCN stated, “There is considerable evidence that shows this preservative (sodium metabisulfite) causes B1 deficiency as well as allergic reactions.”

Dr. Lowe was particularly concerned about the amount of sulfites remaining in the finished bully sticks that were made with sodium metabisulfite.  When we had these bully sticks lab-tested, those that used sodium metabisulfite had 132x more sulfites compared to the control bully sticks that were made without metabisulfite. This is an amount that, even in places (such as Europe, Canada, and Australia) where a limited amount of sodium metabisulfite is permissible in limited meats like ground beef and sausage, is 7x more than the maximum amount allowed.4

How We Began Researching Sodium Metabisulfite

Over the past couple of years, as we searched for additional bully stick manufacturers to work with we came across manufacturers (3 of the 14 manufacturers we talked to in 2021) using sodium metabisulfite in the production of their bully sticks.  At the time, we did not know much about this substance, just that the manufacturers claimed it was safe, but at the same time that it was a chemical preservative.

We looked more into it and could not find anything published regarding sodium metabisulfite use in bully sticks and its impact.  We felt the right thing to do was to do the research ourselves and determine if we felt this preservative was either harmless and okay to be used in our bully sticks (which we would disclose) or if not, to share with consumers our concerns.

As previously stated, we conclude that sodium metabisulfite use in bully sticks can be harmful to dogs and it should not be used.

Why Do Manufacturers Use Sodium Metabisulfite?

Manufacturers use sodium metabisulfite to reduce the odor of bully sticks and to achieve what they believe is a more desirable color in the bully sticks.

With the proper practices, sodium metabisulfite (or any other chemical preservative) is not needed to produce truly low odor bully sticks. These proper practices include using fresh and safely stored raw material, good cleaning and trimming of the raw material, and using the appropriate cooking times and temperatures.

Our Recommendation & What We Hope To Accomplish

As mentioned previously, for the safety and well-being of all dogs, we encourage dog parents to talk to your bully stick retailers to get verification from their distributors/manufacturers that sodium metabisulfite is not being used in the production of your bully sticks.

We hope that through raising consumer awareness we can help lead to more transparent labeling and ideally to drive bully stick manufacturers to stop using this preservative altogether.

If you are a Bully Bundles customer today rest assured that your bully sticks are always made without sodium metabisulfite.  And if you are not a customer today, but are considering becoming one, please know that we take great pride in providing high-quality, truly all-natural and low odor bully sticks, always made without sodium metabisulfite, that you can feel great about giving to your dog. You can find our bully sticks at bullybundles.com.

If you have any questions or would like to learn more, please don’t hesitate to reach out.

*We have reached out to share our findings with the FDA and AAFCO (The Association of American Feed Control Officials). As of this publication date, we have not received a response. We have also shared our research with the 3 bully stick manufacturers who told us they use sodium metabisulfite in the production of their bully sticks in hopes that this information will lead them to stop doing so.

Chelsea Barstow & Ryan Schoop

[email protected]

[email protected]


Related Article: The 5 Fascinating Steps to Making a Bully Stick


  1. CFR - Code of Federal Regulations Title 21. accessdata.fda.gov. (n.d.). Retrieved February 3, 2022, from https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=182.3766
  2. Thixton, S. (2016, April 10). Science in Australia concerning to pet owners in the US. Truth about Pet Food. Retrieved March 9, 2022, from https://truthaboutpetfood.com/science-in-australia-concerning-to-pet-owners-in-the-us/#:~:text=The%20sulfite%20preservatives%20permitted%20in,sodium%20sulfite%2C%20and%20sulfur%20dioxide
  3. Singh M, Thompson M, Sullivan N, Child G. Thiamine deficiency in dogs due to the feeding of sulphite preserved meat. Aust Vet J. 2005 Jul;83(7):412-7. doi: 10.1111/j.1751-0813.2005.tb13078.x. PMID: 16035180.
  4. D'Amore, Teresa & Taranto, Aurelia & Berardi, Giovanna & Vita, Valeria & Chiaravalle, Eugenio & Iammarino, Marco. (2020). Sulfites in meat: Occurrence, activity, toxicity, regulation, and detection. A comprehensive review. Comprehensive Reviews in Food Science and Food Safety. 19. 10.1111/1541-4337.12607.