Tell FDA: Block Approval of GMO Heme

Plant-based meat products seem to be all the rage. They are billed as a healthier, more environmentally-friendly alternative to traditional meat, and the fad is catching on. Fast-food giant Burger King has announced the “Impossible Whopper,” a meatless version of their popular sandwich. What you probably haven’t been told is that these plant-based meats are made possible through a new form of genetic engineering that has undergone virtually no safety testing. Once again, the American consumer will be Big Food’s guinea pig—unless we speak up.

Tell Congress and the FDA that “heme” produced with synbio must be adequately tested before it is released to the public. Please send your message immediately.


  • Your Senators
  • Your Representative
  • Food and Drug Administration


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Dear [Decision Maker],

Some plant-based burgers are able to give the impression of "bleeding" like real meat because they release a compound called heme. Heme is found naturally in beef and is released during the cooking process. Heme can also be sourced from soy plants, specifically the roots, but it isn't sustainable. To circumvent this problem, companies that make plant-based burgers have created heme through synthetic biology (synbio).

The genetic code for the heme protein is inserted into genetically modified yeast. The yeast is then fed so it grows, replicates, and manufactures heme. The FDA recently approved this synbio "heme" as a color additive, which means that plant-based burgers with GMO heme can hit supermarket shelves, even though this form of heme has not been tested for safety or if it induces allergic reactions.

More and more foods are going to be produced using synbio in the future. Given the embarrassingly narrow definition of what constitutes a GMO that has been adopted by the federal government, none of the foods produced using synbio will have to be labeled as "bioengineered."

This is unacceptable. I am asking that GMO-produced heme be removed from the market until adequate testing has been conducted to confirm its safety.

[Your Name]
[Your Address]
[City, State ZIP]
[Your Email]